Genomic analysis of shiga toxin-containing Escherichia coli O157:H7 isolated from Argentinean cattle.
Genomic analysis of shiga toxin-containing Escherichia coli O157:H7 isolated from Argentinean cattle.
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从阿根廷牛分离的含志毒素的大肠杆菌O157：H7的基因组分析。
DOI：
10.1371/journal.pone.0258753
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发表时间：
2021
期刊：
影响因子：
3.7
通讯作者：
Cataldi A
中科院分区：
文献类型：
--
作者：
Amadio A;Bono JL;Irazoqui M;Larzábal M;Marques da Silva W;Eberhardt MF;Riviere NA;Gally D;Manning SD;Cataldi A
牛是肠出血性大肠杆菌（EHEC）的主要宿主，其独特的血清型为O157:H7。肠出血性大肠杆菌是一种严重的全身性疾病溶血性尿毒症综合征（HUS）的主要病原体。阿根廷是全世界儿童溶血性尿毒综合征发病率最高的国家，每10万名儿童中有12-14例。在此，我们评估了从阿根廷潮湿的潘帕斯草原的牛身上回收的EHEC O157:H7分离株的基因组。根据系统发育研究，EHEC O157可分为几个支系。进化枝8株被列为高毒株。该分支的大多数菌株具有志贺毒素stx2a-stx2c基因型。为了更好地了解EHEC O157:H7的毒力、致病性和进化相关的分子基础，我们通过全基因组测序对这些分离株进行了比较基因组分析。分类为进化枝8（4株）和进化枝6（4株）的分离株每个基因组含有13 ~ 16个羔羊样前噬菌体，并对观察到的前噬菌体变异进行了分析。菌株间比较表明，虽然一些噬菌体高度相关，可以归为科，但其他噬菌体是独特的。编码stx2a的噬菌体多样性较高，编码stx2c的噬菌体则较为保守。在进化枝8中发现的一组基因包含13个基因，这些基因主要编码DNA结合蛋白。在所研究的菌株中，Q抗菌剂、Q- Stx2a基因间区以及前噬菌体复制蛋白的O和P γ等位基因的多态性与不同水平的Stx2a产生有关。正如预期的那样，所有菌株都具有高度保守的pO157质粒，尽管一株菌株在蛋白酶EspP基因中显示转座子中断。这一基因组分析可能有助于了解在阿根廷牛中传播的EHEC O157:H7株高毒力的遗传基础。这项工作与其他种群中O157菌株变异的其他研究一致，这些研究显示了编码stx2a的噬菌体的关键差异。
Cattle are the main reservoir of Enterohemorrhagic Escherichia coli (EHEC), with O157:H7 the distinctive serotype. EHEC is the main causative agent of a severe systemic disease, Hemolytic Uremic Syndrome (HUS). Argentina has the highest pediatric HUS incidence worldwide with 12–14 cases per 100,000 children. Herein, we assessed the genomes of EHEC O157:H7 isolates recovered from cattle in the humid Pampas of Argentina. According to phylogenetic studies, EHEC O157 can be divided into clades. Clade 8 strains that were classified as hypervirulent. Most of the strains of this clade have a Shiga toxin stx2a-stx2c genotype. To better understand the molecular bases related to virulence, pathogenicity and evolution of EHEC O157:H7, we performed a comparative genomic analysis of these isolates through whole genome sequencing. The isolates classified as clade 8 (four strains) and clade 6 (four strains) contained 13 to 16 lambdoid prophages per genome, and the observed variability of prophages was analysed. An inter strain comparison show that while some prophages are highly related and can be grouped into families, other are unique. Prophages encoding for stx2a were highly diverse, while those encoding for stx2c were conserved. A cluster of genes exclusively found in clade 8 contained 13 genes that mostly encoded for DNA binding proteins. In the studied strains, polymorphisms in Q antiterminator, the Q-stx2A intergenic region and the O and P γ alleles of prophage replication proteins are associated with different levels of Stx2a production. As expected, all strains had the pO157 plasmid that was highly conserved, although one strain displayed a transposon interruption in the protease EspP gene. This genomic analysis may contribute to the understanding of the genetic basis of the hypervirulence of EHEC O157:H7 strains circulating in Argentine cattle. This work aligns with other studies of O157 strain variation in other populations that shows key differences in Stx2a-encoding prophages.
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影响因子：
5.8
作者：
Abbott, JC;Aanensen, DM;Spratt, BG
通讯作者：
Spratt, BG
影响因子：
3.1
作者：
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影响因子：
3.7
作者：
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作者：
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作者：
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