Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica (ITQB), Oeiras, Portugal.
PLoS One. 2013 Apr 3;8(4):e59960. doi: 10.1371/journal.pone.0059960. Print 2013.
According to the EARS-Net surveillance data, Portugal has the highest prevalence of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) in Europe, but the information on MRSA in the community is very scarce and the links between the hospital and community are not known. In this study we aimed to understand the events associated to the recent sharp increase in MRSA frequency in Portugal and to evaluate how this has shaped MRSA epidemiology in the community. With this purpose, 180 nosocomial MRSA isolates recovered from infection in two time periods and 14 MRSA isolates recovered from 89 samples of skin and soft tissue infections (SSTI) were analyzed by pulsed-field gel electrophoresis (PFGE), staphylococcal chromosome cassette mec (SCCmec) typing, spa typing and multilocus sequence typing (MLST). All isolates were also screened for the presence of Panton Valentine leukocidin (PVL) and arginine catabolic mobile element (ACME) by PCR. The results showed that ST22-IVh, accounting for 72% of the nosocomial isolates, was the major clone circulating in the hospital in 2010, having replaced two previous dominant clones in 1993, the Iberian (ST247-I) and Portuguese (ST239-III variant) clones. Moreover in 2010, three clones belonging to CC5 (ST105-II, ST125-IVc and ST5-IVc) accounted for 20% of the isolates and may represent the beginning of new waves of MRSA in this hospital. Interestingly, more than half of the MRSA isolates (8/14) causing SSTI in people attending healthcare centers in Portugal belonged to the most predominant clones found in the hospital, namely ST22-IVh (n = 4), ST5-IVc (n = 2) and ST105-II (n = 1). Other clones found included ST5-V (n = 6) and ST8-VI (n = 1). None of the MRSA isolates carried PVL and only five isolates (ST5-V-t179) carried ACME type II. The emergence and spread of EMRSA-15 may be associated to the observed increase in MRSA frequency in the hospital and the consequent spillover of MRSA into the community.
根据 EARS-Net 监测数据，葡萄牙是欧洲耐甲氧西林金黄色葡萄球菌（MRSA）医院感染率最高的国家，但有关社区 MRSA 的信息非常匮乏，医院与社区之间的联系尚不清楚。在这项研究中，我们旨在了解葡萄牙近期 MRSA 发生率急剧上升的相关事件，并评估这对社区 MRSA 流行病学的影响。为此，我们分析了在两个时间段内从感染中分离的 180 株医院获得性 MRSA 分离株和从 89 份皮肤和软组织感染（SSTI）样本中分离的 14 株 MRSA 分离株，采用脉冲场凝胶电泳（PFGE）、葡萄球菌染色体盒 mec（SCCmec）分型、spa 分型和多位点序列分型（MLST）。所有分离株还通过 PCR 筛查了产肠毒素杀白细胞素（PVL）和精氨酸分解移动元件（ACME）的存在。结果显示，2010 年，ST22-IVh 占医院分离株的 72%，是医院内主要流行克隆，取代了 1993 年之前两种主要流行克隆，即伊比利亚（ST247-I）和葡萄牙（ST239-III 变体）克隆。此外，2010 年，属于 CC5 的三个克隆（ST105-II、ST125-IVc 和 ST5-IVc）占分离株的 20%，可能代表该医院新一波 MRSA 的开始。有趣的是，在葡萄牙就诊的 SSTI 患者中，超过一半的 MRSA 分离株（8/14）属于医院内最主要的克隆，即 ST22-IVh（n=4）、ST5-IVc（n=2）和 ST105-II（n=1）。其他发现的克隆包括 ST5-V（n=6）和 ST8-VI（n=1）。MRSA 分离株均未携带 PVL，只有 5 株（ST5-V-t179）携带 ACME Ⅱ型。EMRSA-15 的出现和传播可能与医院内 MRSA 发生率的上升有关，MRSA 由此溢出到社区。
