Laboratoire de Référence MRSA-Staphylocoques, Service de Microbiologie, Université Libre de Bruxelles (ULB)-Hôpital Erasme, Brussels, Belgium.
Eur J Clin Microbiol Infect Dis. 2013 May;32(5):613-20. doi: 10.1007/s10096-012-1784-6. Epub 2012 Dec 13.
The present study reports the evolution of the demographic characteristics and the molecular epidemiology of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) in Belgium from 2005 to 2009. Four hundred and ten CA-MRSA isolates were prospectively collected and screened for the presence of Panton-Valentin leucocidin (PVL) and toxic shock syndrome toxin 1 (TSST-1) encoding genes, while clinical information were recorded. PVL- and TSST-1-positive isolates were genotyped by pulsed-field gel electrophoresis (PFGE). Staphylococcal cassette chromosome mec (SCCmec) type, spa type and multilocus sequence type (MLST) were determined on representative isolates. One hundred and fifty-nine (39 %) isolates were PVL-positive. PVL-positive isolates were significantly more frequently isolated from skin or soft tissue than PVL-negative isolates, causing mainly subcutaneous abscesses and furuncles. Patients with PVL-positive CA-MRSA were significantly younger than patients with PVL-negative CA-MRSA. Eighty-seven percent of the PVL-positive isolates belonged to a limited number (n = 7) of PFGE types belonging to sequence types (ST) ST80, ST8, ST30, ST5, ST152, ST338 and a new ST, a single-locus variant of ST1. A temporal evolution of the distribution of these PFGE types was observed, characterised by (1) the dissemination of the ST8-SCCmecIV arcA-positive (USA300) genotype and (2) a genetic diversification. Forty-seven (11 %) strains were TSST-1-positive, of which 65 % clustered into four PFGE types, all belonging to ST5. The epidemiology of CA-MRSA in Belgium is changing, as the rapid diffusion of the USA300 clone seems to occur, together with a clonal diversification.
本研究报告了 2005 年至 2009 年期间比利时社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）的人口统计学特征和分子流行病学的演变。前瞻性收集了 410 株 CA-MRSA 分离株，并筛选了携带杀白细胞素（PVL）和中毒性休克综合征毒素 1（TSST-1）编码基因的情况，并记录了临床信息。对 PVL 和 TSST-1 阳性分离株进行脉冲场凝胶电泳（PFGE）基因分型。对代表性分离株进行葡萄球菌盒染色体 mec（SCCmec）型、spa 型和多位点序列型（MLST）的测定。159 株（39%）分离株为 PVL 阳性。PVL 阳性分离株明显更多地从皮肤或软组织中分离出来，而不是 PVL 阴性分离株，主要引起皮下脓肿和疖。PVL 阳性 CA-MRSA 患者明显比 PVL 阴性 CA-MRSA 患者年轻。87%的 PVL 阳性分离株属于少数（n=7）PFGE 型，属于 ST80、ST8、ST30、ST5、ST152、ST338 和一种新的 ST，即 ST1 的单一位点变异型。观察到这些 PFGE 型分布的时间演变，其特征在于（1）ST8-SCCmecIVarcA 阳性（USA300）基因型的传播和（2）遗传多样化。47 株（11%）为 TSST-1 阳性，其中 65%聚集成 4 种 PFGE 型，均属于 ST5。比利时 CA-MRSA 的流行病学正在发生变化，因为 USA300 克隆的快速扩散似乎与克隆多样化同时发生。
