How Bacteria Slips By Antibiotics

(Ivanhoe Newswire) – Antibiotics are often the best treatment for bacterial illnesses, but sometimes the drugs will not completely cure the problem. The bacteria slipping by antibiotics can be concerning, especially for anyone with certain diseases. However, thanks to an international study we can better understand how some bacteria survive antibiotics and hopefully this knowledge will lead to better treatments as well.

Researchers from Japan and France set out to find how bacteria can elude antibiotics by looking at Mycobacterium smegmatis cells, a bacterium similar to the one that causes tuberculosis, in microfluidic cultures. The M. smegmatis cultures were then treated with a common antibiotic called isoniazid.

Through analyzing the cultures, the study found that bacteria escaped isoniazid because of random pulses of an enzyme called KatG which activates the antibiotic.

In between pulses of the enzyme it was extremely difficult for the antibiotic to be activated, leading the bacteria to have a higher chance of survival. So, the important component in whether or not the bacteria can continue to survive after antibiotics are administered depends on how much KatG it produces.

Since the study only looked at the M. smegmatis bacteria, researchers cannot be sure enzyme production is the determining factor for all bacteria.

"At present we can only speculate as to whether the same or similar mechanisms exist in other bacterial species, although we think this is likely," study researcher Yuichi Wakamoto from the University of Tokyo was quoted as saying.

Although further research needs to be done, this knowledge could inform researchers in the future who want to develop drugs for bacterial strains that are difficult to treat.

These results also prove that the commonly help belief that non-dividing "persister cells" are responsible for bacteria’s survival during drug treatment.

"Our Science paper provides clear experimental proof that other mechanisms of persistence also exist," Neeraj Dhar of the Swiss Federal Institute of Technology in Lausanne was quoted as saying.

Source: Science, January 2013