Widerström Micael, Wiström Johan, Ferry Sven, Karlsson Carina, Monsen Tor
Department of Infectious Diseases, Ostersund Hospital, SE-831 83 Ostersund, Sweden.
J Clin Microbiol. 2007 May;45(5):1561-4. doi: 10.1128/JCM.02071-06. Epub 2007 Mar 7.
Staphylococcus saprophyticus is a common cause of urinary tract infections (UTIs) in women. Little is known about the molecular epidemiology of S. saprophyticus UTIs. In the current study, we compared 76 isolates of S. saprophyticus prospectively isolated from women with uncomplicated UTI participating in a randomized placebo-controlled treatment trial performed in northern Sweden from 1995 to 1997 with 50 strains obtained in 2006 from five different locations in northern Europe with pulsed-field gel electrophoresis (PFGE). The aim was to elucidate the molecular epidemiology of this uropathogenic species and to investigate whether specific clones are associated with UTI in women. A total of 47 different PFGE profiles were detected among the 126 analyzed isolates. Ten clusters consisting of 5 to 12 isolates each showing PFGE DNA similarity of >85% were identified. Several clusters of genetically highly related isolates were detected in the original trial as well as among isolates obtained during 2006 from different locations. In the original trial, clonal persistence was found among 16 of 21 (76%) patients examined in the placebo group at follow-up 8 to 10 days after inclusion, indicating a low spontaneous short-time bacteriological cure rate. We conclude that multiple clones of S. saprophyticus were causing lower UTIs in women. The result suggests that some human-pathogenic clones of S. saprophyticus are spread over large geographical distances and that such clones may persist over long periods of time.
腐生葡萄球菌是女性尿路感染（UTIs）的常见病因。目前对腐生葡萄球菌引起的尿路感染的分子流行病学了解甚少。在本研究中，我们采用脉冲场凝胶电泳（PFGE）技术，将1995年至1997年在瑞典北部进行的一项随机安慰剂对照治疗试验中前瞻性分离出的76株来自患单纯性尿路感染女性的腐生葡萄球菌，与2006年从北欧五个不同地点获得的50株菌株进行了比较。目的是阐明这种尿路致病性菌种的分子流行病学，并调查特定克隆是否与女性尿路感染有关。在126株分析菌株中总共检测到47种不同的PFGE图谱。鉴定出10个簇，每个簇由5至12株菌株组成，显示PFGE DNA相似性>85%。在最初的试验以及2006年从不同地点获得的菌株中均检测到几个遗传高度相关的菌株簇。在最初的试验中，在纳入后8至10天随访时，安慰剂组检查的21名患者中有16名（76%）发现有克隆持续存在，这表明自发短期细菌学治愈率较低。我们得出结论，腐生葡萄球菌的多个克隆导致女性下尿路感染。结果表明，腐生葡萄球菌的一些人类致病克隆在大地理距离上传播，并且这些克隆可能长期持续存在。
