Variable chlorhexidine MICs across Klebsiella species from a single facility

ABSTRACT We assessed in vitro chlorhexidine minimal inhibitory concentrations (MICs) across Klebsiella species from a hospital with widespread chlorhexidine use. Isolates underwent MIC testing and whole genome sequencing. Species showed varying resistance, with Klebsiella quasipneumoniae having the highest MICs. There was no clear link to acquired resistance, but some species had more chromosomal efflux pumps. Differences in chlorhexidine MICs between species highlight the role that biocides could have in shaping microbial populations in the hospital environment.