Department of Clinical Laboratory, Shanghai First People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
PLoS One. 2012;7(5):e37005. doi: 10.1371/journal.pone.0037005. Epub 2012 May 18.
The emergence and prevalence of high-level mupirocin-resistant, methicillin-resistant Staphylococcus aureus (MuH MRSA) is challenging the eradication of MRSA nasal carriage and the treatment of skin and soft tissue infections. To understand the potentially pathogenetic capacity and the genetic basis of MuH MRSA, it is important to have a detailed knowledge of the molecular traits of this organism. Fifty three MuH MRSA isolates were gathered from Shanghai (28 isolates) and Wenzhou (25 isolates) in China. These isolates, consisting of 27 different PFGE-SCCmec-spa patterns, were examined by PCR for 35 virulence genes and further typed using agr (accessory gene regulator) typing and MLST (multilocus sequence typing). All 53 strains were positive for the genes hlg/hlg variant and icaD, and negative for seb, sed, see, seh, eta, etb, hld, cap-5, and ACME-arcA. Compared with Wenzhou isolates, Shanghai isolates were more likely to carry seg (P = 0.002) and several other genes which were not found in Wenzhou strains such as sec, sei, tst (P<0.001 each), and pvl (P = 0.012), and less likely to contain sea (P<0.001), cna (P = 0.031), and efb (P = 0.045). MLST and agr typing showed that ST239-agr1, ST5-agr1, and ST239-agr2 were the common lineages in MuH MRSA isolates from these two different regions. Our results indicated that MuH MRSA strains from two different geographic regions of China have differences in distribution of some virulence genes, while their major MLST-agr genetic backgrounds were accordant.
中国上海（28 株）和温州（25 株）采集的 53 株高水平莫匹罗星耐药、耐甲氧西林金黄色葡萄球菌（MuH MRSA），通过 PCR 检测 35 种毒力基因，并进行 agr（辅助基因调节）分型和 MLST（多位点序列分型）进一步分型。所有 53 株均携带 hlg/hlg 变体和 icaD 基因，不携带 seb、sed、see、seh、eta、etb、hld、cap-5 和 ACME-arcA 基因。与温州分离株相比，上海分离株携带 seg（P=0.002）和其他一些在温州分离株中未发现的基因，如 sec、sei、tst（P<0.001）和 pvl（P=0.012），而携带 sea（P<0.001）、cna（P=0.031）和 efb（P=0.045）的可能性较低。MLST 和 agr 分型显示，ST239-agr1、ST5-agr1 和 ST239-agr2 是这两个不同地区 MuH MRSA 分离株的常见谱系。结果表明，来自中国两个不同地理区域的 MuH MRSA 菌株在一些毒力基因的分布上存在差异，而其主要 MLST-agr 遗传背景是一致的。
