Characteristics of Shigatoxin-Producing Escherichia coli Strains Isolated during 2010-2014 from Human Infections in Switzerland.
Characteristics of Shigatoxin-Producing Escherichia coli Strains Isolated during 2010-2014 from Human Infections in Switzerland.
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DOI：
10.3389/fmicb.2017.01471
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发表时间：
2017
影响因子：
5.2
通讯作者：
Stephan R
中科院分区：
文献类型：
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作者：
Fierz L;Cernela N;Hauser E;Nüesch-Inderbinen M;Stephan R
目的：本研究的目的是对 2010 年至 2014 年期间从瑞士人类患者中分离出的 95 株产志贺毒素大肠杆菌 (STEC) 进行表征。方法：我们进行了 O 和 H 血清分型和分子亚型分型。结果：五个最常见的血清群是 O157、O145、O26、O103 和 O146。在95个菌株中，35个（36.8％）仅携带stx1基因，43个菌株（45.2％）携带stx2，17个（17.9％）携带stx1和stx2基因的组合。 Stx1a（42 株）和 stx2a（32 株）是最常检测到的 stx 亚型。分别在 70.5%、83.2%、74.7% 和 20% 的菌株中检测到 intimin (eae)、溶血素 (hly)、铁调节粘附 (iha) 和枯草杆菌酶细胞毒素亚型 subAB1、subAB2-1、subAB2-2 或 subAB2-3 的基因。多位点序列分型将大多数 (58.9%) 分离株分配给 5 个不同的克隆复合体 (CC)，分别为 11、32、29、20 和 165。 CC11 包括所有 O157:[H7] 和 O55:[H7] 分离株。 CC32 包含 O145:[H28] 分离株，O145:[H25] 属于序列类型 (ST) 342。CC29 包含 O26:[H11]、O111:[H8] 和 O118:[Hnt] 血清群的分离株，CC20 包含 O51:H49/[Hnt] 和 O103:[H2] 分离株。 CC165 包括 O80:[H2]-ST301 型分离株，全部含有 stx2d、eae-Ψ、hly，66.7% 还含有 iha。所有 O80:[H2]-ST301 菌株均含有至少 7 个由 pS88 携带的基因，pS88 是一种与肠外毒力相关的质粒。与瑞士 2000-2009 年的数据相比，非 O157 STEC 感染的比例有所增加，而 STEC O146 感染的比例也有所增加。相比之下，高毒力的德国克隆 STEC O26:[H11]-ST29 的流行率从 2000-2009 年期间的 11.3% 下降到 2010-2014 年期间的 1.1%。 O80:[H2]-ST301 含有 stx2d、eae-Ψ、hly、iha 和 pS88 相关基因的检测表明瑞士正在出现一种不寻常的高致病性 STEC 血清型。结论：临床 STEC 的血清分型和分子分型表明，尽管 STEC O157 在从患病人类分离的 STEC 中占主导地位，但瑞士非 O157 STEC 感染正在增加，包括由含有 subAB 变体的 STEC O146:[H2/H21/H28]-ST442/ST738 引起的感染，以及最近出现的 STEC O80:[H2]-ST301 含有 eae-Ψ 和 pS88 相关的肠外致病毒力基因。
Objectives: The aim of this study was to characterize a collection of 95 Shigatoxin-producing E.coli (STEC) isolated from human patients in Switzerland during 2010–2014. Methods: We performed O and H serotyping and molecular subtyping. Results: The five most common serogroups were O157, O145, O26, O103, and O146. Of the 95 strains, 35 (36.8%) carried stx1 genes only, 43 strains (45.2%) carried stx2 and 17 (17.9%) harbored combinations of stx1 and stx2 genes. Stx1a (42 strains) and stx2a (32 strains) were the most frequently detected stx subtypes. Genes for intimin (eae), hemolysin (hly), iron-regulated adhesion (iha), and the subtilase cytotoxin subtypes subAB1, subAB2-1, subAB2-2, or subAB2-3 were detected in 70.5, 83.2, 74.7, and 20% of the strains, respectively. Multilocus sequence typing assigned the majority (58.9%) of the isolates to five different clonal complexes (CC), 11, 32, 29, 20, and 165, respectively. CC11 included all O157:[H7] and O55:[H7] isolates. CC32 comprised O145:[H28] isolates, and O145:[H25] belonged to sequence type (ST) 342. CC29 contained isolates of the O26:[H11], O111:[H8] and O118:[Hnt] serogroups, and CC20 encompassed isolates of O51:H49/[Hnt] and O103:[H2]. CC165 included isolates typed O80:[H2]-ST301, all harboring stx2d, eae-ξ, hly, and 66.7% additionally harboring iha. All O80:[H2]-ST301 strains harbored at least 7 genes carried by pS88, a plasmid associated with extraintestinal virulence. Compared to data from Switzerland from the years 2000–2009, an increase of the proportion of non-O157 STEC infections was observed as well as an increase of infections due to STEC O146. By contrast, the prevalence of the highly virulent German clone STEC O26:[H11]-ST29 decreased from 11.3% during 2000–2009 to 1.1% for the time span 2010–2014. The detection of O80:[H2]-ST301 harboring stx2d, eae-ξ, hly, iha, and pS88 related genes suggests an ongoing emergence in Switzerland of an unusual, highly pathogenic STEC serotype. Conclusions: Serotyping and molecular subtyping of clinical STEC demonstrate that although STEC O157 predominates among STEC isolated from diseased humans, non-O157 STEC infections are increasing in Switzerland, including those due to STEC O146:[H2/H21/H28]-ST442/ST738 harboring subAB variants, and the recently emerged STEC O80:[H2]-ST301 harboring eae-ξ and pS88 associated extraintestinal pathogenic virulence genes.