Genetic Diversity of Intimin Gene of Atypical Enteropathogenic Escherichia coli Isolated from Human, Animals and Raw Meats in China.
Genetic Diversity of Intimin Gene of Atypical Enteropathogenic Escherichia coli Isolated from Human, Animals and Raw Meats in China.
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中国人、动物及生肉中非典型致病性大肠杆菌Intimin基因的遗传多样性
DOI：
10.1371/journal.pone.0152571
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Xiong Y
中科院分区：
文献类型：
--
作者：
Xu Y;Bai X;Zhao A;Zhang W;Ba P;Liu K;Jin Y;Wang H;Guo Q;Sun H;Xu J;Xiong Y
非典型肠致病性大肠杆菌（aEPEC）被认为是一种新兴的肠道病原体，在发展中国家和发达国家比典型EPEC更普遍。粘附因子intimin是aEPEC的主要粘附因子，是由eae编码的一种外膜蛋白，在aEPEC的发病机制中起着关键作用。本研究调查了中国143株aEPEC的intimin亚型分布和多态性，这些aEPEC来自于中国的腹泻患者、健康携带者、动物和生肉。这些aEPEC菌株分属于71个不同的血清型，其中O型52个，H型24个。共检测到68种不同的eae基因型和19种intimin亚型。分别从86名乳腺癌患者、14名健康携带者、19只动物和24个生肉菌株中鉴定出18、8、7和5种intimin亚型。Intimin β1亚型在肺炎患者和动物中的检出率分别为34.88%和47.37%。eae-β1在牙周炎患者和健康者中的分布差异有统计学意义（P = 0.004）。Intimin-θ在生肉菌株中的优势率（50%）高于腹泻患者菌株（12.79%，P = 0.0003）、健康携带者菌株（7.14%，P = 0.007）和动物菌株（15.79%，P = 0.020）。两种主要亚型（eae-β1和eae-θ）具有相当多的多态性，但在4种来源中无显著差异。PFGE分析显示119个不同的模式，菌株被聚成11个组，相似性指数从63%到100%。这些结果表明，在中国，来自不同来源的aEPEC菌株具有高度异质性。动物和生肉是具有遗传多样性的肠内寄生菌的重要来源，它们可能是这些细菌的重要传播媒介。
Atypical enteropathogenic Escherichia coli (aEPEC) is considered to be an emerging enteropathogen that is more prevalent than typical EPEC in developing and developed countries. The major adherence factor, intimin, an outer membrane protein encoded by eae, plays a pivotal role in the pathogenesis of aEPEC. This study investigated the distribution and polymorphisms of intimin subtypes of 143 aEPEC strains from diarrheal patients, healthy carriers, animals, and raw meats in China. These aEPEC strains belonged to more than 71 different serotypes, which comprised 52 O serogroups and 24 H types. Sixty-eight different eae genotypes and 19 intimin subtypes were detected. Eighteen, eight, seven, and five intimin subtypes were identified from 86 diarrheal patients, 14 healthy carriers, 19 animals, and 24 raw meats strains, respectively. Intimin β1 was the most prevalent subtype in strains from diarrheal patients (34.88%) and animals (47.37%). There was a statistically significant difference in the distribution of eae-β1 between diarrheal patients and healthy carriers (P = 0.004). Intimin-θ was more predominant among raw meat strains (50%) than among diarrheal patients strains (12.79%, P = 0.0003), healthy carrier strains (7.14%, P = 0.007), or animal strains (15.79%, P = 0.020). The two predominant subtypes (eae-β1 and eae-θ) had considerable polymorphisms with no significant differences among the four sources. PFGE analysis revealed 119 distinct patterns and the strains were clustered into 11 groups with similarity indices ranging from 63% to 100%. These results suggest that in China, aEPEC strains from different sources are highly heterogeneous. Animals and raw meats are important sources of genetically diverse intimin-harboring aEPEC, which might serve as important transmission vehicles of these bacteria.