Biological Sciences

PCR (Polymerase Chain Reaction)

2020-07-13T00:43:00.001-07:00

PCR

Polymerase chain reaction (PCR) is a method widely used to rapidly make millions to billions of copies of a specific DNA sample, allowing scientists to take a very small sample of DNA and amplify it to a large enough amount to study in detail. PCR was invented in 1984 by the American biochemist Kary Mullis at Cetus Corporation. It is fundamental to much of genetic testing including analysis of ancient samples of DNA and identification of infectious agents. Using PCR, copies of very small amounts of DNA sequences are exponentially amplified in a series of cycles of temperature changes. PCR is now a common and often indispensable technique used in medical laboratory and clinical laboratory research for a broad variety of applications including biomedical research and criminal forensics.

The majority of PCR methods rely on thermal cycling. Thermal cycling exposes reactants to repeated cycles of heating and cooling to permit different temperature-dependent reactions – specifically, DNA melting and enzyme-driven DNA replication. PCR employs two main reagents – primers (which are short single strand DNA fragments known as oligonucleotides that are a complementary sequence to the target DNA region) and a DNA polymerase. In the first step of PCR, the two strands of the DNA double helix are physically separated at a high temperature in a process called Nucleic acid denaturation. In the second step, the temperature is lowered and the primers bind to the complementary sequences of DNA. The two DNA strands then become templates for DNA polymerase to enzymatically assemble a new DNA strand from free nucleotides, the building blocks of DNA. As PCR progresses, the DNA generated is itself used as a template for replication, setting in motion a chain reaction in which the original DNA template is exponentially amplified.

Almost all PCR applications employ a heat-stable DNA polymerase, such as Taq polymerase, an enzyme originally isolated from the thermophilic bacterium Thermus aquaticus. If the polymerase used was heat-susceptible, it would denature under the high temperatures of the denaturation step. Before the use of Taq polymerase, DNA polymerase had to be manually added every cycle, which was a tedious and costly process.

Applications of the technique include DNA cloning for sequencing, gene cloning and manipulation, gene mutagenesis; construction of DNA-based phylogenies, or functional analysis of genes; diagnosis and monitoring of hereditary diseases; amplification of ancient DNA; analysis of genetic fingerprints for DNA profiling (for example, in forensic science and parentage testing); and detection of pathogens in nucleic acid tests for the diagnosis of infectious diseases.

CRISPRCas9

2020-07-11T08:03:00.000-07:00

CRISPRCas9

CRISPR-Cas9 is a method of genome editing that exploits a natural DNA-snipping enzyme in bacteria, called Cas9 (CRISPR-associated protein 9) to target and edit particular genes. CRISPR stands for Clustered regularly interspaced short palindromic repeats, which are segments of DNA of a particular structure found widely in bacteria and archaea (prokaryotes). In the wild, the CRISPR-Cas9 system is part of the prokaryotic immune system, which can snip out of the genome DNA acquired from foreign sources such as phages (bacterial viruses). The same molecular machinery is now being used to enable genetic material to be cut from and pasted into the genomes of other organisms, including eukaryotes such as humans. It might offer a tool for curing genetically based diseases.

DNA has become a versatile polymeric substrate for making nanotechnological structures and artificial molecular-scale machinery for computation, pattern formation, and nanoscale assembly. For several decades now, these efforts have drawn on methods developed in and for biotechnology, and similarly they are likely to find ways of exploiting the advantages of the new technique called CRISPR/Cas9 for manipulating DNA. #CRISPRCas9

Antibody (Immunoglobulin)

2020-07-09T23:03:00.000-07:00

Antibody:
Antibody also called immunoglobulin, a protective protein produced by the immune system in response to the presence of a foreign substance, called an antigen.
When an alien substance enters the body, the immune system is able to recognize it as foreign because molecules on the surface of the antigen differ from those found in the body.
Antibodies are produced by specialized white blood cells called B lymphocytes (or B cells). When an antigen binds to the B-cell surface, it stimulates the B cell to divide and mature into a group of identical cells called a clone. The mature B cells, called plasma cells, secrete millions of antibodies into the bloodstream and lymphatic system.

Antibody structure:
The four-chain structure of an antibody, or immunoglobulin, molecule. The basic unit is composed of two identical light (L) chains and two identical heavy (H) chains, which are held together by disulfide bonds to form a flexible Y shape. Each chain is composed of a variable (V) region and a constant (C) region.

Antibodies are grouped into five classes according to their constant region.
Each class is designated by a letter attached to an abbreviation of the word immunoglobulin: IgG, IgM, IgA, IgD, and IgE.

CORONAVIRUS

2020-03-08T03:19:00.002-07:00

Coronaviruses (CoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases such as Middle East Respiratory Syndrome (MERS-CoV) and Severe Acure Respiratory Syndrome (SARS-CoV). A novel coronavirus (nCoV) is a new strain that has not been proviously identified in humans.

Coronaviruses are a family of viruses that cause disease in animals. Detailed investigations found that SARS-CoV was transmitted from civet cats to human and MERS-CoV from dromedary camels to humans. Several known coronaviruses are circulating in animals that have not yet infected humans.

The new coronavirus, officially called Covid-19 currently has fatality rate between 0.7 per cent to 3.4 per cent. This is much lower than fatality rates for Mers (30 per cent) and SARS (10 per cent), but still a significant threat. However, the new coronavirus (Covid-19) is spreading fast. The bulk cases and fatalities have been confined to China, but the virus is spreading internationally.

The source of the coronavirus is believed to be a "wet market" in Wuhan which sell both dead and live animals including fish and birds. Such markets pose a heightened risk of viruses, jumping from animals to humans because hygiene standards are difficult to maintain if live animals are being kept and butchered on site. Typically, they are also densely packed.

The animal source of the latest outbreak has not yet been identified, but the original host is thought to be bats. Bats were not sold at the Wuhan market but may have infected live chickens or other animals sold there.

Bats are host to a wide range of zoonotic viruses including Ebola, HIV and rabies.

Scientist in China believe that Covid-19 has mutated into two strains, one more aggressive than the other, which could make developing a vaccine more complicated.

It is impossible to say which way the disease will go but, on its current trajectory, it is likely to spread to more countries, affecting many more people. The number of cases is beginning to decrease in China but is increasing in the rest of the world.

Initial common symptoms of Covid-19 include fever, dry cough, tiredness and a general feeling of being unwell. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death. Symptoms are thought to appear between 2 and 10 days later after contracting the virus, but it may be up to 24 days

The virus is spread via droplets when a person coughs or sneezes. The droplets land on surfaces and are picked up on the hands of others and spread further. People catch the virus when they tough their infected hands to their mouth, nose or eyes. Standard recommendations to prevent infection include regular hand washing, covering mouth and nose when coughing and sneezing, thoroughly cooking meat and eggs. Avoid close contact with anyone showing symptoms or respiratory illness such as coughing and sneezing.

Various crazy conspiracy theories have been circulating that the virus somehow escaped from a Chinese lab, either by accident or design. However, that is categorically untrue and scientists studying its genetic code have linked it to bats. It probably then jumped to another animal, which passed it on to humans.

The 1918 Spanish Influenza or the H1N1 virus remains the most devastating flu pandemic in the modern history. The disease swept around the globe and is estimated to have caused between 50 to 100 million deaths. A version of the same virus was also behind the 2009 swine flu outbreak, thought to have killed as many as 575,400 people.

Other major influenza outbreaks include Asian flu in 1957, which led to roughly 2 million deaths, and Hong Kong flu which killed 1 million people 11 years later.

But coronavirus outbreaks have so far been far smaller. Sars eventually spread to 27 countries in total, infecting around 8000 people and killing 700

Dengue Fever

2019-09-03T09:23:00.002-07:00

Dengue fever is a painful, debilitating mosquito borne disease caused by any one of four closely related dengue viruses. These viruses are related to the viruses that cause West Nile infection and yellow fever.

An estimated 400 million dengue infections occur worldwide each year, with about 96 million resulting in illness. Most cases occur in tropical areas of the world, with the greatest risk occurring in the Indian sub continent, Southeast Asia, Southern China, Taiwan, the Pacific Islands, the Caribbean (except Cuba and the Cayman Islands), Mexico, Africa, Central and South America (except Chile, Paraguay, Argentina)

Dengue fever is transmitted by the bite of an Aedes mosquito infected with a dengue virus. Its peak biting periods are early morning and before dusk. The mosquito becomes infected when it bites a person with dengue virus in their blood. It cant spread directly from one person to another person.

Transmission of Dengue virus

Symptoms of Dengue fever usually begin four to six days after infection and last for up to 10 days, and may include sudden high fever, severe headaches, pain behind the eyes, severe joint and muscle pain, fatigue, nausea, vomiting, skin rash which appear two to five days after the onset of fever,mild bleeding such as nose bleeding, bleeding gums or easy bruising.

Sometimes symptoms are mild and can be mistaken for those of flu or another viral infection. Younger children and person who have never had the infection before tend to have have milder cases than older children and adults. However, serious problems can develop. These include dengue hemorrhagic fever, a rare complication characterized by high fever, damage of lymph and blood vessels, bleeding from the nose and gums, enlargement of the liver, and failure of the circulatory system. The symptoms may progress to massive bleeding, shock and death. This is called dengue shock syndrome (DSS).

People with weakened immune systems as well as those with a second or subsequent dengue infection are believed to be at greater risk for developing dengue hemorrhagic fever.

Doctors can diagnose dengue infection with a blood test to check for the virus or antibodies to it.

There is no specific medicine to treat dengue infection, If you think you may have dengue fever, you should use pain relievers with acetaminophen and avoid medicines with aspirin, which could worsen bleeding, You should also rest, drink plenty of fluids and see your doctor. If you start to feel worse in the first 24 hours after your fever goes down, you should get to a hospital immediately to be checked for complications.

The best way to prevent the disease is to prevent bites by infected mosquitoes, particularly if you are living in or travelling to a tropical area. This involves protecting yourself and making efforts to keepk the mosquito population down.

To protect yourself
Use mosquito repellents, even indoors
When outdoors, wear long sleeved shirts and long pants tucked into socks
When indoors, use air conditioning if available
Make sure window and door screens are secure and free of holes. If sleeping areas are not screened or air conditioned, use mosquito nets
If you have symptoms of dengue, speak to your doctor

To reduce the mosquito population, destroy the mosquito breeding grounds and spray insecticide in the affected areas. These include old tires, cans. or flower pots that collect rain. Regularly change the water in outdoor bird baths and pet's water dishes.

If someone in your home gets dengue fever, be especially vigilant about efforts to protect yourself and other family members from mosquitoes. Mosquitoes that bite the infected family member could spread the infection to others in your home.

FASTER WAY TO PRODUCE SPECIFIC HUMAN ANTIBODIES USING NANOPARTICLES

2017-07-29T10:34:00.000-07:00

Treating patient derived B cells with nanoparticles coated with CpG oligonucleotides to stimulate plasma cell production and challenge antigens to designate what kind of antibody the B cells should produce has resulted in the generation of specific, high affinity antibodies in just a few days that can recognize several strains of a pathogen at the same time. The researchers have already produced antibodies to a variety of bacterial and viral antigens, including tetanus toxoid and several strains of influenza, and were able to generate anti HIV antibodies from B cells donated by healthy volunteers who did not have the disease.

The new technique also eliminates the need for previous exposure to the pathogens, either by vaccination or infection.

