Center for Hospital Infection Control, Chinese PLA Institute for Disease Control & Prevention, Academy of Military Medical Sciences, Beijing, China.
Department of Clinical Microbiology, Urumqi General Hospital of Lanzhou Military Command, PLA, Urumqi, China.
PLoS One. 2014 Apr 24;9(4):e96255. doi: 10.1371/journal.pone.0096255. eCollection 2014.
Staphylococcus aureus belongs to one of the most common bacteria causing healthcare and community associated infections in China, but their molecular characterization has not been well studied. From May 2011 to June 2012, a total of 322 non-duplicate S. aureus isolates were consecutively collected from seven tertiary care hospitals in seven cities with distinct geographical locations in China, including 171 methicillin sensitive S. aureus (MSSA) and 151 MRSA isolates. All isolates were characterized by spa typing. The presence of virulence genes was tested by PCR. MRSA were further characterized by SCCmec typing. Seventy four and 16 spa types were identified among 168 MSSA and 150 MRSA, respectively. One spa type t030 accounted for 80.1% of all MRSA isolates, which was higher than previously reported, while spa-t037 accounted for only 4.0% of all MRSA isolates. The first six spa types (t309, t189, t034, t377, t078 and t091) accounted for about one third of all MSSA isolates. 121 of 151 MRSA isolates (80.1%) were identified as SCCmec type III. pvl gene was found in 32 MSSA (18.7%) and 5 MRSA (3.3%) isolates, with ST22-MSSA-t309 as the most commonly identified strain. Compared with non-epidemic MRSA clones, epidemic MRSA clones (corresponding to ST239) exhibited a lower susceptibility to rifampin, ciprofloxacin, gentamicin and trimethoprim-sulfamethoxazole, a higher prevalence of sea gene and a lower prevalence of seb, sec, seg, sei and tst genes. The increasing prevalence of multidrug resistant spa-t030 MRSA represents a major public health problem in China.
金黄色葡萄球菌属于中国最常见的引起医院和社区感染的细菌之一，但它们的分子特征尚未得到很好的研究。2011 年 5 月至 2012 年 6 月，连续从中国七个地理位置不同的城市的七家三级医院采集了 322 株非重复的金黄色葡萄球菌分离株，包括 171 株甲氧西林敏感金黄色葡萄球菌（MSSA）和 151 株 MRSA 分离株。所有分离株均通过 spa 分型进行特征描述。通过 PCR 检测毒力基因的存在。MRSA 进一步通过 SCCmec 分型进行特征描述。在 168 株 MSSA 和 150 株 MRSA 中分别鉴定出 74 种和 16 种 spa 型。一株 spa 型 t030 占所有 MRSA 分离株的 80.1%，高于之前的报道，而 spa-t037 仅占所有 MRSA 分离株的 4.0%。前六种 spa 型（t309、t189、t034、t377、t078 和 t091）约占所有 MSSA 分离株的三分之一。151 株 MRSA 分离株中的 121 株（80.1%）被鉴定为 SCCmec 型 III。在 32 株 MSSA（18.7%）和 5 株 MRSA（3.3%）分离株中发现了 pvl 基因，最常见的菌株为 ST22-MSSA-t309。与非流行型 MRSA 克隆相比，流行型 MRSA 克隆（对应于 ST239）对利福平、环丙沙星、庆大霉素和复方新诺明的敏感性较低，sea 基因的流行率较高，seb、sec、seg、sei 和 tst 基因的流行率较低。多药耐药性 spa-t030 MRSA 的流行率不断上升，是中国面临的一个主要公共卫生问题。
