Prevalence of mutations associated with tolerance to chlorhexidine and other cationic biocides among clinical isolates.

is a frequent cause of catheter-associated urinary tract infection and often exhibits high tolerance to chlorhexidine (CHD), a biocide used widely in healthcare settings. We previously demonstrated that inactivation of the s repressor (leading to overexpression of the efflux system), truncation of the MltA-interacting protein MipA and aspects of lipopolysaccharide (LPS) structure modulate CHD susceptibility in this organism. However, the prevalence of these mechanisms among clinical isolates, the conditions under which they can be acquired and their impact on susceptibility to other cationic biocides require further study.