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Scientists discover tree fungus that could provide green fuel for transport
A tree fungus could provide green fuel that can be pumped directly into tanks, scientists say. The organism, found in the Patagonian rainforest, naturally produces...
2008-11-05 01:45:30
Scientists discover Patagonian diesel that grows on trees
A tree fungus could provide green fuel that can be pumped directly into vehicle tanks, US scientists say. The organism, found in the Patagonian rainforest, naturally produces...
2008-11-05 01:36:30
Antibiotic sets up roadblock to kill bacteria
INT32International/Medicine/ScienceAntibiotic sets up roadblock to kill bacteriaWashington Oct 25 IANS Scientists have edged closer to developing more effective drugs by identifying how an antibiotic sets up roadblocks to halt bacterial growth.Until now, researchers did not know the mechanism behind how the antibiotic actually killed the bacteria.For example, myxopyronin, an antibiotic, is a natural substance generated by bacteria to fend off other bacteria. It is known to have inherited the actions of an enzyme called RNA polymerase, which activates gene expression and is essential for a cell's life.Key to investigating this mechanism is the use of the powerful imaging technique X-ray crystallography, which allows researchers to see the fine details of the linkage between the antibiotic and its target, according to an Ohio State release. The study was published online in Nature."This is the first antibiotic that we know that inhibits polymerase before it even starts RNA synthesis," said Irina Artsimovitch, a co-author of the study and an associate professor of microbiology at Ohio State University.--Indo-Asian News ServiceSt/jg179 Words25101504
2008-10-25 06:03:09
Now, a safer, more effective TB vaccine for HIV-positive people
Washington, Oct 24 ANI: Scientists at University of California, Los Angeles UCLA, have developed a new vaccine for tuberculosis TB, which they claim is safer and more effective for HIV-positive people. The vaccine, which has been especially designed for HIV-positive people, may help curtail the global spread of the disease, as tuberculosis has been known as a biggest cause of death in people with HIV. "The AIDS and tuberculosis epidemics are now so intertwined in many parts of the world that we can't win the fight against one of these diseases without also taking on the other," said Dr. Marcus Horwitz, principal investigator and professor of medicine and microbiology, immunology and molecular genetics, David Geffen School of Medicine at UCLA. The current vaccine against tuberculosis, called BCG, can cause serious and even fatal disease in HIV-positive people later in life, if HIV weakens the immune system, allowing the vaccine to multiply unchecked and spread throughout the body. Aiming to solve this problem, the researchers used an innovative method to limit the number of times the new vaccine can replicate in the body -- just enough to stimulate the immune system to produce T cells to fight future infection with the tuberculosis bacillus, but not enough to overwhelm the immune system if it subsequently becomes weakened by HIV. The researchers showed that the new vaccine better protects guinea pigs from tuberculosis than the current vaccine. They also showed that the new vaccine is much safer than BCG in a severely immunocompromised animal host - mice with Severe Combined Immunodeficiency SCID mice that completely lack an immune system. The new vaccine was specifically designed to be given to HIV-positive newborns and adults whose immune systems haven't been affected much are thus capable of mounting a good immune response to the vaccine, including persons on antiretroviral therapy. For developing the new vaccine, the scientists modified the current BCG vaccine, which is a weakened form of a bacterium closely related to the one that causes tuberculosis. Thus, the researchers first made so that it would produce large amounts of a key protein of Mycobacterium tuberculosis, called mycolyl transferase, hence making the vaccine more potent and induce a stronger immune response. Them, in order to make it safer, the team altered the BCG vaccine so that it was only capable of multiplying a few times after it was injected into the body. They, thus, eliminated the vaccine's ability to acquire iron from the host; iron is an essential nutrient for the vaccine to multiply. It is believed that since iron is a key nutrient needed by all bacteria to thrive, this approach may be applicable to other live bacterial vaccines for diseases such as anthrax, tularemia and Legionnaires' disease. Now, the researchers are hoping to test the vaccine in humans. The study is published in the latest edition of the journal Infection and Immunity. ANI
2008-10-24 08:00:00
