Department of Functional Biology (Microbiology Section), Faculty of Medicine, University of Oviedo, Julián Clavería 6, 33006 Oviedo, Spain.
Microb Pathog. 2013 Jan;54:26-33. doi: 10.1016/j.micpath.2012.09.001. Epub 2012 Sep 13.
The population structure of 111 methicillin-susceptible Staphylococcus aureus (MSSA), recovered in Spain from healthy and risk-free carriers was investigated using pulsed-field gel electrophoresis (PFGE), spa (staphylococcal protein A) typing, multi locus sequence typing (MLST) and the accessory gene regulator (agr). Results from the different techniques were highly concordant, and revealed twelve clonal complexes (CCs): CC30 (27%), CC5 (18.9%), CC45 (16.2%), CC15 (11.7%), CC25 (8.1%), CC1, CC9 (3.6% each), CC59, CC97 and CC121 (2.7% each), CC72 (1.8%) and CC8 (0.9%). Isolates with genetic backgrounds of hospital-acquired MSSA were detected and, consistent with the ability of diverse MSSA to act as recipients of the SCCmec cassette, a MSSA isolate from a healthy carrier shared the ST, spa-type and agr-type of a MRSA clone recovered in a hospital of the same region. All except two fragments of the PGFE-profiles of these isolates were identical, and the differential fragment of the MRSA carried mecA. Analyses of the exotoxin gene content of the nasal isolates revealed an increase in the number of exotoxin genes over time. This, together with the detection of lukPV and the high frequency of tst, exfoliatin and enterotoxin genes, is worrisome and requires further surveillance.
111 株耐甲氧西林金黄色葡萄球菌（MSSA）来自西班牙健康无风险携带者，采用脉冲场凝胶电泳（PFGE）、spa（葡萄球菌蛋白 A）分型、多位点序列分型（MLST）和辅助基因调控（agr）对其进行了种群结构分析。不同技术的结果高度一致，共发现 12 个克隆复合体（CC）：CC30（27%）、CC5（18.9%）、CC45（16.2%）、CC15（11.7%）、CC25（8.1%）、CC1、CC9（各 3.6%）、CC59、CC97 和 CC121（各 2.7%）、CC72（1.8%）和 CC8（0.9%）。检测到了医院获得性 MSSA 的遗传背景的分离株，与多种 MSSA 作为 SCCmec 盒的受体的能力一致，从同一地区医院回收的一株 MRSA 克隆的 ST、spa 型和 agr 型与健康携带者的 MSSA 分离株相同。除了这些分离株的 PGFE 图谱的两个片段外，所有片段都相同，MRSA 携带的差异片段为 mecA。对鼻分离株中外毒素基因含量的分析表明，外毒素基因的数量随时间增加。这与 lukPV 的检测以及 tst、剥脱毒素和肠毒素基因的高频率一起令人担忧，需要进一步监测。
