Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare (THL), PO Box 30, 00271 Helsinki, Finland.
Eur J Clin Microbiol Infect Dis. 2011 Jun;30(6):789-97. doi: 10.1007/s10096-011-1158-5. Epub 2011 Jan 27.
Laboratory-based surveillance of methicillin-resistant Staphylococcus aureus (MRSA) monitors the baseline occurrence of different genotypes and identifies strains and transmission chains responsible for outbreaks. The consequences of substituting pulsed-field gel electrophoresis (PFGE) with spa typing as a first-line typing method were analyzed by typing 589 strains isolated between 1997 and 2006, with a focus on both short- and long-term correspondence between the PFGE and spa typing results. The study, covering these ten years, included all Finnish MRSA blood isolates and representatives of the two most prevalent MRSA strains (PFGE types FIN-4 and FIN-16) in Finland. In addition, all sporadic isolates from 2006 were included. spa typing was more expensive but approximately four times faster to perform than PFGE. Nearly 90% of FIN-4 and FIN-16 isolates showed consistent spa types, t172 and t067, respectively. spa typing predicted the PFGE result of the blood isolates by a Wallace coefficient of 0.9009, recognized internationally successful strains (t041, t067) to be common also in Finland, and identified a separate cluster of isolates, also related in time and place among the FIN-4 strains. Additional typing by another method was needed to provide adequate discrimination or to characterize isolates with a newly recognized spa type in Finland.
基于实验室的耐甲氧西林金黄色葡萄球菌 (MRSA) 监测，监测不同基因型的基线发生情况，并确定导致暴发的菌株和传播链。通过对 1997 年至 2006 年间分离的 589 株菌进行分型，分析了用 spa 分型替代脉冲场凝胶电泳 (PFGE) 作为一线分型方法的后果，重点关注 PFGE 和 spa 分型结果的短期和长期对应关系。这项研究涵盖了这十年，包括所有芬兰耐甲氧西林金黄色葡萄球菌血液分离株以及芬兰两种最流行的耐甲氧西林金黄色葡萄球菌菌株 (PFGE 类型 FIN-4 和 FIN-16) 的代表。此外，还包括 2006 年所有散发性分离株。spa 分型虽然更昂贵，但比 PFGE 快约四倍。近 90%的 FIN-4 和 FIN-16 分离株分别显示出一致的 spa 型 t172 和 t067。spa 分型通过华莱士系数 0.9009 预测了血液分离株的 PFGE 结果，识别出在国际上成功的菌株 (t041、t067) 在芬兰也很常见，并确定了一个单独的分离株群，在 FIN-4 株之间也在时间和地点上存在关联。需要使用另一种方法进行额外的分型，以提供充分的区分度或对芬兰新识别的 spa 型分离株进行特征描述。