TB-bacteria linked to bone infections
Washington, Oct 18 ANI: A newly described species of bacteria related to the tuberculosis pathogen has been found to cause bone infections-a discovery that may pave the way for better diagnosis and treatment of similar infections, says a new study.Patients having some rare genetic diseases are prone to infections with Mycobacterium species, the bacteria behind tuberculosis and leprosy. The patients often suffer from recurring mycobacterial infections throughout their whole lives. Thus, researchers are trying to identify unusual species that cause disease in order to improve treatment strategies."We isolated an unknown species of bacteria from a 7 year old child who has a genetic immune defect. The infection had caused bone lesions and this is where we found the newly described bacteria," said Dr Didi Bang from Statens Serum Institut in Copenhagen, Denmark. Owing to their antibiotic resistant cell walls and immunity towards treatment, bacteria can survive attack with acids, alkalis and detergents.While the majority of mycobacterial infections can be treated with antibiotics such as clarithromycin and rifamycins, some species are becoming resistant to these antibiotics, so new drugs for treatments must be developed."Initial tests suggested we had found a Mycobacterium. By sequencing some of the bacterium's genes we showed that we had discovered an undescribed species," said Bang. Bang added: "We called the bacterium Mycobacterium arosiense. The name comes from Arosia, the Latin name of the city of Aarhus in Denmark, which is where the bacterium was first found. We showed the position of the new bacterium on the Mycobacterium family tree by sequencing genes and comparing them to related bacteria."Closely related to Mycobacterium intracellulare and Mycobacterium avium, the new pathogen leads to a lung disease similar to tuberculosis in people, especially those with weak immune systems such as HIV patients that are immunologically suppressed. It is rod-shaped and grows slowly.Bang said: "Mycobacterium arosiense can be killed by several antibiotics in the lab, including clarithromycin and rifamycins. However, resistance to fluoroquinolones and isoniazid was observed. Little knowledge is available on performing resistance tests on mycobacteria other than tuberculosis."We hope that this discovery will help doctors to diagnose similar diseases in the future and that further investigation may improve the treatment of people with similar infections."The study is published in the latest issue of the International Journal of Systematic and Evolutionary Microbiology. ANI
2008-10-18 06:00:00
How gut bacteria can cause colon cancer
Washington, Sept 22 ANI: American scientists claim to have uncovered how a common gut bacterium causes colon cancer.The researchers have found that a molecule produced by common gut bacteria Enterococcus faecalis activates signalling pathways associated with cancer cells. Unlike most gut bacteria, it can survive using two different types of metabolism: respiration and fermentation. When the bacteria use fermentation they release by-products. One of these is a kind of oxygen molecule called superoxide, which can damage DNA and may play a role in the formation of colon tumours."We wanted to investigate how colon cells respond to normal gut bacteria that can damage DNA, like E. faecalis," said Professor Mark Huycke from the Department of Veterans Affairs Medical Center in Olklahoma City, USA. "We found that superoxide from E. faecalis led to strong signalling in immune cells called macrophages. It also altered the way some cells in the gut grew and divided and even increased the productivity of genes that are associated with cancer."The team found that 42 genes in epithelial cells in the gut are involved in the regulation of the cell cycle, cell death and signalling based on the unique metabolism of E. faecalis. The researchers say that their findings suggest that cells of the lining of the colon are rapidly affected when E. faecalis switches to fermentation. It also indicates that E. faecalis may have developed novel mechanisms to encourage colon cells to turn cancerous, they add."Our findings are among the first to explore mechanisms by which normal gut bacteria damage DNA and alter gene regulation in the colon that might lead to cancer," said Huycke.The study is published in the October issue of the Journal of Medical Microbiology. ANI
2008-09-22 04:00:00
Stanford 'microbe hunter' Stanley Falkow wins Lasker Award
For his lifetime of pioneering work in microbiology and immunology, Stanley Falkow, 74, on Saturday received the Lasker-Koshland Award for Special Achievement in Medical Science. Given once every two years, the award carries a $300,000 cash prize and is one of the nation's highest honors for medical researchers.
