Evaluation of antiseptics by the modified phenol coefficient method: sensitivity of methicillin-resistant Staphylococcus aureus.
The relationship between an effective concentration and the duration of exposure to antiseptics was evaluated in strains of Staphylococcus aureus with a known genetic background, which include methicillin-resistant strains, using a modified version of the phenol coefficient method as part of an effort to investigate the antiseptic resistance of S. aureus. Chlorhexidine digluconate killed an antiseptic-sensitive strain within 1.5 min at 22 degrees C at a standard concentration (0.1%), whereas resistant strains still survived after 1.5 min. Povidone-iodine killed the sensitive strain within 1.5 min at a concentration of 0.1%, whereas it took this agent 3.0 and 4.5 min to kill low- and high-level resistant strains, respectively, at a concentration of 0.8%. These results indicate that the modified phenol coefficient method used is suitable for the evaluation of the sensitivity of microorganisms to antiseptics. An antiseptic-resistant chain that was associated with the ebr gene exhibited cross-resistance to povidone-iodine.
Sasatsu
M
M
Department of Microbiology, Tokyo College of Pharmacy, Japan.
Shimizu
K
K
Noguchi
N
N
Kono
M
M
D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D002710:Chlorhexidine / Q000031:analogs & derivatives / Q000494:pharmacology; D016106:Methicillin Resistance; D019800:Phenol; D010636:Phenols / Q000494:pharmacology; D011206:Povidone-Iodine / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects*
D000891:Anti-Infective Agents, Local; D010636:Phenols; D019800:Phenol; D011206:Povidone-Iodine; C010882:chlorhexidine gluconate; D002710:Chlorhexidine