Friday, 4 November 2016

Antibiotic resistance linked with exposure to chlorhexidine


Klebsiella pneumoniae bacteria exposed to chlorhexidine-containing disinfectants can become resistant to colistin, a last resort antibiotic often used against multidrug resistant pathogens. This is the first study to link exposure to chlorhexidine with resistance to colistin in this clinically important pathogen.

In the study, the investigators tested the hypothesis that K. pneumoniae could survive exposure to increased concentrations of chlohexidine, and that these exposures might cause resistance to commonly used antibiotics. They selected specific strains of K. pneumoniae that were representative of isolates routinely found in the clinic.

Chlorhexidine is a common ingredient in a number of disinfectants used widely in the home and in healthcare settings, where it is a critical part of many infection control practices.

While some strains died on exposure, others were able to survive at much higher concentrations of chlorhexidine than their parental strains. Some also gained resistance to colistin. The investigators also found gene mutations in the exposed K. pneumoniae that conferred resistance to both compounds.

For further details, see:

Matthew E Wand, Lucy J Bock, Laura C Bonney, J Mark Sutton. Mechanisms of increased resistance to chlorhexidine and cross-resistance to colistin following exposure of Klebsiella pneumoniae clinical isolates to chlorhexidine. Antimicrobial Agents and Chemotherapy, 2016; AAC.01162-16 DOI: 10.1128/AAC.01162-16

Posted by Dr. Tim Sandle