Struelens M J, Deplano A, Godard C, Maes N, Serruys E
Unité d'Epidémiologie, Hôpital Erasme, Université Libre de Bruxelles, Belgium.
J Clin Microbiol. 1992 Oct;30(10):2599-605. doi: 10.1128/jcm.30.10.2599-2605.1992.
To evaluate the usefulness of phenotypic and genotypic analyses for the epidemiologic typing of methicillin-resistant Staphylococcus aureus (MRSA), we characterized 64 epidemic MRSA isolates and 10 sporadic methicillin-susceptible S. aureus isolates from a university hospital and 18 MRSA isolates from hospitals in different geographical areas. Chromosomal DNA macrorestriction analysis with SstII was resolved by pulsed-field gel electrophoresis and compared with antibiotype analysis, phage type analysis, and standard genomic DNA restriction analysis with BglII. Indices of the discriminatory ability of these methods were 0.982, 0.959, 0.947, and 0.959, respectively. Macrorestriction patterns of 94% of MRSA isolates from patients, personnel, and the environment associated with a nosocomial outbreak were closely related (similarity coefficient, 85 to 100%). In contrast, methicillin-susceptible S. aureus isolates showed a marked diversity of macrorestriction patterns (median similarity, 41%). MRSA isolates from other geographical areas showed diverse macrorestriction patterns, with the exception of four isolates displaying identical or closely related patterns; these isolates were associated with concurrent outbreaks in four other Belgian hospitals. A concordance of genomic DNA macrorestriction typing with phenotypic methods was observed for 60 to 65% of MRSA isolates, and a concordance with standard DNA restriction analysis was found for 79 to 98% of these isolates. In conclusion, genomic DNA macrorestriction analysis was a useful complement to phenotypic methods for delineating epidemic isolates of MRSA, for identifying their nosocomial reservoirs, and for tracing their intra- and interhospital spread. The genetic relatedness of MRSA isolates, as estimated by this technique, appeared to correlate with their space-time clustering.
为评估表型和基因型分析在耐甲氧西林金黄色葡萄球菌（MRSA）流行病学分型中的作用，我们对来自一家大学医院的64株流行MRSA分离株、10株散发的甲氧西林敏感金黄色葡萄球菌分离株以及来自不同地理区域医院的18株MRSA分离株进行了特征分析。用SstII进行的染色体DNA宏观限制性分析通过脉冲场凝胶电泳进行解析，并与抗菌型分析、噬菌体分型分析以及用BglII进行的标准基因组DNA限制性分析进行比较。这些方法的鉴别能力指数分别为0.982、0.959、0.947和0.959。与医院感染暴发相关的患者、医护人员及环境中的MRSA分离株，94%的宏观限制性图谱密切相关（相似系数为85%至100%）。相比之下，甲氧西林敏感金黄色葡萄球菌分离株的宏观限制性图谱显示出明显的多样性（中位相似性为41%）。来自其他地理区域的MRSA分离株显示出多样的宏观限制性图谱，但有4株分离株呈现相同或密切相关的图谱除外；这些分离株与比利时其他4家医院同时发生的暴发有关。60%至65%的MRSA分离株的基因组DNA宏观限制性分型与表型方法一致，其中79%至98%的分离株与标准DNA限制性分析一致。总之，基因组DNA宏观限制性分析是表型方法的有益补充，可用于描绘MRSA的流行分离株、确定其医院感染源以及追踪其在医院内和医院间的传播。通过该技术估计的MRSA分离株的遗传相关性似乎与其时空聚集相关。
