Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Urology Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Microb Pathog. 2017 Oct;111:71-74. doi: 10.1016/j.micpath.2017.08.026. Epub 2017 Aug 18.
Efflux pumps are well known as a key role to fluoroquinolone resistance in methicillin-resistant Staphylococcus aureus (MRSA). In this study, among 60 clinical MRSA isolates, 42 isolates (70%) were resistant to ciprofloxacin. MRSA were isolated to detect efflux genes including norA, norB, norC, mepA, sepA, mdeA, qacA/B and smr. Isolates subjected to PCR detection and DNA sequence analysis for these genes. PCR detection showed that 42 isolates (70%) contained at least one efflux pump gene. Among ciprofloxacin-resistant isolates, mdeA and qacA/B genes were found with the highest (61.7%) and lowest (3.3%) frequency, respectively. We also observed that the highest minimum inhibitory concentrations of ciprofloxacin in the presence of mdeA+mepA+norA-C+sepA+smr combination. This type of combination may have the greatest impact on resistance to ciprofloxacin. Finally, compared to previous studies, our study demonstrates that prevalence of ciprofloxacin resistance has been increasing among MRSA clinical isolates.
外排泵是耐甲氧西林金黄色葡萄球菌 (MRSA) 对氟喹诺酮类药物耐药的关键因素。在这项研究中，在 60 株临床分离的 MRSA 中，有 42 株（70%）对环丙沙星耐药。MRSA 的分离用于检测包括 norA、norB、norC、mepA、sepA、mdeA、qacA/B 和 smr 在内的外排泵基因。对这些基因进行 PCR 检测和 DNA 序列分析。PCR 检测显示，42 株（70%）至少含有一个外排泵基因。在环丙沙星耐药的分离株中，mdeA 和 qacA/B 基因的检出率最高（61.7%）和最低（3.3%）。我们还观察到，mdeA+mepA+norA-C+sepA+smr 联合存在时，环丙沙星的最低抑菌浓度最高。这种组合可能对环丙沙星的耐药性影响最大。最后，与之前的研究相比，我们的研究表明，MRSA 临床分离株中环丙沙星耐药的流行率一直在增加。