"Our technique should allow the production of these antibodies within a shorter time frame in vitro and without the need for vaccination or blood/serum donation from recently infected or vaccinated individuals," said Dr. Facundo Batista, who led the team from the Francis Crick Institute in London, the Ragon Institute of Massachusetts General Hospital, MIT and Harvard. "In addition, our method offers the potential to accelerate the development of new vaccines by allowing the efficient evaluation of candidate target antigens."

Antibodies are produced by white blood cells called B cells, which recognize the calling card of a bacteria or virus called an antigen, and transform into plasma cells tailored to produce large numbers of antibodies to that specific antigen that fight off the disease. That's what happens in the body. When scientists tried to reproduce the process in the lab, they ran into problems getting the B cells to make the specific kind of plasma cells they needed because the challenge antigens were missing.

It was easy to get the B cells to proliferate by adding short DNA fragments called CpG oligonucleotides into their culture medium. CpG oligonucleotides activate a protein inside B cells TLR9, but TLR9 enthusiastically stimulates every B cell in the sample to respond, not just the tiny fraction capable of producing a particular antibody. Batista and his colleagues attached both CpG oligonucleotides and real challenge antigens to nanoparticles, added them to B cell cultures, and the plasma cells that resulted were both abundant and pathogen specific.

The team hopes their approach will help researchers produce therapeutic antibodies to treat infectious disease and other conditions, such as cancer.

For more information, go to the Journal of Experimental Medicine
http://jem.rupress.org/cgi/doi/10.1084/jem.20170633?PR
https://www.eurekalert.org/pub_releases/2017-07/rup-rdn071717.php

BACTERIOPHAGES: SMALL THINGS CONSIDERED

2017-07-29T09:51:00.001-07:00

Bacteriophages ("phages", for short) are viruses that infect prokaryotes (bacteria and archaea), harnessing the resources of the host cell to replicate vast numbers of themselves, eventually causing the cell to lyse and release the phage progeny, which then find new hosts and repeat the cycle. But that's just the textbook definition. What really hooks us in that some phages look just like lunar landers sent from alien spaceships. Merry Youle, one of STC's very own, has written a charming paean to her beloved subjects, a full length book all about "what makes the phages so fascinating, so intriguing, and so important."

Youle tells us, "This book was born of love, exasperation, and wonderment." Youle holds that phages are deserving of far more ink, and respect, than they've thus far received. They exist everywhere where their hosts thrive, including hydrothermal vents, acidic springs, the arctic tundra, and your own gut. They impact geothermal cycles, algal booms, and biodiversity. They are useful tools for genetic manipulation in the lab as well as in nature. and can serve as allies in treating bacterial infections.

Enterobacteriophage T4

http://schaechter.asmblog.org/schaechter/2017/07/a-star-studded-phantastic-voyage-of-phages.html

These "Indestructible" Animals Would Survive a Planet-Wide Apocalypse

2017-07-15T11:52:00.000-07:00

Even the most catastrophic astrophysical events couldn't wipe out the hardy tardigrade, researchers report.

A magnified view of a tardigrade, also known as a water bear

The world's most robust animals may very well survive until the sun stops shining.

Also known as water bears, tardigrades are tiny water dwelling creatures famed for their resiliency. The eight legged invertebrates can survive for up to 30 years without food or water and can endure wild temperature extremes, radiation exposure, and even the vacuum of space.

"Tardigrades are extremely hardy animals," says Thomas Boothby, a tardigrade researcher at the University of North Carolina. "Scientists are still trying to work out how they survive these extremes."

At a minimum, all of Earth's oceans would have to boil away to completely wipe out all life on the planet. Although Boothby said tardigrades are only known to survive high temperatures when dry and those species living in the sea would likely die before the waters boiled , tardigrades are still expected to avoid extinction until our sun swells up and becomes a red giant roughly six billion years from now, according to researchers who investigated the effects of various doomsday scenarios.

For details Tardigrades: The Indestructible Animals

Discoverer of penicillin Alexander Fleming warned against its overuse and the risk of resistant microorganisms as early as 1945, in his Nobel Prize lecture

2016-10-12T04:43:00.000-07:00

"The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant.

Here is a hypothetical illustration. Mr. X has a sore throat. He buys some penicillin and gives himself, not enough to kill the streptococci but enough to educate them to resist penicillin. He then infects his wife. Mrs. X gets pneumonia and is treated with penicillin. As the streptococci are now resistant to penicillin the treatment fails. Mrs. X dies. Who is primarily responsible for Mrs. X's death? Why Mr. X whose negligent use of penicillin changed the nature of the microbe.

Moral: If you use penicillin, use enough"

Sir Alexander Fleming shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Florey and Ernst Boris Chain for his discovery of the world's first antibiotic substance benzylpenicillin (Penicillin G) from the mould Penicillium notatum in 1928. He also discovered the enzyme lysozyme in 1923.

Fleming's Nobel Lecture reached from here:Nobel Lecture by Sir Alexander Fleming on December 11, 1945

Yoshinori Ohsumi: Autophagy from begining to end

2016-10-12T03:47:00.002-07:00

Yoshinori Ohsumi was influenced by his father, who was a professor of engineering at Kyushu University, He was familiar with academic life while he was growing up. But whereas his father worked in a very industrially oriented field, he was more interested in the natural sciences. In high school, he was interested in chemistry, so he entered the University of Tokyo to learn chemistry. He quickly discovered chemistry wasn't so attractive to him, because the field was already quite established. But he was lucky, he thinks, because the early 1960's was the golden age of molecular biology. He decided he wanted to work on that instead.

There were not very many molecular biology labs in Japan at that time. He joined Dr. Kazutomo Imahori's lab as a graduate student to study protein synthesis in E. coli. Unfortunately, he did not get very good results in his work, and, when he had finished his graduate studies, he discovered it was very difficult to find a good position in Japan. So, on Dr. Imahori's advice, he took a postdoctoral position with Dr. Gerald Edelman at The Rockefeller University in New York.

As a graduate student, he had worked on E. coli., but in Dr. Edelman's lab he switched to working on mammalian cell and developmental biology. He was supposed to establish a system for in vitro fertilization in mice, but he did not know very much about early embryology and he had only a very small number of eggs to work with. He grew very frustrated. Then, one and a half years later, Mike Jazwinski joined Edelman's lab, and he decided to work with him instead on studying DNA duplication in yeast. That was another huge leap for him, but it was also his first introduction to yeast cells, which he has worked with ever since.

Finally, he was offered a position as a junior professor in Yasuhiro Anraku's lab at the University of Tokyo and was able to return to Japan

For complete interview, read this 2012 interview conducted by Journal of Cell Biology, where Yoshinori Ohsumi explains his progress within the field of autophagy.

Autophagy genes are discovered by Yoshinori Ohsumi for the greatest benefit to mankind

2016-10-12T02:25:00.001-07:00

Autophagy has been known for over 50 years but its fundamental importance in physiology and medicine was only recognized after Yoshinori Ohsumi's paradigm-shifting research in the 1990's.

The experiment by 2016 Medicine Laureate Yoshinori Ohsumi demonstrated that autophagy exists in yeast. Ohsumi studied thousands of yeast mutants and identified 15 genes that are essential for autophagy. But even more importantly, he now had a method to identify and characterize key genes involved in this process. This was a major break through and Ohsumi published the results in 1992. First key publication: Takeshige, K., Baba, M., Tsuboi, S., Noda, T, and Ohsumi, Y. (1992). Autophagy in yeast demonstrated with proteinase-defifient mutants and conditoins for its induction. Journal of Cell Biology 119, 301-3011

The term "autophagy" was coined by Christian de Duve in 1963. Our bodies are made up of cells that contain organelles, components with various functions, Albert Claude's research with the newly developed electron microscope and his methods for separating the various parts of pulverized cells using a centrifuge opened up new opportunities for studying cells in detail. In 1995, Christian de Duve discovered previously unknown organelles in the cell, lysosomes. These have important functions in decomposing different types of materials, such as bacteria and parts of cells that have worn out. In 1974 de Duve shared the Nobel Prize in Medicine for discovering the lysosome.

Thanks to Ohsumi and others following in his footsteps, we now know that autophagy controls important physiological functions where cellular components need to be degraded and recycled. Autophagy can rapidly provide fuel for energy and building blocks for renewal of cellular components, and is therefore essential for the cellular response to starvation and other types of stress. After infection, autophagy can eliminate invading intracellular bacteria and viruses. Autophagy contributes to embryo development and cell differentiation. Cells also use autophagy to eliminate damaged proteins and organelles, a quality control mechanism that is critical for counteracting the negative consequences of aging.

Disrupted autophagy has been linked to Parkinson's disease, type 2 diabetes and other disorders that appear in the elderly. Mutations in autophagy genes can cause genetic disease. Disturbances in the autophagic machinery have also been linked to cancer. Intense research is now ongoing to develop drugs that can target autophagy in various diseases.

Nobel Prize 2016 in Physiology or Medicine

2016-10-11T11:25:00.000-07:00

The 2016 Nobel Prize in Physiology or Medicine is awarded to Yoshinori Ohsumi for his discoveries of mechanisms for autophagy which was announced on 3rd October 2016

This year's Nobel Laureate discovered and elucidated mechanisms underlying autophagy, a fundamental process for degrading and recycling cellular components.

The word autophagy originates from the Greek words auto- meaning self and phagein- meaning to eat. Thus, autophagy denotes "self eating." Its a process whereby the eukaryotic cell can recycle part of its own content. This concept emerged during the 1960's, when researchers first observed that the cell could destroy its own contents by enclosing it in membranes, forming sack like vesicles that were transported to a recycling compartment, called lysosome, for degradation. Unlike other cellular degradation machineries, autophagy removes long lived proteins, large macro molecular complexes and organelles that have become obsolete or damaged. Difficulties in studying the phenomenon meant that little was known until, in a series of brilliant experiments in the early 1990's. Yoshinori Ohsumi used baker's yeast to identify genes essential for autophagy. He then went on to elucidate the underlying mechanisms for autophagy in yeast and showed that similar sophisticated machinery is used in our cells.

Ohsumi's discoveries led to a new paradigm in our understanding of how the cell recycles its content. His discoveries opened the path to understanding the fundamental importance of autophagy in many physiological processes, such as in the adaptation to starvation or response to infection. Mutations in autophagy genes can cause disease, and the autophagic process is involved in several conditions including cancer and neurological disease.

Yoshinori Ohsumi is a professor at the Tokyo Institute of Technology since 2009

BacteriaBioengineeringStorage

2010-12-07T22:08:00.000-08:00

A new method of data storage that converts information into DNA sequences allows you to store the contents of an entire computer hard-drive on a gram's worth of E coli and perhaps considerably more than that.

