Ho Pak-Leung, Cheung Clara, Mak Gannon C, Tse Cindy W S, Ng Tak-Keung, Cheung Chris H Y, Que Tak-Lun, Lam Rebecca, Lai Raymond W M, Yung Raymond W H, Yuen Kwok-Yung
Department of Microbiology and Centre of Infection, University of Hong Kong, Hong Kong SAR, PR China.
Diagn Microbiol Infect Dis. 2007 Feb;57(2):145-51. doi: 10.1016/j.diagmicrobio.2006.08.003. Epub 2006 Sep 20.
This study evaluated the clinical and epidemiologic features of individuals with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in Hong Kong from January 2004 through December 2005. Twenty-four episodes of skin and soft tissue infections and 1 episode of meningitis due to CA-MRSA were identified. CA-MRSA infections or carriage was found in 6 (13%) of 46 household contacts. A total of 29 isolates were analyzed by the Staphylococcus cassette chromosome mec (SCCmec) typing, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing. In addition, polymerase chain reaction detection of the genes encoding Panton-Valentine leukocidin was also carried out. It was observed that 24 had SCCmec IV/IVA and 5 had SCCmec V, and 23 were pvl positive. PFGE analysis clustered all except 1 isolate into 3 pulsed-field types (PFTs), HKU100 through HKU300. The HKU100 isolates had genotype ST30-IV identical to the Southwest Pacific clone. The HKU200 isolates belonged to ST59-V and were multiresistant, including an ermB-mediated macrolide resistance trait, which is characteristic of the predominant CA-MRSA clone in Taiwan. The HKU300 isolates had unique features (ST8, Panton-Valentine leukocidin negative, and SCCmec IVA) typical of CA-MRSA in Japan. In conclusion, CA-MRSA has a propensity to spread within families. Our findings showed that CA-MRSA strains in Hong Kong have diverse genetic backgrounds.
本研究评估了2004年1月至2005年12月香港社区获得性耐甲氧西林金黄色葡萄球菌（CA-MRSA）感染者的临床和流行病学特征。共识别出24例由CA-MRSA引起的皮肤和软组织感染病例以及1例脑膜炎病例。在46名家庭接触者中，有6人（13%）被发现感染或携带CA-MRSA。对总共29株分离株进行了葡萄球菌盒式染色体mec（SCCmec）分型、脉冲场凝胶电泳（PFGE）和多位点序列分型分析。此外，还进行了编码杀白细胞素的基因的聚合酶链反应检测。结果发现，24株具有SCCmec IV/IVA型，5株具有SCCmec V型，23株pvl呈阳性。PFGE分析将除1株分离株外的所有分离株聚为3种脉冲场型（PFTs），即HKU100至HKU300。HKU100分离株的基因型为ST30-IV，与西南太平洋克隆相同。HKU200分离株属于ST59-V型，具有多重耐药性，包括ermB介导的大环内酯类耐药特性，这是台湾主要的CA-MRSA克隆的特征。HKU300分离株具有日本CA-MRSA典型的独特特征（ST8、杀白细胞素阴性和SCCmec IVA）。总之，CA-MRSA有在家庭中传播的倾向。我们的研究结果表明，香港的CA-MRSA菌株具有多样的遗传背景。
