Fast-acting bactericidal activity of olanexidine gluconate against qacA/B-positive methicillin-resistant Staphylococcus aureus.

The qacA/B gene is one of the major determinants of resistance to antiseptics in methicillin-resistant Staphylococcus aureus (MRSA). Here, we compared the fast-acting bactericidal activity of skin antiseptics, including olanexidine gluconate (OLG), a new biguanide antiseptic agent introduced in Japan, against clinical qacA/B-positive MRSA strains by determination of minimum bactericidal concentration and time-kill assay. Our findings provide, for the first time, data indicating that the fast-acting bactericidal activity of OLG against qacA/B-positive MRSA is higher than that of chlorhexidine gluconate, even though both are biguanide antiseptics.