Source:

Collection of Title of Dissertation (Updated)

2010-05-19T16:00:00.001-07:00

A Comprehensive Collection of Title of Dissertations Submitted by Students of M.Sc. Microbiology to The Central Department of Microbiology, Tribhuvan University

Find here more Collection of Title of Dissertation (from 1 to 172)

173. Lower respiratory tract infection a socio-medical aspect. By: Punita Gauchan

174. Study on performance of waste water treatment plant at guheshwari. By: Chandra Shekhar Rajaure

175. A prospective study on microbiology of lower respiratory tract infection and antibiotic sensitivity profile with interest in multidrug resistance and extended spectrum of betalactamase strains. By: Jaya Sharma

176. Prevalence of Lymphatic filariasis in Parsa District of Nepal. By: Surath Upadhaya

177. Field evaluation of the OPTimal test for the rapid diagnosis of malaria. By: Puspa Raj Pandey

178. An epidemiological study of malaria in Kanchanur District during 2003. By: Deepak Joshi

179. Microbiology of Bacteraemia and septicaemia in patients visiting Tribhuvan University, Teaching Hospital (TUTH) Kathmandu. By: Yadav Wagley

180. Study on heavy metal resistant bacteria in the waste water treatment plant at Guheshwori. By: Anjita Rajbanshi

181. Prevalence of catheter associated urinary tract infection as Hospital acquired infection in TUTH. By: Abhilasha Gurung

182. Comparative evaluation of four different tests in the diagnosis of Visceral leishmaniasis in Nepal. By: Amin Khadka

183. Microbial quality evaluation of milk and butter with special reference to the milk pathogens and MBRT test. By: Toya Nath Sapkota

184. An epidemiological study of anti-tuberculosis drug resistance pattern in the pulmonary tuberculosis patients visiting national tuberculosis centre. By: Komal Raj Rijal

185. A Hospital study of urinary tract infection among pregnant women visiting Lumbini Zonal Hospital, Butwal. By: Munal Subedi

186. Study on the impairment of liver kindney and pancreas in Hepatitis B and C positive cases. By: Amrit M S Maharjan

187. Enteropathogens associated with acute diarrhoea in patients visiting National Public Laboratory, Teku. By: Ranjan K. C

188. Study on nasopharyngeal pneumococcal carriage enteroparasitic infectations in children. By: Bijaya Malla

189. Study on the prevalence of Salmonella species from blood sample of the patients visiting national public health  laboratory, Teku. By: Sabina Shrestha

190. Prevalence of Methicillin resistant Staphylococcus aureus (MRSA) in children visiting Kanti children's Hospitals. By: Santosh Thapa

191. Bacteriological profile of bacteraemia and speticaemia among patients of infective endocarditis. By: Narayan Prasad Kandel

192. Microbial study of chronic obstructive pulmonary disease in patients admitted in Nepal Medical College Teaching Hospital, Jorpati. By: Deepu Pudasaini

193A prospective study of urinary tract infections in female patients attending Kathmandu Model Hospital. By: Puja Shrestha

194. Prevalence of Aeromonas in different clinical samples and water with special interest in Gastroenteritis. By: Nirajan Thapa Kshetry

195. Serostatus of rheumatoid factor, c-reactive protein, antistreptolysin-o and uric acid in patients visiting OM Hospital and research centre. By: Raj Kumar Karki

196. Study of urinary tract infection among kidney transplant patients visiting National Public Health Laboratory, Teku.By: Gokarna Raj Ghimire

197. Prevalence of vulvovaginal giardiasis in females attending gynecological outpatient department of Tribhuvan University Teaching Hospital. By: Bijaya Bajracharya

198. Seroprevalence of torch in Nepalese women of childbearing age and evaluation of biochemical parameters. By: Pradeep Kafle

199. Detection of enteric pathogens (Vibrio Cholerae and Escherichia coli 0157) in childhood diarrhoeal cases. By: Roshani Maharjan

200. Prevalence of Urinary tract infection and candiasis of   pregnant women at community based reproductive health care & counseling center of Kirtipur Municipality. By: Sulochana Basnet (Mahat)

201. Detection of Enteropathogens (Salmonella spp, Shigella spp and Parasites) in the stool specimen of children suffering from diarrhea and admitted at kanti children Hospital. By: Diksha Khadka

202. Evaluation of antimicrobial activities of some medical plants. By: D Radha

203. Seroprev valence of hepatitis B and HIV among volunteer blood donors of Kathmandu. By: Dinesh Thapa

204. Prevalence of lower respiratory tract pathogens (bacterial) in Nepalese HIV/AIDS Patients. By: Dipendra Gautam

205. Study of Bacteraemia in malnourished children admitted to Kanti children's hospital. By: Prakash Chandra Amatya

206. Recovery of sliver from used X-Ray films using alkaline protease extracted from Bacillus spp. By: Dal Bahadur Khatri

207. Screening of soil bacillus species for ß lactamase activity. By: Niraj Nakarmi

208. Genetic variability of Mycobacterium leprae in Nepal. By: Susan Pandey

209. Prevalence of multidrug resistant strains with reference to extended spectrum beta-lactamase producing strains among the bacterial pathogens isolated from different clinical samples at Tribhuvan University Teaching Hospital. By:Rajdeep Bomjan

210. Antibiotic susceptibility profile of bacterial pathogens in urinary trace infection with special reference to extended spectrum beta lactamase (ESBL) oridycubt straubs. By: Trishna Manandhar

211. Study on Microbiology of urinary tract infection and the prevalence of multidrug resistant strains among the bacterial pathogens. By:Deepa Shrestha

212. Tuberculosis and HIV co-infection in HIV-AIDS persons of Nepal. By: Govinda Prasad Dhungana

213. Cross-sectional study of respiratory pathogenes and their antibiotic susceptibiligy pattern in Tribhuvan Unversity Teaching Hospital. By: Uma Shrestha

214. Loop-mediated isothermal amplification for direct detection of mycobacterium tuberculosis in sputum samples. By: Ajaya Poudel

215. A study on etiological agents of bacteraemia and antibiotic susceptibiligy pattern of isolates. By: Niroj Man Amatya

216. Biodiversity and bioactivity of endophytic fungi of tsuga dumosa D. Don. By: Anjana Upadhaya

217. Vermicomposting, enrichment of vermicompost by azotobacter chroococcum and response on phaseolus bean. By: Yukti Basnet

218. Prevalence of malaria and hepatitis B among Nepalese blood donors. By: Bishnu Bhakta Dhungel

219. Evaluation of different staining techniques (Ziehl neelsen stain, Kinyoun stain, Modified cold stain and fluorochrome stain) for the diagnosis of pulmonary tuberculosis. By: Deepika Shrestha

220. Study of delta encotoxin immunocrossreactivity of bacillus thuringiensis isolates from khumbu base camp of the Everest Region. By: Upendra Thapa Shrestha

221. Study of genetic polymorphism among bacillus thuringensis isolates from Khumbu Base Camp of Everest Region by randomly amplified polymorphic DNA polymerase Chain Reaction. By: Gyan Sundar Sahukhal

222. Study of prevalence of enteric fever and the assessment of widal test in the diagnosis of typhoid fever. By: Samira Khatiwada

223. A prospective study on etiology of diarrhea with reference to multiple drug resistant enteric bacterial pathogens. By: Sirjana Devi Shrestha

224. Prevalence of intestinal parasitosis among HIV/HIDS patients of Kathmandu Valley and Dhulikhel. By: Sunil Maharjan

225. Microbiological study among diarrhoeal children in relation to cyclospora and rotavirus infection. By: Chamala Lama

226. Study of prevalence of intestinal parasitic infection among HIV seropositive subjects and high risk group for HIV infection in Bagmati Zone, Nepal. By: Navaraj Raj Adhikari

227. Assessment of therapeutic of anti-mallarial drug (chloroquine) for plasmodium vivax in kanchanpur district, Nepal. By: Dhan Kumar Pant

228. Study on intestinal infections by parasite and some bacteria among elderly people of Kathmandu Valley.By: Bikash Shakya

229. Microbial study of hospital environment and carrier pattern study among staff in Nepal Medical College Teaching Hospital. By: Jyoti Pant

230. Assessment of hazard analysis critical control point (HACCP) from restaurants of Kathmandu metropolitan city with respect to environmental condition. By: Poonam Thapa

231. Sero-epidemiology of Japanese encephalitis in Nepal. By: Shyam Prasad Dumre

232. A study on soil transmitted helminthiasis in Kathmandu Valley. By: Arina Shrestha

233. Study on the incidence of urinary tract infection in diabetic patients and the prevalence of multidrug resistant strains among the bacterial pathogenic isolates. By: Nisha Puri

234. Prevalence of bacterial and fungal agents causing lower respiratory tract infections in patients with human immunodeficiency virus (HIV) infection. By: Sanchita Dahal

235. Isolation and identifcaton of the etiolotical agent of pulmonary tuberculosis in patients visiting national tuberculosis center, Thimi, Bhaktapur. By: Sudeep Singh

236. Microbial flora among vstors and the hospital environment in ICU and SICU at TUTH. By: Shishir Sharma

237. A study on possible contribution of horizontal transmission in neonatal sepsis at TUTH. By: Sangeeta Shrestha

238. Prevalence of methicillin resistant staphylococcus aureus (MRSA) in clinical specimnets from patients and screening of nasal carriage of MRSA from Medical Staffs of Bir Hospital. By: Kiran Sapkota

239. Study of the disease citrus canker and field trial to find its effective control measure in “Kavre” Nepal.By: Dinesh Dhakal

240. Effect of dual inoculation of Rhizobium leguminosarum biovar p[haseoli and Piriformospora indica verma et al. on phaseolus vulgaris grown in the soil treated with vermicompost. By: Jeny Shrestha

241. Study on the effect of co-inoculation of bradyrhizobium japonicum and pirifirmospora indica verma et al. on glycine max (L.) merr. By: Rajani Shrestha

242. A study on microbiology of urinary tract nfection at Tribhuvan University Teaching Hospital Kathmandu Nepal. By: Shova Khanal

243. Evaluation of antibiacterial activity of some medicinal plants frequently used in respiratory and gastrointestinal diseases in Nepal. By: Olivia Thapa

244. Pattern of bacterial flora in various out patient departments of TUTH. By: Rachana Manandhar

245. A comparative study of different diagnostic methods for Mycobacterium tuberculosis in suspected patients visiting National Tuberculosis Centre, Thimi, Bhaktapur, Nepal. By: Asta Ram Khagi

246. Study on prevalence of common types of vaginitis (candidiasis, traichomoniasis and bacterial vaginosis) among the pregnant women visiting thapathali maternity hospital Kathmandu. By: Sarita Shrestha

247. Role of Glomus Microcarpum in the production of whear (triticum aestivum)  plants. By: Nirmala Dhungana

248. Study of bacteria causing urinary tract infection and their antimicrobial resistance trend at national public health laboratory. By: Padma Shrestha

249. Nalidxic acid resistant salmonella with decreased ciprofloxacin susceptibility. By: Rup Bahadur Kunwor

250. Corelation of secondary infection with peripheral level T lymphocyte with CD4 marker (CD$) count in HIV/AIDS patients. By: Shiva Ram Pant

251. A study on Microbiological and chemical quality of water of Kathmandu. By: Rama Gyawali

252. Study on seroprevalence of IgM Antibiodies against the agents of torch infections among the patients visiting National Public Health Laboratory. By: Sujata Lamichhane

253. Effect of dual inoculation of azotobacterchroococcum and piriformospora indica verma et al on oryza satwal croun in the soil treated with vermicompost. By: Kamil Prajapati

254. Microbiological study on gastroenteritis of children from Kanti Children's Hospital with reference to cyclospora and rotavirus infection. By: Shradha Chipalu

255. Comparative evaluation of microscopic and cultural examination in bacterial meningitis among the patients attending Kanti Children Hospital. By: Rojita Tuladhar

256. Study of drinking quality of Kathmandu Metropolitan areas and evaluation of antibacterial property of some medicinal plants against isolated enteric bacteria. By: Anup Muni Bajracharya

