Biomarker for deadly pathogen identified

Washington, July 8: Scientists have discovered several biomarkers that can accurately identify a drug- resistant pathogen that infects completely healthy people, can cause blindness in one day, and even lead to flesh- eating infections and death in just a few days.

Thomas A Russo, a professor at University at Buffalo in the US, witnessed the first case of the hypervirulent Klebsiella pneumoniae seven years ago.

There is no accurate method for distinguishing the rare but increasingly common hypervirulent strain from the classical strain of K pneumoniae, which causes infections in hospital settings.

In a study, published in the Journal of Clinical Microbiology, researchers described several biomarkers that can accurately identify hypervirulent K. Pneumoniae.

“Presently, there is no commercially available test to accurately distinguish classical and hypervirulent strains. This research provides a clear roadmap as to how a company can develop such a test for use in clinical laboratories. It’s sorely needed,” said Russo.

A definitive diagnostic test would not only optimise patient care but would also allow researchers to perform epidemiologic surveillance to track how frequently the hypervirulent strain causes infection and how frequently it acquires antimicrobial resistance.

While the assumption is that the pathogen spreads from person to person through food and water, the mode of transmission is unknown.

Both strains of K pneumoniae can be deadly, but the classical strain is more likely to infect patients with underlying disease, or who are immune- compromised and hospitalised.

By contrast, the hypervirulent strain can infect healthy, young people in the community, causing sudden, lifethreatening complications, ranging from liver or brain abscesses to flesh- eating infections.

While it is currently less likely to be antibiotic resistant, these strains continue to evolve. Classical strains are more likely to be antimicrobial resistant.

“What’s increasingly concerning is the growing number of reports that describe strains of hypervirulent K pneumoniae that are antimicrobial resistant,” said Russo.

“A bug that’s both hypervirulent and challenging to treat is a bad combination,” he said.

Since clinical laboratories have no test to detect the hypervirulent strain, it’s difficult to properly diagnose it.

The so- called string test, used in some cases to distinguish the classical and hypervirulent strains, is not consistently accurate.