Kerschner H, Harrison E M, Hartl R, Holmes M A, Apfalter P
National Reference Center for Antimicrobial Resistance and Nosocomial Infections, Institute for Hygiene, Microbiology and Tropical Medicine, Elisabethinen Hospital, Linz, Austria.
Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom.
New Microbes New Infect. 2014 Nov 12;3:4-9. doi: 10.1016/j.nmni.2014.11.001. eCollection 2015 Jan.
Reports of mecC methicillin-resistant Staphylococcus aureus (MRSA) strains have been published from several European countries. We describe the first six mecC MRSA isolates of human origin from Austria and report the application of a rapid PCR test. Candidate isolates (n = 295) received between 2009 and 2013 were investigated phenotypically by cefoxitin screening and streaking on ChromID MRSA plates. The presence of mecC was confirmed in six isolates from blood cultures, wound swabs and screening samples of four female and two male patients (age range 7-89 years) by an in-house PCR method and the new Genspeed MRSA test (Greiner Bio-One, Kremsmünster, Austria). The mecC MRSA were further characterized by whole genome sequencing, multilocus sequence and spa typing. Antimicrobial susceptibility testing was performed by Eucast disk-diffusion method and Vitek 2. The six mecC MRSA isolates were from two clonal lineages (CC130, including a new single-locus variant, and CC599) and four different spa types (t843, t1535, t3256, t5930). Analysis for virulence factor genes yielded lukED, eta, etd2 and edin-B (CC130 isolates) and tst, lukED, eta and sel (ST599 isolates). The Genspeed MRSA test identified mecC in all isolates whereas Vitek 2 failed to detect methicillin resistance in one isolate. The strains were susceptible to a wide range of non-β-lactam antibiotics. All patients were successfully treated or decolonized. mecC MRSA are present in Austria as colonizers but may also cause infections. Thus, laboratories must choose appropriate test methods such as cefoxitin screening and confirmation using molecular assays specifically targeting mecC.
来自欧洲多个国家的关于耐甲氧西林金黄色葡萄球菌（MRSA）mecC菌株的报告已发表。我们描述了来自奥地利的首例6株源自人类的mecC MRSA分离株，并报告了一种快速PCR检测方法的应用。对2009年至2013年间收集的295株候选分离株进行了头孢西丁筛选及在ChromID MRSA平板上划线的表型研究。通过内部PCR方法及新型Genspeed MRSA检测（奥地利克雷姆斯明斯特的Greiner Bio-One公司），在来自4名女性和2名男性患者（年龄范围7至89岁）的血培养、伤口拭子及筛查样本的6株分离株中确认了mecC的存在。通过全基因组测序、多位点序列分型及spa分型对mecC MRSA进行了进一步特征分析。采用Eucast纸片扩散法和Vitek 2进行了药敏试验。这6株mecC MRSA分离株来自两个克隆谱系（CC130，包括一个新的单基因座变体，以及CC599）和4种不同的spa型（t843、t1535、t3256、t5930）。对毒力因子基因的分析发现lukED、eta、etd2和edin-B（CC130分离株）以及tst、lukED、eta和sel（ST599分离株）。Genspeed MRSA检测在所有分离株中均鉴定出mecC，而Vitek 2在1株分离株中未能检测出甲氧西林耐药性。这些菌株对多种非β-内酰胺类抗生素敏感。所有患者均成功接受治疗或实现去定植。mecC MRSA在奥地利作为定植菌存在，但也可能引起感染。因此，实验室必须选择合适的检测方法，如头孢西丁筛选及使用专门针对mecC的分子检测方法进行确认。