257. DNA fingerprinting of Mycobacterium tuberculosis isolates in Nepal using PCR-labelled is 6110 probe. By; Saraswoti Kadge

258. Use of Loop-mediated isothermal amplification (Lamp) for direct detection of Mycobacterium in sputum. By: Bal Ram Adhikari

259. Study of antibiotic susceptibility pattern of mycobacterium tuberculosis in pulmonary tuberculosis patients visiting national tuberculosis center, Thimim Bhaktapur, Nepal. By: Semuhang Subba

260. Assessment of drinking water quality of madhyapur-Thimi ans study of anti bacterial effect of lime juice against bacterial isolates. By: Bina Laxmi Jayana

261. Study the hospital environment of shahid gangalal national heart centre. By: Kamala Lamsal

262. Study on bacteriological profile of infected wound from patient's visiting to lumbini zonal hospital, butwal, Nepal. By: Yasoda Gyawali

263. Prevalence of bacteraemia and septicaemia among children attending kanti children hospital with special reference to salmonella spp. By: Deena Shrestha

264. Study on intestinal parasitic infections in tharu community of bardiya district. By: Pragya Sharma

265. Screening of mycobacterium tuberculoss by selective inhibition with para-nitrobenzoic acid, its cytochemical staining and drug susceptibility to primary anti-tubercular drugs. By: Sujaya Nepali

266. Microbiological and physico-chemical analysis of alcoholic beverages of Kathmandu Valley. By: Bhim Shrees

267. Study on drinking water quality of Kathmandu and attending susceptibiligy of isolates . By: Prashanna Raj Kafle

268. Seroprevalence of rubella in Nepal. By: Khagendra Prakash K. C

269. Reproductive tract infections among women attending gynaecological outpatient department Tribhuvan University Teaching Hospital. By: Madan Singh Bohara

270. Tuberculosis and human imuno-deficency virus co-infection in suspected TB patients. By: Sunita Maharjan

271. Study of biodiversity and bioactivity of endophytic fungi of some Himalayan conifers of Nepal. By: Srijana Thapaliya

272. Bacterial isolatres and their antibiogram from wounds and abscesses of surgical outpatients visiting bir hospital. By: Prashamsa Karkee

273. Comparison of the resistance ratio and proportikon methods for drug susceptibility testing of Mycobacterium tuberculosis isolated from patients visiting national tuberculosis centre. By: Sushma Acharya

274. Pattern of bacterial isolates and antibiogram from open wound infection an\mong the indoor patients of Bir Hoapital. By: Kiran Kumari

275. Comparative study of polymerase chain reaction (PCR) and loop-mediated isothermal amplification (Lamp) for direct detection of Mycobacterium tuberculosis in sputum. By: Binita Koirala

276. Sterid biosynthesis and embryonic stem cell proteins as putative predictive breast cancer biomarker. By: Khagendra Koirala

277. Enteropathogenic microorganisms in children under ten years of age attending Kanti Children's Hospital. By: Sarmila Tandukar

278. Seroprevalence of hepatitisc and HIV among blood donors in Kathmandu valley. By: Surendra Karki

279. Prevalence of soil transmitted parasites in raw vebetables of Kathmandu and stool samples of school children. By: Anil Shrestha

280. Estimation of incidence of HIV infection in Nepal by mode of transmissionamong various exposure groups. By: Rumika Maharjan

281. Genetic simalasrities among bacillus thuringiensis strains from different climatic zones of Nepal. By: Nirajan Bhattarai

282. Biochemical and molecular characterization of actinomycetes prosessing antibacterial properties from soil samples of kalapatthar, mounteverest region. By: Chiringma Sherpa

283. Screening of actinomycetes from soil samples of Kalapatthar mount everest region for antibiosis. By: Tara Devi Gurung

284. Immunological screening of actinomycetes of khumbu region of Nepal. By: Suman Thapa

285. Multidrug resistance among various clinical bacterial isolates and production of different types of B-lactamases with subsequent transfer mechanism by plasmid DNA analysis. By: Pankaj Baral

286. Isolation identification and plasmid profiling of multidrug resistant bacterial pathogens isolated from UTI patients. By: Sanjiv Neupane

287. An evaluation of 5% NaOCI microscopy method for the laboratory diagnosis of pulmonary tuberculosis. By: Suman Lama

288. Assessment of arsenic tolerant bacteria from arsenic contaminated groundwater in nawalparasi district of Nepal. By: Shree Krishna Shrestha

289. Isolation and characterization of arsenic tolerant microorganisms from tube well water of Nawalparasi, Nepal. By: Prerana Dhungana

290. Biochemical and genetic characterization of actinomycetes from  mount everest base camp. By: Manita Guragain

291. Perspectives of arsenic exposure and asymptomatic microbial infections in Nawalparasi District. By: Narendra Maden

292. Microbiological quality evaluation of dahi/yoghurt of Kathmandu Valley. By: Kashi Ram Ghimire

293. Evaluation of antivicrobial activities of medicinal plants against some fungi and antibiotic resistant bacteria. By: Bishnu Prasad Marasini

294. Urinary tract infection in diabetic microalbuminuric patients visiting B&B Hospital. By: Gridhari Rijal

295. A comparative study of IGM capture Elisa and particle agglutination assay for the diagnosis of Japanese Encephalitis among some Nepalese patients. By: Santa Raj Khanal

296. Study on antimicrobial activities of actinomycetes isolated from soils of different parts of khumbu region. By: Junu Koirala

297. Estimation and projection oif the trend of HIV/AIDS in Nepal till 2010 using estimation and projection pakage (EPP) software. By: Manoj Khadka

298. Cross-sectional study of urinary pathogens and their antibiotic susceptibility pattern with reference to extended spectreum beta lactamase (ESBL) producing strains in Kathmandu Model Hospital. By: Neelam Karna

299. Evaluation of antibacterial activities of medicinal plants. By: Naresh Maharjan

300. The study of antibacterial activities of common spices. By: Dinesh Maharjan

301. Antibiotic susceptibility pattern of salmonella isolates from blood sample of patients visiting Shree Birendra Hospital, Chauni. By: Barsha Gurung

302. Comparasion of blood culture and single slide agglutination widal test for the diagnosis of enteric fever. By: Minu K. C

303. Bacteriological profile and antibiotic susceptibility pattern of the isolates from infected burn wound at Kanti Children's Hospital. By: Rupa Nepal

304. Comparative evaluation of macroscopic, microscopic, serological and cultural examination of csf in bacterial memingitis. By: Nabaraj Dahal

305. Study on HIV and sexually transmitted infections among the female commercial sex workers of Kathmandu Valley. By: Prakash Shrestha

306. Screening of antimicrobial activity of actinomycetes from soil samples of manang region of Nepal and their biological characterization. By : Rishi Baniya

307. Fluoroquinolone susceptibiligy pattern of the salmonella isolates from enteric fever patients visiting to National Public Health Laboratory, Nepal. By: Dhiraj Acharya

308. Sero-epidemiology of Japanese encephalitis in some selectedhospitals of Nepal. By: Krishna Prasad Pant

309. Sero-epidemiology of dengue virus infection in the post monsoon period I terai region of Nepal. By: Ramesh Pun

310. Bacteriological profile of urine of postoperative patients undergone open heart surgery at Shahid Gangalal National Heart Centre, Nepal. By: Supriya Sharma

311. Transfusion transmissible infections among blood donors in Kathmandu, Nepal. By: Ashish Chandra Shrestha

312. Bacteriological and histological profile of heart valves resected from infective endocarditis patients. By: Sulochana Manandhar

313. Prevalence of helicobacter pylori among dyspeptic patients attending Bir Hospital, Nepal. By: Shailaja Adhikari

314. Isolation, identification and antibiotic sensitivity testing of salmonella serovars from enteric fever suspected patients visiting Bir Hospital. By: Manita Aryal

315. Antibiotic susceptibility pattern of salmonella from blood of suspected enteric fever patients attending Patan Hospital. By: Krishna Govinda Prajapati

316. Seroprevalence of hepatitis B virus among blood donors in Jhapa, Nepal. By: Hemanta Khanal

317. Bacterioloigcal profiles of tracheal aspirates of patients attending National Institute of Neurolobical and allied sciences. By: Pratirodh Koirala

318. Evaluation of the three commercially availavle elisa test kits for the detection of Anti- HIV antibodies. By: Avishekh Gautam

319. Spectrum and antibiotic susceptibility pattern of bacterial isolates causing conjunctivitis among the patients visiting B.P. Koirala lions center for ophthalmic studies. By: Archana Bhattarai

320. Cholera incidence among diarrhoeal patients visiting national public health laboratory, Nepal. By: Rabindra Karki

321. Bacterioogy of chronic dacryocystitis and antibiotic susceptibiligy pattern of isolated bacteria. By: Anita Bhattarai

322. Isolation and characterization of salmonella from drinking water samples of urban water supply system of Kathmandu. By: Esha Shrestha

323. Strain typing of mycobacterium leprae isolates from Nepal uning variable number of tanden repeats. By: Pratibha Thapa

324. Use of minisatellite genetic profiling with clinical analysis of leprosy patients in Nepal. By: Binita Adhikari

Source: Microbiological Abstracts, Published by MISAN, Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu, Nepal.

Advice for potential biology graduate students

2010-02-28T11:04:00.000-08:00

There are a few things to keep in mind before you apply for graduate course in biology. First, be realistic about graduate school. Graduate school in biology is not a sure path to success. Many students assume that they will eventually get a job just like their advisor's. However, the average professor at a research university has 3 students at a time for about 5 years each. So, over a career of 30 years, this professor has about 18 students. Since the total number of positions has been pretty constant, these 18 people are competing for one spot. So go to grad. school assuming that you might not end up at a reserach university, but instead a teaching college, or a government or industry job. All of these are great jobs, but it's important to think of all this before you go to school.
Second, choose your advisor wisely. Not only does this person potentially have total control over your graduate career for five or more years, but he/she will also be writing recommendation letters for you for another 5-10 years after that. Also, your advisor will shadow you for the rest of your life. People will always think of you as so-and so's student and assume that you two are somewhat alike. Finally, in many ways you will turn into your advisor. Advisors teach very little, but instead provide a role model. Consciously and unconciously, you will imitate your advisor. You may find this hard to believe now but fifteen years from now when you find yourself lining up the tools in your lab cabinets just like your advisor did, you'll see. Someone once said that choosing an advisor is like choosing a spouse after one date. Find out all you can on this date.

Finally, have your fun now. Five years is a long time when you are 23 years old. By the end of graduate school, you will be older, slower, and possibly married and/or a parent. So if you always wanted to walk across Nepal, do it now. Also, do not go to a high-powered lab that you hate assuming that this will promise you long term happiness. Do something that you have passion for, work in a lab you like, in a place you like, before life starts throwing its many curve balls.

If, after reading this, you still want to apply for grad study, apply now.

Concepts in Biology: Laboratory Manual

Nobel Prize for RIBOSOME researchers

2009-12-12T18:41:00.000-08:00

Three scientists who showed how the information encoded on strands of DNA is translated into thousands of proteins that make up living matter will share the 2009

WHO backs anti-diarrhoea vaccine

2009-06-05T14:00:00.000-07:00

-->

WHO backs anti-diarrhoea vaccine

The World Health Organization says a vaccine which can prevent a diarrhoea and vomiting virus should be given to all children as a routine vaccination.

