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Biochemistry

Scientists find ways to reverse drug resistance, a major burden in treating Tuberculosis

A recent report by the World Health Organization estimates that about two million deaths occur every year due to tuberculosis (TB). An alarming dimension to this problem is the fact that some strains of Mycobacterium tuberculosis (Mtb), the causative agent of TB, have developed resistance to some antibiotics used to kill them, leading to the emergence of ‘drug resistant TB’ and causing a global threat. Drug resistance is a way by which bacteria respond to the drug stress they face. Due to improper and irregular use of antibiotics by patients, not all bacteria may be killed, leading to the emergence of drug resistant strains that survive even when further doses of the drug are administered. Now, a team of researchers at the Indian Institute of Science, Bangalore, led by Prof. Nagasuma Chandra and Prof. Amit Singh, have explored the mechanism behind the development of resistance to a front-line anti-tubercular drug called isoniazid, used widely in the clinic.

 

Yeasts on a protein diet: Scientists decode the mechanism behind this

Many organisms, including yeast, obtain Carbon and energy from carbohydrates and Nitrogen from other nutrients like amino acids. But some types of yeast, like Pichia pastoris, can use amino acids not only as sources of Nitrogen, but also as sources of Carbon too finds a new study at the Indian Institute of Science, Bangalore. The team, consisting of Mr. Umakant Sahu and Prof. P N Rangarajan from the Department of Biochemistry, have studied the mechanism behind how P. pastoris can grow happily in a medium that does not contain glucose but only amino acids like glutamate, aspartate, proline, etc.

To Cut or Not to Cut-The Bacterial Dilemma!

Some bacteria possess an interesting ability of incorporating a new piece of DNA from the outside.This new DNA might come from its surroundings, other bacteria or even invading virus and might help in fostering genomic diversity. In fact, scientists now believe that this phenomenonis much more common than previously thought. However, incorporating a viral DNA may be harmful where the viruses utilize every opportunity to sneak into a bacterium and, hijack its machinery to replicate the viral DNA. Hence, to protect themselves, bacteria have evolved a mechanism called restriction modification system. And yet, it could work for the advantage of the bacterium sometimes to restrain this system and usher in new foreign DNA that might contribute to its own genomic diversity.

Lab Story: Understanding a Versatile Bacterium in our Stomach

People had never thought that Gastritis in the stomach was caused by a bacterium, never believed it could be, so much so that one of the two scientists Barry Marshall and Robin Warren had to drink a cupful of Helicobacter pylori culture to show that he developed gastritis! They were later awarded a noble prize for their discovery of the bacterium Helicobacter pylori and its role in gastritis and peptic ulcer.

Endosulfan induces male infertility in mice

The hotly debated and controversial pesticide – Endosulfan, is back in news again. Researchers at IISc have discovered that endosulfan causes a significant decrease in sperm count and sperm motility in mice, leading to male infertility. Besides, it also exerts damage on liver, lungs and testes.

A novel vaccine against Hepatitis C Virus customized for the Indian population

It is estimated that there are around 6 to 12 million Hepatitis C Virus (HCV) infected people in India, most of them are unaware about the infection. This virus which spreads by direct contact with the blood of infected persons can cause severe liver complications which may lead to cancer. Among many strains of the virus, HCV genotype 3a is the predominant strain of the virus found in the Indian sub-continent. The good news however is that we may soon have a vaccine against this strain of the virus.