Department of Sciences for Woman and Child's Health, University of Florence, Florence, Italy.
J Cyst Fibros. 2011 Dec;10(6):407-11. doi: 10.1016/j.jcf.2011.06.005. Epub 2011 Jul 12.
The genetic background, transmissibility and virulence of MRSA have been poorly investigated in the cystic fibrosis (CF) population. The aim of this multicentre study was to analyse MRSA strains isolated from CF patients attending nine Italian CF care centres during a two-year period (2004-2005). All CF patients infected by MRSA were included.
Antibiotic susceptibility testing, SCCmec typing, Panton-Valentine Leukocidin (PVL) production, and Multi Locus Sequence Typing (MLST) analysis were carried out on collected isolates (one strain per patient).
One hundred and seventy-eight strains isolated from 2360 patients attending the participating centres were analysed. We detected 56 (31.4%) SCCmec IV PVL-negative strains, with a resistance rate of 80.3% to clindamycin and of 14.5% to trimethoprim/sulphamethoxazole. MLST analysis showed that many isolates belonged to known epidemic lineages. The largest clone grouping of 29 isolates from 6 centres had the genetic background (ST8-MRSA-IV) of the American lineages USA300 and USA500, thus demonstrating the diffusion of these strains in a population considered at risk for hospital associated infections.
Known MRSA epidemic clones such as USA600, USA800, USA1100, and UK EMRSA-3 were described for the first time in Italy. The diffusion of MRSA strains with high pathogenic potential in the CF population suggests that analysis of the MRSA strains involved in pulmonary infections of these patients is needed.
在囊性纤维化（CF）人群中，对耐甲氧西林金黄色葡萄球菌（MRSA）的遗传背景、传染性和毒力的研究甚少。本多中心研究的目的是分析 2004-2005 年期间在意大利九个 CF 护理中心就诊的 CF 患者分离的 MRSA 菌株。所有感染 MRSA 的 CF 患者均包括在内。
对收集的分离株（每位患者一株）进行抗生素敏感性试验、SCCmec 型分型、Panton-Valentine 白细胞毒素（PVL）产生和多位点序列分型（MLST）分析。
对参加中心的 2360 名患者中分离的 178 株进行了分析。我们检测到 56 株（31.4%）SCCmecIVPVL 阴性株，对克林霉素的耐药率为 80.3%，对 trimethoprim/sulphamethoxazole 的耐药率为 14.5%。MLST 分析表明，许多分离株属于已知的流行谱系。来自 6 个中心的 29 个分离株的最大克隆群具有遗传背景（ST8-MRSA-IV）的美国谱系 USA300 和 USA500，这表明这些菌株在被认为存在医院相关感染风险的人群中扩散。
首次在意大利描述了已知的 MRSA 流行克隆，如 USA600、USA800、USA1100 和 UK EMRSA-3。高致病性 MRSA 菌株在 CF 人群中的扩散表明，需要对这些患者肺部感染中涉及的 MRSA 菌株进行分析。
