Expression of Curli by Escherichia coli O157:H7 Strains Isolated from Patients during Outbreaks Is Different from Similar Strains Isolated from Leafy Green Production Environments
Expression of Curli by Escherichia coli O157:H7 Strains Isolated from Patients during Outbreaks Is Different from Similar Strains Isolated from Leafy Green Production Environments
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疫情期间从患者体内分离的大肠杆菌 O157:H7 菌株表达的 Curli 与从绿叶生产环境中分离的类似菌株不同
DOI：
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发表时间：
2016
影响因子：
5.7
通讯作者：
M. Cooley
中科院分区：
文献类型：
--
作者：
S. Ravva;C. Sarreal;M. Cooley
我们以前报道，大肠杆菌O157：H7（EcO157）的菌株，在严峻的土壤环境中生存时间较长，缺乏表达curli，一个健身性状与肠道定植。此外，EcO157的卷曲阳性变异体的比例随着反复的土壤暴露而降低。在这里，我们评估了来自美国爆发和散发感染的84和176个临床菌株，以及211个动物粪便和环境菌株的curli表达。这些志贺菌基因型菌株来自328个不同的基因型，其特征在于多位点可变数目串联重复序列分析（MLVA）。超过一半的粪便菌株（人类和动物）和一个显着比例的环境分离株（82%）被发现缺乏curli表达。与食用受污染的苹果汁、农产品、汉堡包、牛排和牛肉有关的几次爆发中的EcO 157菌株也被发现缺乏curli表达。粪便菌株的系统发育分析表明curli表达分布在整个种群中。然而，与人粪便分离株（58%）相比，显著比例的动物粪便分离株（84%）没有curli表达。此外，环境分离株的分析表明，几乎排他性的curli表达的最小生成树的一个分支的聚类。这表明curli的表达主要取决于环境暴露的类型和隔离源，虽然基因型差异也有助于curli的克隆变异。此外，卷曲缺陷型似乎是一个选择性性状的生存EcO157在农业环境中。
We previously reported that the strains of Escherichia coli O157:H7 (EcO157) that survived longer in austere soil environment lacked expression of curli, a fitness trait linked with intestinal colonization. In addition, the proportion of curli-positive variants of EcO157 decreased with repeated soil exposure. Here we evaluated 84 and 176 clinical strains from outbreaks and sporadic infections in the US, plus 211 animal fecal and environmental strains for curli expression. These shiga-toxigenic strains were from 328 different genotypes, as characterized by multi-locus variable-number tandem-repeat analysis (MLVA). More than half of the fecal strains (human and animal) and a significant proportion of environmental isolates (82%) were found to lack curli expression. EcO157 strains from several outbreaks linked with the consumption of contaminated apple juice, produce, hamburgers, steak, and beef were also found to lack curli expression. Phylogenetic analysis of fecal strains indicates curli expression is distributed throughout the population. However, a significant proportion of animal fecal isolates (84%) gave no curli expression compared to human fecal isolates (58%). In addition, analysis of environmental isolates indicated nearly exclusive clustering of curli expression to a single branch of the minimal spanning tree. This indicates that curli expression depends primarily upon the type of environmental exposure and the isolation source, although genotypic differences also contribute to clonal variation in curli. Furthermore, curli-deficient phenotype appears to be a selective trait for survival of EcO157 in agricultural environments.
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影响因子：
3.7
作者：
Reichhardt C;Jacobson AN;Maher MC;Uang J;McCrate OA;Eckart M;Cegelski L
通讯作者：
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影响因子：
15.9
作者：
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作者：
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通讯作者：
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DOI：
10.1016/j.bbamcr.2013.09.010
发表时间：
2014-08
影响因子：
5.1
作者：
Evans, Margery L.;Chapman, Matthew R.
通讯作者：
Chapman, Matthew R.
影响因子：
3.8
作者：
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