Rotavirus causes more than 500,000 diarrhoeal deaths and two million hospitalisations a year among children.

Over 85% of deaths occur in developing countries in Africa and Asia.

International experts welcomed the WHO's recommendations, based on new research, but UK scientists have said the vaccine is too costly.

'Milestone'

The WHO's Strategic Advisory Group of Experts (SAGE) made its recommendations after new data from clinical trials.

The clinical trial, which involved a range or organisations including the Global Alliance for Vaccines and Immunisations (GAVI) and drug company GlaxoSmithKline (GSK), which makes the vaccine plus researchers in South Africa and Malawi, found that rotavirus vaccine significantly reduced severe diarrhoea episodes.

The WHO's Dr Thomas Cherian, said: "This is a tremendous milestone in ensuring that vaccines against the most common cause of lethal diarrhoea reach the children who need them most."

But the WHO said, because there were other causes of diarrhoea, it was also important to improve water quality, hygiene, and sanitation and ensure oral rehydration solutions and zinc supplements were available.

Dr Tachi Yamada, president of the Global Health Program at the Bill and Melinda Gates Foundation, said: "This WHO recommendation clears the way for vaccines that will protect children in the developing world from one of the most deadly diseases they face.

"We need to act now to deliver vaccines to children in Africa and Asia, where most rotavirus deaths occur."

Dr Julian Lob-Levyt, chief executive officer of GAVI, said: "This represents another important step in our ability to achieve significant impact on under-five deaths in the world's poorest communities and make progress towards the Millennium Development Goals.

"We are extremely excited about the potential to offer African and Asian countries funding to introduce rotavirus vaccines."

'Price cut'

There are around 130,000 episodes of gastroenteritis caused by rotavirus each year in the UK.

Around 12,700 children are hospitalised, and four die each year.

The Joint Committee on Vaccination and Immunisation, which advises the government, said in February that it would only consider recommending the vaccine if its price were significantly reduced.

In February, the JCVI said: "Rotavirus vaccination would reduce the incidence of rotavirus in the population.

"However, the cost-effectiveness analysis showed that, based on current vaccine prices, universal vaccination of young children significantly exceeded the commonly accepted threshold for cost-effective healthcare interventions.

"Introduction of rotavirus vaccines may only become cost-effective if the vaccine price is reduced significantly."

Professor Andrew Hall, chairman of the JCVI, said the committee always kept vaccines under review and considered new information.

'Breakthrough' in malaria fight

2009-05-29T14:51:00.000-07:00

-->

Australian scientists have identified a potential treatment to combat malaria.

Researchers in Melbourne believe their discovery could be a major breakthrough in the fight against the disease.
The malaria parasite produces a glue-like substance which makes the cells it infects sticky, so they cannot be flushed through the body.
The researchers have shown removing a protein responsible for the glue can destroy its stickiness, and undermine the parasite's defence.
The malaria parasite - Plasmodium falciparum - effectively hijacks the red blood cells it invades, changing their shape and physical properties dramatically.
Among the changes it triggers is the production of the glue-like substance, which enables the infected cells to stick to the walls of the blood vessels.
This stops them being pased through the spleen, where the parasites would usually be destroyed by the immune system.
Painstaking tests
The Australian team developed mutant strains of P. falciparum, each lacking one of 83 genes known or predicted to play a role in the red cell remodeling process.
Systematically testing each one, they were able to show that eight proteins were involved in the production of the key glue-like substance.
Removing just one of these proteins stopped the infected cells from attaching themselves to the walls of blood vessels.
Professor Alan Cowman, a member of the research team at the Walter and Eliza Hall Institute of Medical Research, said targeting the protein with drugs - or possibly a vaccine - could be key to fighting malaria.
"If we block the stickiness we essentially block the virulence or the capacity of the parasite to cause disease," he said.
Malaria is preventable and curable, but can be fatal if not treated promptly. The disease kills more than a million people each year. Many of the victims are young children in sub-Saharan Africa.

Malaria parasites 'resist drugs'

2009-05-29T13:59:00.000-07:00

International scientists say they have found the first evidence of resistance to the world's most effective drug for treating malaria.

They say the trend in western Cambodia has to be urgently contained because full-blown resistance would be a global health catastrophe.
Drugs are taking longer to clear blood of malaria parasites than before.
This is an early warning sign of emerging resistance to a disease which kills a million people every year.
Until now the most effective drug cleared all malaria parasites from the blood within two or three days but in recent trials this took up to four or five days.
It is unclear why the region has become a nursery for the resistance - but the local public health system is weak, and the use of anti-malaria drugs is not properly controlled.
Drug defence
The artemesinin family of drugs is the world's front-line defence against the most prevalent and deadly form of malaria.
Two teams of scientists, working on separate clinical trials, have reported seeing the disturbing evidence that the drugs are becoming much less effective.
There is particular concern because previous generations of malaria drugs have been undermined by resistance which started in this way, in this part of the world, our correspondent reports.
The World Health Organization warned in 2006 there was a possibility the malaria parasite could develop a resistance to artemesinin drugs, and that there was particular concern about a decreased sensitivity to the drug being seen in South East Asia.
It urged drug firms to stop selling artemesinin on its own in order to prevent resistance building up.
Early results from two studies by US and UK teams have both revealed the early stages of resistance.
Between a third and a half of patients in the US study saw delayed clearance of the malaria parasite.
In the UK study, patients in the Cambodia arm of the trial took almost twice as long to clear the parasite as a comparison group in Thailand.
Professor Nick Day, director of the Mahidol-Oxford Tropical Medicine Research Unit which is carrying out the UK study, said: "Twice in the past, South East Asia has made a gift, unwittingly, of drug resistant parasites to the rest of the world, in particular to Africa," he said.
"That's the problem. We've had chloroquine and SP (sulfadoxine pyrimethamine) resistance, both of which have caused major loss of life in Africa," he said in reference to earlier generation anti-malarial drugs.
"If the same thing happens again, the spread of a resistant parasite from Asia to Africa, that will have devastating consequences for malaria control," he said.
Prof Brian Greenwood, Professor of Tropical Medicine (Oxford Handbook of Tropical Medicine (Oxford Handbooks Series)) at the London School of Hygiene and Tropical Medicine, described the findings as a matter for concern, even though treatment still worked if a full course of artemisinin combination therapy (ACT) was taken.
"There is currently no need for panic but it would be serious if these partially resistant parasites reached Africa where great gains in malaria control are currently being made using ACTs and insecticide-treated bed nets," he said.
Health systems
Cambodia has long been a laboratory for malaria investigators and a nursery of anti-malaria drug resistance.
Alongside a weak public health system and poorly-controlled drug use, there are many fake drugs, produced by international criminals.
These fakes often contain a small amount of the real drug to fool tests, which can also help to fuel resistance.
Those working to control malaria are calling for urgent action to contain this emerging resistance.
If it strengthens and spreads, they warn, many millions of lives will be at risk. About half the world's population faces exposure to the disease.

Polymerase Chain Reaction (PCR)

2009-03-05T13:42:00.001-08:00

Polymerase Chain Reaction (PCR) is molecular biological technique used for amplifying (creating copies of) DNA without the use of living organisms such as E coli, yeast. It is used in medical and biological research laboratories for detection of hereditary diseases, diagnosis of infectious diseases, identification of genetic fingerprints, cloning of genes and paternity testing.

The concept of PCR was at first put forward by H Ghobind Khorana et al in 1971 but is seemed to be impractical before gene sequencing and viable thermostable DNA polymerase. Later, after 15 years in 1986 Kary Mills developed the PCR technique. PCR is a process by which DNA is artificially multiplied through repeated cycles of duplication in the presence of DNA polymerase.

The PCR process was patented by Cetus Corporation where Kary Mills worked where he developed the technique. Taq polymerase enzyme was also covered by the patent. The pharmaceutical company Hoffmann-La-Roche purchased the right to patent in 1992 and currently holds them.

DNA polymerase occurs naturally in living organisms and functions to create copies of DNA when cell divides. It functions by binding to single stranded DNA and creating complementary strand. The original concept of PCR technique developed by Mills uses the enzyme in vitro. Double stranded DNA was separated into two single strands by heating at 96 degree C. However, at this high temperature, DNA polymerase was destroyed and required to be replenished after heating stage of each cycle. Thus, it required great deal of time, large amount of DNA polymerase and continued attention throughout the PCR process.

Later, this PCR process was modified by using DNA polymerase obtained from thermophilic bacteria that grow in geysers at 110 degree C. This DNA polymerase was thermostable and do not break down when the reaction mixture was heated to separate strands.

The first thermostable DNA polymerase was obtained from Thermus aquaticus and called Taq polymerase. One of the disadvantages of this Taq polymerase was that it sometimes maked mistakes while making copies of DNA leading to mutation of DNA sequences since it lacked 3’-5’ proofreading exonuclease enzyme. The polymerase Pwo and Pfu obtained from Archaea contained exonuclease enzyme and reduced the mistakes while making copies of DNA. The combination of Taq and Pfu is available now a days that provides both fidelity and accurate amplification of DNA.

PCR amplifies short, well defined DNA fragment. It requires a single gene or just a par of gene. As opposed to living organism, PCR can make copies of only short DNA fragment upto 10 kb ie 1000 base pairs. DNA is double stranded and therefore it is measured as complementary DNA building block (nucleotides as base pairs).

PCR requires
DNA template containing the region of DNA fragment to be amplified
Two primers determining the beginning and end of DNA fragment to be amplified
DNA polymerese to make copies of DNA fragment to be amplified
Nucleotide from which DNA polymerase synthesize DNA strand
Buffer for creating optimum chemical environment for DNA polymerase to perform

PCR is carried out in thermal cycler. It is a machine that cools and heats the reactions tubes within it in precise temperature that is required for each step of the reaction. Evaporation of the reaction mixture is prevented by placing heated lid on reaction tube or by placing thin oil layer on the reaction mixture.

Primer
DNA fragment to be amplified is determined by selecting the primer. Primers are artificial, short DNA strands upto 50 nucleotides that exactly match the beginning and end of the DNA strand to be amplified. They anneal with DNA template at these beginning and end points and DNA polymerase binds and begins synthesis of DNA strand.

The choice of the length of the primers and their melting temperature depends on several considerations. Melting temperature of primer- not to be confused with the melting temperature of DNA at firs step of PCR- is the temperature at which half of the primer binding sites would be occupied. Melting temperature increases with the length of the primer. Short primers would anneal at several points on the long DNA template resulting non specific copies. On the other hand, length of the primer is limited by melting temperature at which it melts. High melting temperature above 80 degree C will cause problem since the DNA polymerase is less active at this high temperature. The optimum length of primer is 20 – 40 nucleotide wit melting temperature of 60 – 75 degree C.

PCR has a series of 20-30 cycles and each cycle consists of 3 steps-
1st step- Double stranded DNA is heated at about 94-96 degree C to separate the strands. This step is called denaturation and breaks apart the hydrogen bond that binds together two DNA strands. Prior to the first cycle, DNA is denatured for extended time period in order to ensure that both template DNA and primers are separated into single strand. The time of this step is usually 1-2 minute/s.

2nd step- After denaturation, temperature is lowered so that primer anneals with the single stranded DNA. This step is called annealation. Temperature of this step depends on the primers and is usually 5 degree C below their melting temperature. Wrong temperature at this step causes primer not to bind with DNA template or binding at random. Time of this step is 1-2 minute/s.

