Department of Animal Science, University of Tennessee, Knoxville, TN, USA.
Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Osaka, Japan.
Zoonoses Public Health. 2021 May;68(3):213-225. doi: 10.1111/zph.12812. Epub 2021 Feb 2.
Escherichia albertii, often misidentified as Escherichia coli, has become an emerging foodborne human enteric pathogen. However, the prevalence and major animal reservoirs of this significant pathogen are still not clear. Here, we performed comprehensive microbiological, molecular, comparative genomics and animal studies to understand the status and features of E. albertii in the US domestic and food animals. Although no E. albertii was identified in a total of 1,022 diverse E. coli strains isolated from pets and food animals in a retrospective screening, in a pilot study, E. albertii was successfully isolated from a broiler farm (6 out of 20 chickens). The chicken E. albertii isolates showed clonal relationship as indicated by both pulsed-field gel electrophoresis (PFGE) and whole-genome sequence analysis. The isolated chicken E. albertii displayed multidrug resistance; all the resistance determinants including the extended-spectrum beta-lactamase gene, carried by plasmids, could be conjugatively transferred to E. coli, which was further confirmed by S1-PFGE and Southern hybridization. Whole-genome sequence-based phylogenetic analysis showed the chicken E. albertii strains were phylogenetically close to those of human origins. Challenge experiment demonstrated that the E. albertii strains isolated from human and wild bird could successfully colonize in the chicken intestine. Together, this study, for the first time, reported the isolation of E. albertii in poultry at the pre-hrvest level. The findings from multi-tier characterization of the chicken E. albertii strains indicated the importance of chickens as a reservoir for E. albertii. A large scale of E. albertii survey in poultry production at the pre-harvest level is highly warranted in the future.
产酸克雷伯菌，常被误鉴定为大肠杆菌，已成为一种新兴的食源性人类肠道病原体。然而，这种重要病原体的流行情况和主要动物宿主仍不清楚。在这里，我们进行了全面的微生物学、分子学、比较基因组学和动物研究，以了解产酸克雷伯菌在美国国内和食品动物中的状况和特征。虽然在对宠物和食品动物的总共 1022 株不同大肠杆菌菌株进行回顾性筛选中未鉴定出产酸克雷伯菌，但在一项试点研究中，从一个肉鸡养殖场成功分离出了产酸克雷伯菌（20 只鸡中有 6 只）。脉冲场凝胶电泳（PFGE）和全基因组序列分析均表明，鸡中产酸克雷伯菌分离株具有克隆关系。分离出的鸡中产酸克雷伯菌表现出多重耐药性；所有耐药决定因子，包括质粒携带的扩展谱β-内酰胺酶基因，均可通过接合转移到大肠杆菌，这进一步通过 S1-PFGE 和 Southern 杂交得到证实。基于全基因组序列的系统发育分析表明，鸡中产酸克雷伯菌与人类来源的菌株在系统发育上密切相关。攻毒实验表明，从人类和野生鸟类中分离出的产酸克雷伯菌菌株能够成功定植于鸡肠道。总的来说，这项研究首次报道了在禽类生产的收获前水平分离出产酸克雷伯菌。对鸡中产酸克雷伯菌菌株进行多层次特征描述的结果表明，鸡是产酸克雷伯菌的重要宿主之一。在未来，非常有必要在禽类生产的收获前水平上对产酸克雷伯菌进行大规模调查。
