New Study Shows How Bacteria Develop Resistance to Vancomycin

Vancomycin is a powerful, chlorine-containing antibiotic drug that often works when all other antibiotics fail. Vancomycin has saved the lives of patients suffering from serious, stubborn bacterial illnesses. Now, for the first time, researchers have uncovered how bacteria recognize and develop resistance to vancomycin.

A research team led by Dr. Gerry Wright of McMaster University identified the specific mechanism that triggers resistance to vancomycin. Researchers are optimistic that these findings will lead to the development of new antibiotics that can overcome resistance. The research, funded in part by the Canadian Institutes of Health Research and the Canada Research Chairs program, is published online in the journal Nature Chemical Biology.

“Vancomycin is the antibiotic of last resort and is only given when all other treatments fail,” said Wright, who holds the Canada Research Chair in Molecular Studies of Antibiotics and an endowed research Chair in Infection and Anti-Infective Research.

“For years it was thought that resistance would be slow to emerge since vancomycin works in an unusual way. But with the widespread use of the drug to treat infections caused by the hospital superbug MRSA, it has become a serious clinical problem.”

Most antibiotics work by inhibiting an enzyme in bacteria, but vancomycin binds to bacterial cell wall building blocks, causing a weakness in the structure of the cell wall so the cell bursts and dies. Scientists around the world have debated whether bacteria sense the drug itself to trigger resistance or whether they sense the impact it has on the cell wall of bacteria.

The researchers in this study showed that bacteria detect vancomycin itself, which triggers resistance. These findings should lead to the development of new therapies to prevent and treat antibiotic-resistant infections.

The unexpected early development of bacterial resistance to this drug points to the importance of hospitals and clinics including multiple infection barriers such as early identification of patients at high risk, hand-washing, a clean hospital environment and sound sanitation practices carried out routinely by hospital staff so as to minimize the risk of hospital/clinic acquired infection.

(Chris J. Wiant, M.P.H., Ph.D., is president and CEO of the Caring for Colorado Foundation. He is also chair of the Water Quality & Health Council.)