2008-09-14 00:05:07
Bleeding gums 'up heart attack risk'
Washington, Sept 11 ANI: Poor dental hygiene and bleeding gums can put you at an increased risk of suffering a heart attack, according to a new research.According to the study, which was presented at the Society for General Microbiology's Autumn meeting, revealed that people with poor dental hygiene and those who don't brush their teeth regularly end up with bleeding gums, which provide an entry to the bloodstream for up to 700 different types of bacteria found in our mouths. As a result, the risk of having a heart attack increases, according to microbiologists from the University of Bristol and the Royal College of Surgeons in Ireland."The mouth is probably the dirtiest place in the human body," said Dr Steve Kerrigan from the Royal College of Surgeons in Dublin, Ireland. "If you have an open blood vessel from bleeding gums, bacteria will gain entry to your bloodstream. "When bacteria get into the bloodstream they encounter tiny fragments called platelets that clot blood when you get a cut. By sticking to the platelets bacteria cause them to clot inside the blood vessel, partially blocking it. This prevents the blood flow back to the heart and we run the risk of suffering a heart attack," he said.The only treatment for this type of disease is aggressive antibiotic therapy, but with the increasing problem of multiple drug resistant bacteria, this option is becoming short lived. ANI
2008-09-11 02:00:00
Light-activated treatments may solve MRSA problems after surgery
Washington, Sept 10 ANI: Researchers from University College London, UK have suggested that using near infrared light along with killer dyes that can wipe out bacteria could effectively kill superbug problems faced by surgical patients.The study led by Dr Ghada Omar showed that 99 pct of the potentially dangerous Staphylococcus aureus bacteria in infected wounds can be killed using a green dye that releases toxic molecules when it is activated by near-infrared light.Near-infrared light is commonly used in fibre-optics and telecommunications because it passes through glass easily. The dye used, called indocyanine green, is harmless to humans and inactive in the dark. However, it gives off toxic molecules that rapidly kill the bacteria when it is triggered by the right light wavelengths."The chemicals produced when the dye is activated harm the bacteria in such a wide variety of ways that it is unlikely bacteria could ever develop resistance to the treatment," said Dr Omar. "This makes it ideal - and possibly the only option - for treating infections with multiple drug resistant bacteria, including MRSA," he added. The new light-activated antimicrobial treatment is less effective when there are low oxygen levels in the infected tissues. This is a common problem in injuries where blood systems have been damaged, or where the injury is further away from the bodies' main vascular systems. The new study showed that even with very low oxygen levels in the damaged tissues, most dangerous bacteria can still be killed using the light-activated dyes."Increasing oxygen levels in the infected tissues would maximise the killing effect", said Dr Omar. "But even with low oxygen levels a very wide range of bacteria were killed, including over 70percent of Streptococcus pyogenes," he added. The findings were reported at the Society for General Microbiology's Autumn meeting in Dublin. ANI
2008-09-10 09:02:11
Titanium work surfaces can reduce food poisoning cases
Washington, Sept 10 ANI: Food factory work surfaces coated in titanium are better than those of stainless steel, for they can cut the number of food poisoning cases every year, a new study has revealed.In the food industry, work surfaces need to be easy to clean, but wear of food contact surfaces through abrasion, cleaning and impact damage increases the surface roughness, making it quite difficult to clean the surfaces.Researchers from Manchester Metropolitan University, UK have examined the way different work surfaces harbour bacteria that could contaminate food and found that titanium coated surfaces can make it more difficult for pathogenic bacteria to attach themselves to the metal."It is important that surfaces in a hygienic environment are kept clean. Scratches may entrap micro-organisms such as Escherichia coli and protect them from being removed during cleaning. We measured scratches found on different surfaces and reproduced them in our lab. We coated the surfaces with titanium so that they all had the same chemistry and the only difference was the surface roughness," said Adele Packer from Manchester Metropolitan University. The scientists examined how bacteria are retained after cleaning to surfaces with scratches, and discovered that the shape of the bacteria affected their retentionWhile rod-shaped Listeria remained in tiny scratches less than 0.5 micrometers across, and round Staphylococcus cells stuck in scratches measuring 1 micrometer across."The results show that surface scratches retain bacteria well if they are of comparable size. The more tightly the bacteria fit in the scratches, the more difficult they are to remove during cleaning. Our findings also indicate that titanium coating may have a role in reducing the attachment of E. coli to food contact surfaces; E. coli cells attached to stainless steel much better than titanium," said Adele Packer. He added: "These results will help designers make hygienic surfaces that are easy to clean. This should help to reduce the chances of cross-contamination and cross infection."The study was presented at the Society for General Microbiology's Autumn meeting being held this week at Trinity College, Dublin. ANI
2008-09-10 06:02:07