title: Frequency of biocide-resistant genes and susceptibility to chlorhexidine in high-level mupirocin-resistant, methicillin-resistant Staphylococcus aureus (MuH MRSA).
abstract: The aim of this study was to determine the prevalence of biocide-resistant determinants and the susceptibility to chlorhexidine in high-level mupirocin-resistant, methicillin-resistant Staphylococcus aureus (MuH MRSA). Fifty-three MuH MRSA isolates were analyzed for plasmid-borne genes (qacA/B, smr, qacG, qacH, and qacJ) by polymerase chain reaction (PCR); for chromosome-mediated genes (norA, norB, norC, mepA, mdeA, sepA, and sdrM) by PCR and quantitative reverse transcription-PCR (qRT-PCR); and for susceptibility to chlorhexidine by MIC and minimum bactericidal concentration (MBC). Furthermore, disinfectant efficacy was tested in the presence of 3.0% bovine serum albumin (BSA) in MBC detection. The plasmid-borne genes qacA/B (83.0%) and smr (77.4%) and overexpressions of chromosome-mediated genes norA (49.0%) and norB (28.8%) were predominantly found in isolates studied, and 90.6% of the isolates revealed tolerance to chlorhexidine. In the presence of BSA, the average MBC of chlorhexidine for these isolates rose to 256 μg/mL. Altogether, our results suggest that surveillance of sensitivity to biocides among MuH MRSA isolates is essential for hospital infection control.
authors.affiliation: Department of Clinical Laboratory, Shanghai First People's Hospital, Shanghai Jiaotong University, Shanghai, China. Electronic address: jiaodamedicine@foxmail.com.
authors.forename: Qingzhong
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Clinical Laboratory, Shanghai First People's Hospital, Shanghai Jiaotong University, Shanghai, China. Electronic address: zhaohuanqiang@163.com.
authors.forename: Huanqiang
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Clinical Microbiology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China. Electronic address: lizhong_han@yahoo.com.
authors.forename: Lizhong
authors.initials: L
authors.lastname: Han
authors.affiliation: Department of Clinical Laboratory, Shanghai First People's Hospital, Shanghai Jiaotong University, Shanghai, China. Electronic address: shuwen654321@163.com.
authors.forename: Wen
authors.initials: W
authors.lastname: Shu
authors.affiliation: Department of Clinical Laboratory, Shanghai Sixth People's Hospital, Shanghai Jiaotong University, Shanghai, China. Electronic address: joanwu29@hotmail.com.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Department of Clinical Microbiology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China. Electronic address: yuxingni@yahoo.com.cn.
authors.forename: Yuxing
authors.initials: Y
authors.lastname: Ni
mesh_terms: D002710:Chlorhexidine / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000235:genetics; D004202:Disinfectants / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D005798:Genes, Bacterial; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D016712:Mupirocin / Q000494:pharmacology*; D010957:Plasmids; D016133:Polymerase Chain Reaction
chemical_list: D004269:DNA, Bacterial; D004202:Disinfectants; D016712:Mupirocin; D002710:Chlorhexidine
keywords: Biocide resistance genes; Chlorhexidine; Decreased susceptibility; MuH MRSA