3rd step- After annealation, DNA polymerase has to fill the missing strands. DNA polymerase binds at annealed primer and works its way along the DNA fragment. This step is called elongation. Temperature of this step depends on DNA polymerase. However, time of this step depends both on the DNA polymerase itself and the length of DNA fragment to be elongated. Usually by the rule of thumb, the time of this step is 1 minute for every 1,000 bp.

The PCR product is identified by its size using Agarose gel electrophoresis. The sixe of PCR product is determined by comparing it with DNA ladder.

Uses of PCR
Genetic fingerprinting
Detection of hereditary disease
Cloning of genes
Analysis of ancient DNA
Paternity testing
Genotyping of specific mutation
Mutagenesis
Comparison of gene expression

Genetic fingerprinting is a forensic technique to identify a person by comparing his/her DNA with a sample e.g:- urine, semen, saliva, blood, hair from crime scene can be genetically compared to the blood of suspect.
Genetic fingerprint is unique except for identical twins
Genetic relationship can be determined by comparing two or more genetic fingerprints for paternity test
A slight variation of this technique can be used to determine evolutionary relationship between organisms.

2009-02-26T11:52:00.000-08:00

Gram positive bacteria
aerobic coccus- Staphylococcus, Streptococcus, Enterococcus
anaerobic coccus- Peptostreptococcus

aerobic / facultative anaerobic rod- Bacillus, Corynebacterium, Lactobacillus, Mycobacterium, Listeria, Nocardia
anaerobic rod- Clostridium, Actinomyces

Gram negative bacteria
aerobic coccus- Neisseria

aerobic rod- Pseudomonas
facultative anaerobic rod- Escherichis, Proteus, Klebsiella, Shigella, Salmonella, Vibrio, Haemophilus, Bordetella, Brucella, Yersinia, Pasteurella
anaerobic rod- Bacteroid, Fusobacterium
Microaerophilic rod- Campylobacter

aerobic spirochaete- Leptospira
anaerobic spirochaete- Borrelia, Treponema

About Influenza

2009-01-21T12:26:00.000-08:00

Influenza is a viral infection of birds and mammals that affects the respiratory system. The virus typically causes symptoms such as fever, sore throat and muscle pain, but severe cases can lead to pneumonia, nerve & brain damage Does Stress Damage the Brain?: Understanding Trauma-Related Disorders from a Mind-Body Perspective and even death. In the developed world, individuals at high risk of contracting influenza are usually vaccinated but as different strains of the virus mutate (a phenomenon known as ‘antigenic drift’ Genetic Drift: Genetic drift. Population bottleneck, Founder effect, Allopatric speciation, Antigenic drift, Small population size, Hardy¿Weinberg principle, ... theory of molecular evolution, Ronald Fisher), vaccines from one year may be ineffective the next, so there is a constant need for evolving, novel therapies to be developed. The virus spreads around the world in seasonal epidemics. In a typical year there are between three and five million cases of severe illness and up to half a million deaths globally. The cost of influenza in the US is over $10billion a year in lost productivity and associated medical treatment. Currently the H5N1 strain of avian influenza Avian Influenza H5N1 Strain Virus Chicken Fowl Photographic Poster Print, 18x24 poses the greatest global threat, and a pandemic is projected to cost hundreds of billions of dollars.

Research Article

2009-01-13T13:00:00.000-08:00

Journal of Nepal Paediatric Society, July-December 2008, p. 45-48, Vol 28, Issue 2
ISSN 1990-7974 (Print)
ISSN 1990-7982 (Online)

Distribution of serotypes and antimicrobial resistance of Streptococcus pneumoniae in a children's hospital in Nepal

Sherchand JB1, Joshi AR2, Gauchan P3, Amatya J4
1Jeevan Bdr Sherchand, MSc Trop. Med. PhD (U.K.); Professor, Dept of Microbiology and Chief of Health Research Laboratory, 2Ashish Raj Joshi (MSc Medical Microbiology); Kathmandu College of Science and Technology, Kalimati, 3Punita Gauchan (MSc Medical Microbiology)Research Officer, Tribhuvan University Institute of Medicine, Health Research Laboratory, Department of Clinical Microbiology, Maharajgunj, Kathmandu, Nepal, 4Jyoti Amatya (MSc Medical Microbiology), Assistant Professor in Microbiology, Kathmandu College of Science and Technology, Kalimati, Nepal.

Introduction: Streptococcus pneumoniae in low number is a part of normal nasopharyngeal and oropharyngeal flora of many healthy persons and also children, which generally remains harmless unless provoked by viral infections such as common cold, influenza etc. In this situation, pneumococcus is secondary pathogen but may be primary pathogen in immunocompromised people. Bacterial colonization of nasopharynx starts immediately after birth without development of disease. Objectices: The study was conducted to determine the prevalence of nasopharyngeal colonization with S pneumoniae, to determine their antibiotic susceptibility pattern and to determine distribution of different serotypes. Methods: Hospital based prospective study was conducted from February 2007 to September 2007. All the specimens were inoculated into 7% sheep blood agar and incubated in 5-10% CO2 atmosphere at 37*C for 24 hours. S pneumoniae was identified by colony morphology, Gram's stain, optochin susceptibility test and bile solubility test. Antibiotic susceptibility test was performed by modified Kirby-Bauer disc diffusion method. The in vitro susceptibility of the Oxacillin resistant isolates to Penicillin was determined by the E-test. Serotypes were determined by bactetrial co-agglutination using the Pneumotest Kit (Statens Serum Institut, Denmark) with 12 pooled antisera. Results: In the study, 34.6% of the children were found to be nasopharyngeal carriers of S pnemoniae among which 50.8% were male and 49.2% were female. Cephotaxime (100%), Chloramphenicol (100%) and Erythromycin (98.5%) were most effective antibiotic against S penumoniae and the least effective was Cotrimoxazole (60%). 15.4% were found to be resistant to Oxacillin. On performning E-test of Oxacillin resistant strains against Penicillin, all were found to be susceptible to Penicillin. The isolated strains were found to belong to 16 different serotypes whereas 8% were Non-typeable. Conclusion: Carriage rate is similar both in male and female. Penicillin resistance has not arisen in S pneumoniae isolated from nasopharynx which is causing problem world wide.

Key words: Children, Nasopharyngeal swab, S pneumoniae, Serotype, E-test
_________________________________________________________________

Full text (PDF):Journal of Nepal Paediatric Society

Search for genome "dark matter"

2008-12-03T12:47:00.000-08:00

The search for genome 'dark matter' moves closer
The multi-million dollar 1000 Genomes project (The Human Genome Project: Deciphering the Blueprint of Heredity) is set to be finished in a year.
Brendan Maher
The same but different. The 1000 Genomes project aims to catalogue human genetic variation.Punchstock
An almost complete catalogue of human genetic variation could be available by the end of 2009, thanks to a massive genome sequencing project that includes academic and industrial partners around the world.
Announcing completion of the pilot phase of the 1000 Genomes project, the project's co-chair David Altshuler said last week that it has already successfully catalogued 3.8 trillion bases of sequence — approximately a thousand times the number found in a single human genome. Speaking at the annual meeting for the American Society of Human Genetics in Philadelphia, Pennsylvania, Altshuler predicated that the data should be deposited in GenBank, the US National Institutes of Health database for genetic sequences, within the next two months. But that's only around a tenth of the total amount of data the project aims to rack up by the time it has finished.
"One thing we're good at is having ambitious goals," said Alan Guttmacher, interim director of the US National Human Genome Research Institute (NHGRI), one of the organizations funding the project — the final cost of which could reach US$50 million.

Variations on a theme
The sequencing initiative is a direct descendant of efforts to sequence the human genome that started in the 1990s. Soon after the announcement of the genome's first draft in 2000, a drive to map all common genetic variations between people began. This effort, known as the International HapMap Project, produced a reference guide of hundreds of millions of single-letter differences among people, which could be used to quickly compare genomes without directly sequencing them. Versions of this map have been used in genome-wide association studies during recent years to find genetic variants that are associated with common diseases, and could point to ways of predicting or even treating those diseases.
But the HapMap details only the most common genetic variants — those that occur in more than 1 in 20 people — and contains little information on rare single nucleotide polymorphisms (SNPs) or on so-called structural variants, such as large block deletions or duplications of gene sequence, which seem to be important in some diseases.
This is where 1000 Genomes comes in, says Altshuler, who is also a professor of genetics and medicine at Harvard Medical School in Boston, Massachusetts. "Next-generation sequencing makes it possible to examine a different part of the allele spectrum," he said. By fully sequencing some 1,200 people from various ethnic groups around the world and looking at parent–child trios alongside data from other sequencing projects, 1000 Genomes hopes to capture rarer genetic variations — namely, those that occur in fewer than 5% and more than 1% of people and some that occur at even smaller frequencies. The work comparing parents and their children could help scientists to get better estimates of the individual mutation rate from generation to generation. "We'll get an unparalleled view of human genetic variation," says Richard Durbin of the Wellcome Trust Sanger Institute in Cambridge, UK, and the other co-chair of 1000 Genomes.

Getting personal
The 1000 Genomes project will contain no detailed demographic or medical information about the people being sequenced so that data can be shared without the need for complicated consent procedures. Meanwhile, another major sequencing effort — the Personal Genome Project, headed by George Church of Harvard Medical School — aims to provide full sequences with medical and personal information for up to 100,000 subjects. Although its goals are less centred on uncovering variation, the Personal Genome Project, together with 1000 Genomes and several other projects looking at genetic variation, will significantly increase the amount of available DNA data for analysis.
The pilot phase of the 1000 Genomes project, which sequenced more than 180 individuals, has identified 4 million SNPs, 22% of which seem to be previously undiscovered. These data will be released in December and January, and quarterly releases are expected throughout 2009 up to the completion of the data-collection phase at the end of next year.
But the near-petabyte levels of data to be collected (by some estimates) pose significant challenges for storage and accessibility, as well as the analysis and usability of the data, says David Haussler, who leads the genome bioinformatics group at the University of California, Santa Cruz. In a nod to this need, the NHGRI announced this month that it will make up to $14 million available during the next two years for data handling and analysis for the project.

In search of 'dark matter'
Once a better catalogue of variation is complete, it could be used to power the next generation of genome-wide association studies to understand disease, potentially filling in some of the so-called missing - the genetic markers for traits or diseases that current association studies have been unable to find. These missing genetic variants have been called the genome's 'dark matter'. But some believe that the rare variants that 1000 Genomes aims to turn up may not provide useful information about disease.

"1000 Genomes will be hugely useful for growing the technology to generate and analyse sequence data," says David Goldstein of Duke University in Durham, North Carolina, adding "But in terms of a catalogue of the variants most important to human biology and disease, it's less clear how important it will be." Goldstein advocates sequencing people with extreme presentations of disease to understand more about common disease pathways.
Altshuler disagrees with Goldstein but is also cautious. "None of us imagines that we will explain 100% of disease heritability when this is finished, nor will there be drugs in the clinic immediately."
Geneticists, however, are excited about the prospect of exploring DNA's dark matter in a year's time. "I don't think it's going to be dark matter for too long," said David Valle, a clinical geneticist at Johns Hopkins University School of Medicine in Baltimore, Maryland. "When the light comes, I think we're going to find some interesting biology."

