Molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from patients with bacteremia based on MLST, SCCmec, spa, and agr locus types analysis
Molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from patients with bacteremia based on MLST, SCCmec, spa, and agr locus types analysis
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DOI：
10.1016/j.micpath.2017.01.055
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发表时间：
2017-03-01
影响因子：
3.8
通讯作者：
Dabiri, Hossein
中科院分区：
文献类型：
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作者：
Goudarzi, Mehdi;Seyedjavadi, Sima Sadat;Dabiri, Hossein
耐甲氧西林金黄色葡萄球菌的广泛出现，作为医院感染的常见原因，正成为全球公共卫生领域的一个严重问题。本研究的目的是调查从菌血症患者中分离的耐甲氧西林金黄色葡萄球菌的药物敏感性模式，毒力基因频率和分子特征。2015年2月至2016年1月期间，共收集了128株耐甲氧西林金黄色葡萄球菌分离株。采用纸片扩散法对分离菌株进行体外药敏试验。用常规PCR方法检测粘附基因（can、bbp、ebp、fnbB、fnbA、clfB、clfA）和毒素基因（etb、eta、pvl、tst），并进行agr分型、SCCmec、MLST和spa分型。所有耐甲氧西林金黄色葡萄球菌分离株均对利奈唑胺、替考拉宁和万古霉素敏感。对所测试的抗生素的耐药性从青霉素的97.7%到莫匹罗星的24.2%不等。本研究中的多药耐药率为97.7%。最常见的毒素和粘附基因分别为tst（58.6%）和clfB（100%）。大部分SCCmec III分离株分布在agr组I中，而SCCmec IV和II分离株分布在agr组III中。MRSA分离株的多位点序列分型（MLST）显示5种不同的序列类型：ST 239（43%）、ST 22（39.8%）、ST 585（10.9%）、ST 45（3.9%）和ST 240（23%）。pv 1阳性菌株均属于ST 22-SCCmec IV/t790克隆，均为MDR。在7种SPA类型中，最常见的是t790（273%）、t037（21.9%）和t030（14.1%）。其中t016、t924和t383型分别为首次在亚洲和伊朗发现。结果表明，在研究的医院中流通的温泉类型各不相同，这支持需要进行未来的监测研究，以了解耐甲氧西林金黄色葡萄球菌的分布，从而更有效地控制感染。(C)2017爱思唯尔有限公司版权所有
The widespread emergence of methicillin resistant Staphylococcus aureus, as a common cause of nosocomial infections, is becoming a serious concern in global public health. The objective of the present study was to investigate antimicrobial susceptibility pattern, frequency of virulence genes and molecular characteristics of methicillin-resistant Staphylococcus aureus strains isolated from patients with bacteremia. A total of 128 methicillin-resistant Staphylococcus aureus isolates were collected during February 2015 to January 2016. In vitro antimicrobial susceptibility of the isolates was assessed using the disk diffusion method. Conventional PCR was performed for the detection of adhesion (can, bbp, ebp, fnbB, fnbA, clfB, clfA) and toxin (etb, eta, pvl, tst) encoding genes, determining the agr type, SCCmec, MLST and spa typing of the isolates. All the methicillin-resistant Staphylococcus aureus isolates were found to be sensitive to linezolid, teicoplanin, and vancomycin. Resistance to the tested antibiotics varied from 97.7% for penicillin to 24.2% for mupirocin. The rate of multi drug resistance (MDR) in the present study was 97.7%. The most commonly detected toxin and adhesion genes were tst (58.6%), and clfB (100%), respectively. The majority of SCCmec III isolates were found in agr group I while SCCmec IV and II isolates were distributed among agr group III. Multilocus Sequence Typing (MLST) of the MRSA isolates showed five different sequence types: ST239 (43%), ST22 (39.8%), ST585 (10.9%), ST45 (3.9%) and ST240 (23%). All of the pvl positive strains belonged to ST22-SCCmec IV/t790 clone and were MDR. Among different 7 spa types, the most common were t790 (273%), t037 (21.9%), and t030 (14.1%). spa types t016, t924 and spa type t383 were reported for the first time from Asia and Iran, respectively. It was shown that spa types circulating in the studied hospitals varied which support the need to perform future surveillance studies in order to understand methicillin-resistant Staphylococcus aureus distribution and thus more effective infection control. (C) 2017 Elsevier Ltd. All rights reserved.