Liu Qingzhong, Zhao Huanqiang, Han Lizhong, Shu Wen, Wu Qiong, Ni Yuxing
Department of Clinical Laboratory, Shanghai First People's Hospital, Shanghai Jiaotong University, Shanghai, China.
Department of Clinical Microbiology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
Diagn Microbiol Infect Dis. 2015 Aug;82(4):278-83. doi: 10.1016/j.diagmicrobio.2015.03.023. Epub 2015 Apr 9.
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.
本研究的目的是确定高水平耐莫匹罗星、耐甲氧西林金黄色葡萄球菌（MuH MRSA）中抗微生物剂决定簇的流行情况以及对氯己定的敏感性。通过聚合酶链反应（PCR）分析了53株MuH MRSA分离株的质粒携带基因（qacA/B、smr、qacG、qacH和qacJ）；通过PCR和定量逆转录PCR（qRT-PCR）分析了染色体介导基因（norA、norB、norC、mepA、mdeA、sepA和sdrM）；并通过MIC和最低杀菌浓度（MBC）分析了对氯己定的敏感性。此外，在MBC检测中，在3.0%牛血清白蛋白（BSA）存在的情况下测试了消毒剂的效果。在所研究的分离株中，主要发现了质粒携带基因qacA/B（83.0%）和smr（77.4%）以及染色体介导基因norA（49.0%）和norB（28.8%）的过表达，并且90.6%的分离株对氯己定具有耐受性。在BSA存在的情况下，这些分离株对氯己定的平均MBC升至256μg/mL。总之，我们的结果表明，对MuH MRSA分离株进行抗微生物剂敏感性监测对于医院感染控制至关重要。