Collection of Title of Dissertation

2008-12-01T14:37:00.000-08:00

A Comprehensive Collection of Title of Dissertations Submitted by Students of M. Sc. Microbiology, Tribhuvan University till 2004 A.D

1. Microbial quality of fruits of Kathmandu Valley and their utilization in wine making and upgrading protein contents of fruits’ peels by using Aspergillus niger, Trichoderma reesei andPenicillium spp. By: RajanPrasad Adhikari

2. Study of Campylobacter in diarrhoeal and non-diarrhoeal Nepalese children and detection of Rotavirus in diarrhoeal children. By: Bidya Shrestha

3. Bacteriological investigation on ice-cream of Kathmandu Valley. By: Anjana Maharjan

4. Study on the water pollution of Ranipokhari and use of fish culture as a biological control of pond pollution. By: Anjana Shrestha

5. Study of microbiology and chemistry of Kinema. By: Kedar G.C.

6. Study of physical composition and bacteriological analysis of solid waste of Kathmandy city. By: Shova Shrestha

7. Isolation and characterization of thermophilic and amylase positive bacteria from hot spring of Nepal. By: Dwij Raj Bhatta

8. Biotyping of coagulase negative staphylococci (CONS). By: Predeep Kumar Shah

9. Bacteriological study of food and water of Pode community of Kirtipur. By: Pearl Banmali

10. Epidemiology and microbiology of lower respiratory tract infection among patients in Nepal. By: Bimmi Shrestha

11. Bacteriological study of chicken and buff meat of Kathmandu Valley. By: Gyanendra Bdr. Karki

12. Preliminary survey of dominant bacterial flora of indoor air of Kathmandu. By: Indu Bikram Joshi

13. Proteolytic activities of mesophilic bacteria. By: Anjuman Shrestha

14. Study of the lipolytic activities of fungi isolated from different oil mill areas. By: Sangita Shakya

15. Prevalence of bacteriuria and UTI in Nepali women. By: Prakash Ghimire

16. The study of antimicrobial resistance Escherichia coli. By: Dev K Ranjit

17. Study of solid waste of Kathmandu Valley and its impact on Kathmandu. By: Buddhi Pudasaini

18. Microbiology of wound infection, a hospital based study. By: Moti Lal Shrestha

19. Bacteriological profile of bacteremia and septicemia among patients visiting Patan Hospital. By: Durga Ghimire

20. Bacteriological study of cheese of Kathmandu city. By: Ira Tuladhar

21. Serological analysis of Escherichia coli isolated from various clinical specimens with special interest in gastroenteritis. By: Bishwakala Aryal

22. Microbiology of wound infection at Tribhuvan University Teaching Hospital. By: Sabina Dangol

23. A research on integrated fish culture utilizing human wastes in Nepal. By: Rabindra Acharya

24. Bacteriological study of ice-cream, butter and Raspherry of Kathmandu city. By: Pradipata Udash

25. Improvement of nutritional value of soybean by fermentation using Aspergillus oryzae. By: Pravin Malla Shrestha

26. Microbiological study of paper industries influent. By: Amod K. Pokherel

27. Screening of thermophiles from hot spring of Nepal for thermostable proteases. By: Binesh Shrestha

28. The study on microflora of fish pond water and fish intestine. By: Kushmabati Shrestha

29. HACCP module for traditional meat based street foods of Nepal. By: Lisha Joshi

30. Microbiology of urinary tract infection: a hospital based study. By: Sagarika Manandhar

31. Isolation of pectolytic microorganisms from citrus fruits and characterization of their pectic enzymes. By: Sarita Manandhar

32. Fermented soybean, a possible replacer of fish meal. By: Rashmila Prajapati

33. Isolation of Bacillus thuringiensis from soil of Nepal and its insect toxicity. By: Rina Pradhan

34. Bacteriological study of fresh vegetables of Kathmandu Valley. By: Paru Joshi

35. Isolation of Salmonella spp from blood and study of its antibiotic sensitivity pattern. By: Basudha Shrestha

36. Study of different diagnostic methods and prevalence of pulmonary tuberculosis among Nepalese population. By: Chandra Prakash Bhatta

37. Hazard Analysis Critical Control Point process in milk chain. By: Deen B. Bhatta

38. Studies on amylolytic activity during solid state fermentation of Murcha, a traditional yeast starter of Nepal. By: Gyanendra Ghimire

39. Bacteriological study of water and its treatment using plant product. By: Manoj Thapa

40. Serological survey of Hepatitis B surface antigen among the healthy Nepalese males. By: Kishor Manandhar

41. Microbiological study of body fluid. By: Sarala Joshi

42. Fermented soybean suitable protein source in fish diet in relation to its enzyme system. By: Rakesh Kumar Jha

43. Study on beta lactamase activity by microbiological and biochemical methods inStaphylococcus aureus isolated from healthy nasal carriers and hospital isolates. By: Ira Shrestha

44. Study of aetiology of acute diarrhea with special different hospitals. By: Chandana Gurung

45. Microbial analysis of burn injuries at burn unit of different hospitals. By: Manju Shree Shakya

46. Study of air microflora of Kathmandu Valley and its seasonal and locational variation. By: Babu K. Sharma Kuikel

47. Microbiology and chemical analysis of food beverages (alcoholic and non-alcoholic) at Kathmandu Valley. By: Bikash Pandey

48. Nutritional improvement of soybean by fermentation for its possible use in feed for developing state of carp family. By: Rajeev Mani Nepal

49. Bacteriological analysis of fish and its environment and enzymatic activities of fish isolates. By: Puspha Man Shrestha

50. Isolation of antibiotic resistant enteric bacteria from community ponds and their antibiotic transfer mechanism in such environment. By: Kalpana K.C.

51. Optimization of nutrient conditions for thermostable protease production. By: Sushil Man Singh Pradhan

52. Hazard analysis critical control point (HACCP) process of cheese manufacturing in Nepal. By: Rishi Prakash Niraula

53. Study on industrial effluent and its biological treatment using LEMNA species. By: Binod Lekhak

54. Characterization and optimization of alpha amylase produced. By: Sampurna S. Dangol

55. Microbiology of burn wound in children at Kanti Children’s Hospital. By: Leela Shrestha

56. Prevalence of urinary tract infection on children. By: Kirtika Gautam

57. Studies on mesophilic and thermophilic microorganisms commonly found in compost piles of Kathmandu Valley. By: Rumu Amatya

58. An epidemiological study of antibiotic resistant enteric bacteria in sub-community of Kathmandu Valley. y: Bishnu Raj Tiwari

59. Microbiology of oral cavity with special interest to beta haemolytic Streptococcus. By: Anjana Shakya

60. Characterization of E coli isolated from urinary tract infected patients. By: Kiran Shah

61. Study of causative organisms from pus sample and its antibiotic sensitivity pattern. By: Keshab Parajuli

62. Study of antimicrobial properties of Punica granatum linn By: Luna Bhatta

63. Assessment of ground water quality and study of antibiotic resistance and oligodynamic action against some isolated enteric bacteria. By: Makhan Maharjan

64. Antibacterial activities of actinomycetes isolated from soils of Kathmandu Valley. By: Reshma Tamrakar

65. Impact of effluents on rivers and reduction of biochemical oxygen demand usingCladosporium oxysporium. By: Sunil Manandhar

66. Cervicitis and cancer of cervix in Nepal. By: Archana Shrestha

67. A prospective study on bacteriology of lower respiratory tract infection among the patients visiting T.U. Teaching Hospital, Kathmandu. By: Kaushal Joshi

68. Study on urinary tract infection and cancer of urinary bladder. By: Jyoti Amatya

69. Infection of foot ulcers in leprosy patients. By: Krishna Lal Kandel

70. A prospective study on bacteriology of wound infection among inpatient at Bir Hospital (a hospital based study). By: Archana Katuwal

71. A prospective study of etiological agents causing infective endocarditis and related bacteremic and septicaemic cases among patients visiting Bir Hospital. By: Anjali Tibrewal

72. Prospective study on aetiology of childhood diarrhea based on clinical features and laboratory investigation. By: Hirdaya Ratna Shakya

73. Seroprevalence of Hepatitis B and Hepatitis C infection among blood donor in Kathmandu Valley. By: Monika Joshi

74. Utilization of fruit wastes for the production of citric acid via fermentation by usingAspergillus niger. By: Pushpa Raj Dahal

75. Utilization of tea wastes as a substrate for microbial protein production. By: Buddhi Sagar Ghimire

76. Production of aflatoxin by Aspergillus flavus isolated from different edible food stuffs of Kathmandu. By: Rupa Acharya

77. Antibacterial activity of actinomycetes isolated from various geographical region of Nepal and characterization of their antibacterial agents. By: Deepak Singh

78. A prospective study of urinary tract infection based on culture and direct microscopy of urine along with the antibiotic sensitivity test of urinary pathogens. By: Bijaya Kumar Dhakal

79. Insecticidal activities and immunology of delta endotoxins of Bacillus thuringiensis isolated from insect samples of Nepal. By: Krishna Pd. Subedi

80. Preliminary test of bacteriiocins from Pseudomonas spp isolated from potato. By: Roshana Joshi

81. Isolation, screening, identification and selection of best fermentative yeast from Murcha sample. By: Sandesh Regmi

82. Prevalence of acute diarrhoeal episodes in Kathmandu Valley during 1997. By: Aarati Karki

83. The isolation and identification of antibiotic producing bacteria in the compost samples of Kathmandu Valley. By: Pallavi Sthapit

84. Studies on effect of pesticides on soil inhabiting bacteria of pesticide applied cultivated fields of Kathmandu Valley. By: Shaila Basnyat

85. A prospective study on bacteriology of wound infection at T.U. Teaching Hospital. By: Palpasa Tuladhar

86. Study of Methicillin resistant Staphylococcus aureus (MRSA) isolated from different clinical samples. By: Reena Lamichhane

87. Fermentation of grape juice by using brewing yeast isolated from Nepalese starter Murcha. By: Chenu Gangal

88. Efficacy of alcohol fermentation of Hordeum vulgare (naked barley) from traditional Murcha. By: Leena Rajbhandari

89. Antibacterial activity of natural honey: a preliminary study. By: Sanchita Sapkota

90. Drug resistant enteric bacteria in poultry samples of Kathmandu Valley and their epidemiological study by plasmid profiling. By: Thakur Pd. Paude.

