Division of Epidemiology ICAR- Indian Veterinary Research Institute Bareilly India.
Division of Bacteriology and Mycology ICAR- Indian Veterinary Research Institute Bareilly India.
J Appl Microbiol. 2022 Dec 1;133(6):3490-3501. doi: 10.1111/jam.15781.
E. coli are ubiquitously present bacterial pathogens that cause septicaemia, diarrhoea and other clinical illness in farm animals. Many pathogen factors can be associated with disease conditions. Currently, studies inferring E. coli genetic factors associated with infection in bovines are limited. Hence, the present study envisaged to determine the pathogen genetic factors associated with bovine disease conditions.
The comparative genomic analysis involved genome sequence data of 135 diseased and 145 healthy bovine origin E. coli strains. Phylogroups A and C, as well as pathotypes ExPEC and EPEC, were found to have a strong connection with bovine disease strains. STEC strains, including EHEC, seem to play a less important role in bovine disease. Sequence types (STs) predominant among strains from diarrhoeal origin were ST 301 (CC 165) and ST 342. Correlation of core genome phylogeny with accessory gene-based clustering, phylogroups and pathotypes indicated lineage-specific virulence factors mostly associated with disease conditions.
Comparative genomic analysis was applied to infer genetic factors significant in bovine disease origin E. coli strains. Isolates from bovine disease origin were enriched for the phylogroups A and C, and for the pathotypes ExPEC and EPEC. However, there was minimal evidence of STEC involvement. The study also indicated predominant genetic lineages and virulence genes (pap, sfa and afa) associated with disease origin strains.
The study revealed significant pathotypes, phylogroups, serotypes and sequence types associated with bovine disease conditions. These identified genetic factors can be applied for disease diagnosis, implementing vaccines and therapeutic measures. In addition, E. coli isolates from the bovine species revealed a complex pattern of disease epidemiology.
大肠杆菌是一种普遍存在的细菌性病原体，可导致农场动物的败血症、腹泻和其他临床疾病。许多病原体因素都与疾病状况有关。目前，推断与牛感染相关的大肠杆菌遗传因素的研究有限。因此，本研究旨在确定与牛疾病状况相关的病原体遗传因素。
比较基因组分析涉及 135 株患病和 145 株健康牛源大肠杆菌菌株的基因组序列数据。发现 A 组和 C 组以及 ExPEC 和 EPEC 等血清型与牛病菌株有很强的联系。STEC 菌株，包括 EHEC，似乎在牛病中作用较小。腹泻来源菌株中主要的 ST 型是 ST301（CC165）和 ST342。核心基因组系统发育与附加基因聚类、 phylogroups 和血清型的相关性表明，与疾病状况相关的主要是谱系特异性毒力因子。
应用比较基因组分析推断与牛源大肠杆菌菌株疾病起源相关的遗传因素。来自牛病的分离物富含 A 组和 C 组，以及 ExPEC 和 EPEC 血清型。然而，STEC 的参与证据很少。该研究还表明，与疾病起源菌株相关的主要遗传谱系和毒力基因（pap、sfa 和 afa）。
该研究揭示了与牛病状况相关的重要血清型、phylogroups、血清型和序列型。这些鉴定出的遗传因素可用于疾病诊断、实施疫苗和治疗措施。此外，来自牛种的大肠杆菌分离物显示出复杂的疾病流行病学模式。
