title: Reduced susceptibility of methicillin-resistant Staphylococcus aureus to cetylpyridinium chloride and chlorhexidine.
abstract: Sensitivities of 120 strains of Staphylococcus aureus to methicillin, cetylpyridinium chloride (CPC) and chlorhexidine (CH) were measured by the agar dilution technique. The MICs for CPC and CH were < or = 2 micrograms/ml in 93 and 83% of methicillin-sensitive S. aureus, respectively, and > 2 micrograms/ml in 81 and 83% of methicillin-resistant S. aureus (MRSA), respectively. Overall, the MICs for CPC and CH were 5-10 times greater in the methicillin-resistant than in the methicillin-sensitive strains (p < 0.001). The MICs for CPC and CH also predicted the relative susceptibilities of S. aureus strains to the bactericidal action of these agents in growth and time-kill studies. The possibility that antiseptics and disinfectants contribute to the selection and maintenance of multiply resistant MRSA is considered.
authors.affiliation: Section of Infectious Disease, New Mexico Regional Federal Medical Center, Albuquerque 87108, USA.
authors.forename: L
authors.initials: L
authors.lastname: Irizarry
authors.forename: T
authors.initials: T
authors.lastname: Merlin
authors.forename: J
authors.initials: J
authors.lastname: Rupp
authors.forename: J
authors.initials: J
authors.lastname: Griffith
mesh_terms: D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D002594:Cetylpyridinium / Q000494:pharmacology*; D002710:Chlorhexidine / Q000494:pharmacology*; D008712:Methicillin / Q000494:pharmacology*; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D000891:Anti-Infective Agents, Local; D002594:Cetylpyridinium; D008712:Methicillin; D002710:Chlorhexidine