Adaptive microbial response to low level benzalkonium chloride exposure

Publication date: Available online 31 May 2018Source: Journal of Hospital InfectionAuthor(s): Günter KampfSummaryBenzalkonium chloride (BAC) is a commonly used active agent in healthcare, e.g. in surface disinfectants, disinfectant cleaners or sometimes also in skin antiseptics. Aim of the review was to evaluate the potential of bacteria to adapt to low level BAC exposure. A maximum 4-fold MIC increase was found in most of the 57 evaluated bacterial species. A strong adaptive, mostly stable, MIC change was described in strains or isolates of Pantoea spp, Enterobacter spp., S. saprophyticus or E. coli (up to 500-fold, 300-fold, 200-fold or 100-fold, respectively). The highest MIC values after adaptation were 3,000 mg/l (S. typhimurium), 2,500 mg/l (P. aeruginosa), 1,500 mg/l (Enterobacter spp.) and 1,000 mg/l (E. coli, S. saprophyticus). Cross resistance to selected antibiotics such as ampicillin, cefotaxime or ceftazidime was found in some isolates, or to biocidal agents such as didecyldimethylammonium bromide, didecyldimethylammonium chloride, triclosan and chlorhexidine. A significant up-regulation of transporter and efflux pump genes was found in B. cepacia complex and E. coli. Adapted isolates are probably not killed anymore by disinfectants based on BAC at the recommended use concentration. The use of BAC in patient care - but also all other settings such as consumer products and households - should be critically assessed and restricted to indications with a proven heal...
Source: Journal of Hospital Infection - Category: Infectious Diseases Source Type: research