When Klebsiella pneumoniae bacteria are exposed to disinfectants containing chlorhexidine, the bacteria can become resistant to colistin, a last-resort antibiotic, according to a study published in Antimicrobial Agents and Chemotherapy, a journal of the American Society for Microbiology.
The study is the first ever to link chlorhexidine exposure with colistin resistance.
Researchers tested strains of K. pneumoniae typically found in healthcare and exposed them to increasing concentrations of chlorhexidine. While some strains died from the exposure, others survived and some gained resistance to colistin.
They also discovered gene mutations in some of the surviving strains that conferred resistance to both colistin and chlorhexidine.
"Chlorhexidine is a critical part of current infection control practices, and the development of increased resistance to this compound has potential implications for our ability to prevent infections during routine and emergency surgery, and during admission to hospitals," said J. Mark Sutton, PhD, the study's co-author.
"This might mean that we need to rethink how and where some types of critical disinfectants or antiseptics are used in the clinic," he said.