Researchers at the Indian Institute of Science (IISc.) have designed an anti-microbial peptide (AMP) that, researchers say, can effectively and quickly kill a notorious multidrug-resistant bacterium called Acinetobacter baumannii.

According to a press release by IISc., the bacterium tops the WHO’s list of threats that urgently need new antibiotics because it is “remarkably adept at developing drug resistance”. The release also stated that it is among the six species responsible for most infections in hospitals and health care centres.

In a new study published in Science Advances, IISc. researchers used a bioinformatics approach to design a new short protein (peptide) called Omega76 that can kill A. baumannii by breaking down its cell membrane.

Infected mice treated with Omega76 had much better survival rates. The team also found that high doses of Omega76 given for prolonged periods did not produce any toxic effects. Since it is safe and effective, it is a promising candidate for developing new antibiotics, the researchers say.

Dipshikha Chakravortty, Professor at the Department of Microbiology and Cell Biology, who was part of this research, was quoted as saying, “The significance of A. baumannii infection was not sufficiently understood earlier… It was regarded as just another bug in the environment. It has now become a major threat, especially in the intensive care units.”

The release stated that antibiotics for such infections may soon become ineffective, as resistance to even last-resort drugs such as carbapenems is on the rise.

“They are not entirely safe either; a drug called colistin, which is considered the last hope for multidrug-resistant infections, has been found to cause severe kidney damage,” said postdoctoral fellow Deepesh Nagarajan.

While standard drugs act by “blocking specific pathways or processes in bacterial cells,” bacteria can evolve to gain resistance against such drugs. Nagasuma Chandra, Professor at the Department of Biochemistry, said, “On the other hand, anti-microbial peptides (AMPs) actually punch holes in the bacterial cell membrane. The chances of drug resistance are much lower because they act by multiple ways and cause actual physical damage.”

The researchers plan to improve its design further, and explore clinical uses.

source: http://www.thehindu.com / The Hindu / Home> News> Cities> Bengaluru / by Staff Reporter / Bengaluru – July 30th, 2019