Antiseptic susceptibility and distribution of antiseptic-resistance genes in methicillin-resistant Staphylococcus aureus

We examined the antiseptic susceptibilities and distribution of antiseptic- resistance genes qacA and smi in 98 isolates of methicillin-resistant Staph ylococcus aureus obtained in 1992. Seventy-one strains were resistant to an tiseptics. The qacA and smr genes were detected in 10 and 20 strains, respe ctively The remaining 41 strains without qacA and smr were divided into two groups that exhibited low-level (n = 22) and high-level (n = 19) resistanc e to acriflavin. DNA cloning and sequencing suggested that norfloxacin-resi stance gene norA was responsible for the high-level resistance to acriflavi n. Our results indicated that four or more antiseptic-resistance genes exis t in methicillin-resistant S. aureus and that antiseptic-resistant methicil lin-resistant S, aureus strains without qacA and sr,li are widely spread in Japan. (C) 1999 Federation of European Microbiological Societies. Publishe d by Elsevier Science B.V. All rights reserved.