Schmitz F J, Steiert M, Tichy H V, Hofmann B, Verhoef J, Heinz H P, Köhrer K, Jones M E
Institute for Medical Microbiology and Virology, Heinrich-Heine-Universität Düsseldorf, Germany.
J Med Microbiol. 1998 Apr;47(4):341-51. doi: 10.1099/00222615-47-4-341.
Nosocomial infections caused by methicillin-resistant Staphylococcus aureus (MRSA) represent an increasing problem in hospitals. Quick and reliable typing methods are required to obtain information about the relatedness of MRSA isolates and to allow faster implementation of appropriate infection control measures. This investigation describes the distribution of MRSA isolates from 11 hospitals in the Düsseldorf region of Germany, and the ability of six different genotypic typing techniques -- pulsed-field gel electrophoresis (PFGE), random amplification of polymorphic DNA (RAPD), 16S-23S rDNA spacer amplification, protein A-gene PCR, PCR characterisation of the hypervariable region (HVR) adjacent to mecA, and coagulase gene-PCR -- to detect different unrelated types. Of 7814 S. aureus isolates tested, 489 (6.3%) were MRSA, of which 183 were selected for subsequent molecular analyses on the basis of being the first MRSA isolated from colonised or infected patients. Larger hospitals had a higher incidence of MRSA and a greater variability in genotypes than smaller hospitals. All methods confirmed the presence of two main clonal types. The ability of techniques to detect different unrelated types was found to be as follows: PFGE, 28 types; 16S-23S rDNA spacer-amplification, 10 types; RAPD, nine types; protein A-gene PCR, five types; HVR-PCR, five types; and coa gene-PCR, two types. Combination of PFGE and one other PCR-based method (spacer-amplification, RAPD or protein-A gene PCR) provided the best resolution of types and allowed the identification of subtypes. Similar molecular types were identified with international MRSA isolates. Although PCR-based techniques have the advantage of rapid performance and easy handling, their discriminatory capacity is inferior compared to the more labour intensive PFGE.
耐甲氧西林金黄色葡萄球菌（MRSA）引起的医院感染在医院中是一个日益严重的问题。需要快速可靠的分型方法来获取有关MRSA分离株相关性的信息，并更快地实施适当的感染控制措施。本研究描述了德国杜塞尔多夫地区11家医院MRSA分离株的分布情况，以及六种不同的基因分型技术——脉冲场凝胶电泳（PFGE）、随机扩增多态性DNA（RAPD）、16S - 23S rDNA间隔区扩增、蛋白A基因PCR、mecA相邻高变区（HVR）的PCR特征分析以及凝固酶基因PCR——检测不同无关类型的能力。在检测的7814株金黄色葡萄球菌分离株中，489株（6.3%）为MRSA，其中183株因是首次从定植或感染患者中分离出的MRSA而被选用于后续分子分析。大型医院的MRSA发病率高于小型医院，且基因型变异性更大。所有方法均证实存在两种主要克隆类型。发现各技术检测不同无关类型的能力如下：PFGE，28种类型；16S - 23S rDNA间隔区扩增，10种类型；RAPD，9种类型；蛋白A基因PCR，5种类型；HVR - PCR，5种类型；coa基因PCR，2种类型。PFGE与另一种基于PCR的方法（间隔区扩增、RAPD或蛋白A基因PCR）相结合可提供最佳的分型分辨率，并能鉴定亚型。与国际MRSA分离株鉴定出了相似的分子类型。尽管基于PCR的技术具有操作快速、易于处理的优点，但其鉴别能力与更为耗时的PFGE相比仍较差。
