Institute of Medical Microbiology, Virology and Hygiene,University Hospital, Schillingallee 70, D-18057 Rostock, Germany.
Novartis Vaccines and Diagnostics, Via Fiorentina1, 53100 Siena, Italy.
J Med Microbiol. 2010 Apr;59(Pt 4):442-452. doi: 10.1099/jmm.0.013581-0. Epub 2009 Dec 10.
Streptococcus pyogenes is an important human pathogen for which an association between infection site and selected epidemiological or functional markers has previously been suggested. However, the studies involved often used strains with an insufficiently defined clinical background and laboratory history. Thus, the major goal of the present study was to investigate these relationships in 183 prospectively collected, well-defined, low-passage isolates from a North-East German centre for tertiary care. For each isolate the clinical background (91 respiratory, 71 skin and 21 invasive isolates) and antibiotic-resistance pattern was recorded. All isolates were classified according to their emm type, antibiotic-resistance and PFGE pattern ( SmaI restriction analysis of genomic DNA). As novel discriminatory methods we performed a PCR-based typing of the pilus-protein-encoding FCT region (FCT) and biofilm-formation phenotyping in various culture media. Forty-one isolates were found to be resistant to at least one of the tested antibiotics. emm typing revealed emm28, emm12 , emm1, emm4, emm89 and emm2 as the most frequent types in our collection. The novel FCT typing showed isolates encoding FCT types 4 and 2 to be the most common. Overall 113 strains with unique combinations of emm and FCT types, antibiotic-resistance and PFGE patterns were identified. The majority of all isolates revealed an association of biofilm-formation capacity with growth media. Comparing all results for potential associations, no correlation could be established between the anatomical site of isolation and the emm or the FCT type. There was no relationship between biofilm formation and emm type, antibiotic-resistance or PFGE patterns. However, a novel association between biofilm formation and FCT type became obvious among strains from our collection.
化脓性链球菌是一种重要的人类病原体，先前已经有人提出感染部位与特定的流行病学或功能标志物之间存在关联。然而，所涉及的研究通常使用临床背景和实验室历史记录不够明确的菌株。因此，本研究的主要目标是在东北德国一个三级护理中心前瞻性收集的 183 个明确、低传代的分离株中研究这些关系。记录了每个分离株的临床背景（91 个呼吸道、71 个皮肤和 21 个侵袭性分离株）和抗生素耐药模式。所有分离株均根据其 emm 型、抗生素耐药性和 PFGE 模式（基因组 DNA 的 SmaI 限制分析）进行分类。作为新的鉴别方法，我们对菌毛蛋白编码 FCT 区（FCT）进行了基于 PCR 的分型，并在各种培养基中进行了生物膜形成表型分析。发现 41 个分离株对至少一种测试抗生素具有耐药性。emm 分型显示，在我们的分离株中，emm28、emm12、emm1、emm4、emm89 和 emm2 是最常见的类型。新型 FCT 分型显示，编码 FCT 类型 4 和 2 的分离株最为常见。总共鉴定出 113 株具有独特的 emm 和 FCT 型、抗生素耐药性和 PFGE 模式组合的菌株。我们所有分离株的大多数都显示出生物膜形成能力与生长培养基之间存在关联。比较所有潜在关联的结果，无法确定分离部位与 emm 或 FCT 型之间存在相关性。生物膜形成与 emm 型、抗生素耐药性或 PFGE 模式之间没有关系。然而，在我们的分离株中，生物膜形成与 FCT 型之间出现了一种新的关联。