91. Screening of aflatoxin producing Aspergillus flavus isolated from maize and study on their growth suppression by various chemical agent. By: Harish C Shrestha

92. A prospective study on aetiology of bacteraemia, septicaemia at Tribhuvan University Teaching Hospital. By: Nawa Raj Banjade

93. A prospective study on aetiological agents of diarrhoeal disease in children in relation to parasites and to determine the antibiotic sensitivity pattern of isolates. By: Anand Bd. Chand

94. A study on sexually transmitted infections among the patients visiting at Tribhuvan University Teaching Hospital. By: Binita Panta

95. A study on diarrhea in children in relation to behavioral and environmental factors. By: Sujan Piya

96. Studies on role of exopolysaccharide of Xanthomonas campestris PV.Campestris, isolated from cabbage seeds, in pathogenesis and correlation of exopolysaccharide in pathogenicity on host plants. By: Dev Raj Joshi

97. Prevalence of multi drug resistant enteric bacterial pathogens in diarrhoeal patients of Kathmandu and study of their relatedness by plasmid profiling. By: Abhignya Subedi

98. Study on relationship between the infection of Helicobacter pylori and Epstein Barr Virus and the carcinogenesis of the gastric cancer. By: Priyamvada Paudyal

99. A prospective study on antibiotic sensitivity profiles of the organisms associated with clinical infections among the patients attending T.U. Teaching Hospital: a hospital based study. By: Chandra Kala Rai

100. Antibiotic resistant Vibrio cholerae isolated from Kathmandu Valley and characterization of the isolates by biotyping and serotyping. By: Arishma Rajkarnikar

101. Microbiological and chemical analysis of mineral water sold in the Kathmandu Valley. By: Shiva Raj Pohkare.l

102. Screening and evaluation of the antimicrobial activity of some medicinal plants of Nepal and isolation of pure antimicrobial compound from Bauhinia variegatn. By: Naba Raj Pokhrel

103. Microbiology study of street fried foods and isolation and identification of some microorganisms of public health importance. By: Pankaj Acharya

104. Microbiological study of raw meat of Kathmandu Valley with public health and veterinary importance and serological study of the isolated Salmonelas spp. By: Purushotam Prasai

105. Serodiagnosis of syphilis among clinically suspected patients visiting Bir Hospital and the risk of HIV and Hepatitis B infection among syphilitic patients. By: Sunita Pokhrel

106. Bacterial analysis of street food in relation to child health. By: MunMun K.C.

107. Immunodiagnostic for tuberculosis. By: Bhupesh Khadka

108. Antimicrobial activity of essential oils of some common spices. By: Sapan Sharma

109. Study on viruses in relation with skin cancer among Nepalese people. By: Rajindra Pd. Aryal

110. Study on cytokine (interferon-gammee) responses to skin test antigens of leprosy. By: Parmeshwar N. Amatya

111. Bacteriology of ear discharges. By: Charu Aryal

112. Study of solar disinfection of drinking water. By: Pratap Karki

113. A study of severe malaria in relation to HIV and syphilis among patients visiting Bheri Zonal Hospital. By: Prakriti Raj Kandel

114. Study of prevalence of Helicobacter pylori in gastroduodenal diseases and evaluation of antibiotic sensitivity pattern of the isolates. By: Suresh Subedi

115. Monitoring of liver and renal function among human immunodeficiency virus positive individuals. By: Abhilasha Karki

116. Study on bacterial flora in blood specimen collected from hospitalized and out patients services of Tribhuvan University Teaching Hospital. By: Rupa Shakya

117. Sero diagnosis of Japanese encephalitis and malaria and an assessment of public health awareness about the above (a study diseases confined within Bheri Zonal Hospital). By: Prerana Bajracharya

118. Study of physio-chemical and bactgeriological parameters of Bagmati river and treatment of polluted water using Cladosporium resinae. By: Prakash Paudyal

119. Prevalence of tuberculosis among the suspected patients visiting Tribhuvan University Teaching Hospital and their antimicrobial resistance pattern. By: Ganga G.C

120. Study of indoor Vs outdoor air microflora and its relation to PM7.07 By: Arjun Thapa

121. Air quality assessment of brick kiln area. By: Giri Raj Dahal

122. Study of microflora of vermicompost and its antagonistic activity against plant pathogenic bacteria. By: Shila Bhattarai

123. Determination of antibiotic resistant Gram negative urinary pathogens in pediatric patient at Kanti Children’s Hospital. By: Safala Dhital

124. Prevalence of common bacterial pathogens in different clinical samples submitted at Tribhuvan University Teaching Hospital and their antibiotic sensitivity test profiles. By: Rama Dhungel

125. Screening and evaluation of in vitro antimicrobial activity of medicinal plants of Nepal. By: Mahesh N. Baidya

126. Enumeration and isolation of pesticide degrading bacteria from different soil samples of Kathmandu Valley and study on transrerability of degradative plasmid from Pseudomonas putida isolates into E coli. By: Anju Sharma

127. Study of Hazard analysis critical control points (HACCP) system in sausage production plants. By: Buddhi K Shrestha

128. Study of microbial flora present in the conjunctiva of the cataract patients before and after the use of betadine solution and its antibiotic sensitivity pattern. By: Lata Ghimire

129. Study of microbiological and chemical quality of fermented milk (DAHI) of Kathmandu Valley. By: Sushama Sharma

130. Distribution of citrus tristeza virus (CTV) in various regions in Nepal and development of virus free plantlets by meristem culture. By: Chaman Ranjit

131. Antibiotic sensitivity profile of E coli, Klebsiella spp and Pseudomonas spp of patients visiting TUTH, Kathmandu. By: Tarani Prasad Paneru

132. Study of air, water and wound infection in different wards of T.U. Teaching Hospital. By: Megh Raj Banjara

133. Insecticidal activities of Bacillus thuringiensis against Culex quinquefasciatus andSpodoptera litura. By: Sangita Bhattarai

134. Study of meningitis in patients visiting Tribhuvan University Teaching Hospital. By: Kiran Babu Tiwari

135. Microbial digestion of vegetables and kitchen wastes for biogas production. By: Nawa Raj Dhakal

136. Development of IND-ELISA for actinomycetes and study of serological relationship. By: Yogan Khatri

137. Assessment of drinking water quality supplied by Nepal water supply corporation, Sundarighat and identification, antibiotic sensitivity pattern and serotyping of isolated E coli. By: Supriti Shrestha

138. Pattern of microbial flora among the visitors and the environment of intensive care unit (ICU), Tribhuvan University Teaching Hospital. By: Sriju Sharma

139. Prevalence and antibiotic sensitivity pattern of Methicillin resistant S aureus (MRSA) in Bir Hospital. By: Rajita Rajbhandari

140. Salmonella serotyping and drug susceptibility pattern from envirionment and clinical samples of urban Nepal. By:Aashish Poudyal

141. Bacteriological study of upper respiratory tract infection inpediatric patients at Kanti Children’s Hospital. By: Anima Shrestha

142. A hospital based study of urinary tract infection among women visiting antenatal clinic of Tribhuvan University Teaching Hospital. By: Rupa Pandey

143. Drinking water quality assessment of Kathmandu Valley and antibacterial property of enteric bacteria isolated. By: Tista Prasai

144. Prevalence of beta haemolytic streptococci in throat of school children and its antibiotic sensitivity pattern. By: Deepak Acharya

145. Study on nasal carriage of Staphylococcus aureus among the post operative ward visitors, staff and patients of T. U. Teaching Hospital with drug sensitivity pattern. By: Khadga B. Shah

146. Optimization and use of polymerase chain reaction for the diagnosis of tuberculosis and leprosy. By: Bishwa Raj Sapkota

147. Prevalence of bacterial infection in acute hepatitis in Nepal. By: Durga Shrestha

148. Quality control in tuberculosis smear microscopy. By: Sneha Bam

149. Study of the prevalence of Campylobacter in raw meat and drinking water in water corporation of Kathmandu and possible research for Shigella spp. By: Ita Bhattarai

150. Tubersulosis and human immuno deficiency virus co-infection in united mission hospital, Tansen, Nepal. By: Janak R. Dhungana

151. A prospective study on acute group A streptococcal pharyngitis and its delayed sequelae on school children of Kathmandu Valley, Nepal By: Binod Pd. Pathak

152. Study of the factors associated with enteric parasitic infection among school children in a rural village setting in Kathmandu Valley, Nepal. By: Diyo Ram Rai

153. Anti tuberculosis treatment resistant in pulmonary tuberculosis patients visiting German Nepal tuberculosis project, Kalimati, Kathmandu. By: Narayan Raj Bhattarai

154. Relative study of enteropathogens (parasites and bacteria) in gastroenteritis and its predisposing factors in TUTH. By: Keshav Rai

155. Study of ambient air micro flora of Kathmandu Valley and its relation to particulate matters. By: Rajendra Pd. Subedi

156. Prevalence of enteric parasites in HIV/AIDS patients of Nepal. By: Darshan Sapkota

157. Prevalence of lymphatic filariasis in Dhanusha district of Nepal, By: Nagendra Prasad Yadav

158. Study on the prevalence of multiple drug resistant Sammonella spp in poultry birds. By: Madhusudan Pandey

159. Microbial contamination of the contact lens and its care system in the patients visiting BPK lion center for ophthalmic studies, Maharajgunj, Kathmandu. By: Pallavi Gurung

160. Evaluation of nitrate test in detecting urinary tract infection conducted at TUTH. By: Sushil Chandra Regmi

161. Microbial colonization of maternal genital tract and its relationship to onset of early neonatal sepsis. By: Salina Gaire

162. Studies on the antibacterial activity of actinomycetes isolated from Khumbu region of Nepal. By: Bhagwati Pantdey

163. Carriage pattern of S sureus in healthy school children. By: Sachindra R. Joshi

164. Prevalence of urinary tract infection in diabetic patients. By: Preeti Gautam

165. Comparative study of tuberculosis test Ziehl Neelsen staining and culture in the diagnosis of tuberculosis. By: Pratap Shahi

166. Superficial fungal infection and awareness status among the patients visiting dermatology outpatients department of TUTH. By: Niraja Thapa

167. Modulation of whole blood imme to phenolic glycolipid (PGTD of M. Leprae). By: Suraj Dhungel

168. Comparative evaluation of different staining techniques for the diagnosis of tuberculosis lymphadenitis. By: Smritee Pohharel

169. Evaluation of antimicrobial resistance status in Kirtipur community bacterial isolates. By: Manoj Ghimire

170. Air quality assessment of Kathmandu Valley. By: Pukar Acharya

171. Production and characterijation of the antimicrobial substances from Bacillus species. By: Dipak Adhikari

172. Characterization of proteases from Bacillus species producing antimicrobial substances. By: Bharak Khatiwada

Find here more Title of Dissertation (that were later submitted)

Source: Microbiological Abstracts (Revised edition 2004). Published by MISAN, Central Department of microbiology, Tribhuvan University, Kirtipur, Kathmandu, Nepal.

Biological Sciences

PCR (Polymerase Chain Reaction)

CRISPRCas9

Antibody (Immunoglobulin)

CORONAVIRUS

Dengue Fever

FASTER WAY TO PRODUCE SPECIFIC HUMAN ANTIBODIES USING NANOPARTICLES

BACTERIOPHAGES: SMALL THINGS CONSIDERED

These "Indestructible" Animals Would Survive a Planet-Wide Apocalypse

Discoverer of penicillin Alexander Fleming warned against its overuse and the risk of resistant microorganisms as early as 1945, in his Nobel Prize lecture

Yoshinori Ohsumi: Autophagy from begining to end

Autophagy genes are discovered by Yoshinori Ohsumi for the greatest benefit to mankind

Nobel Prize 2016 in Physiology or Medicine

The 2016 Nobel Prize in Physiology or Medicine is awarded to Yoshinori Ohsumi for his discoveries of mechanisms for autophagy which was announced on 3rd October 2016

Bacteria*Bioengineering*Storage

Collection of Title of Dissertation (Updated)

Advice for potential biology graduate students

Nobel Prize for RIBOSOME researchers

WHO backs anti-diarrhoea vaccine

WHO backs anti-diarrhoea vaccine

'Breakthrough' in malaria fight

Malaria parasites 'resist drugs'

Polymerase Chain Reaction (PCR)

About Influenza

Research Article

Search for genome "dark matter"

Collection of Title of Dissertation

BacteriaBioengineeringStorage