摘要
      健康家禽可能是肠外致病性大肠杆菌（ExPEC）的宿主，其中一些大肠杆菌可能对抗菌药物具有多药耐药性。这些ExPEC菌株可能会污染环境和/或食物链，从而带来食品安全和人类健康风险。然而，很少有研究表明禽源抗微生物（AMR）ExPEC在人类中的毒力。本研究对AMR-ExPEC进行了表征，并在秀丽隐杆线虫感染模型中研究了它们的一些分离株的毒力潜力。对来自家禽（鸡，n=29；火鸡，n=12）、零售肉类和鸡粪（n=4）或人类（n=1）的46个大肠杆菌分离株进行了测序，并鉴定为ExPEC。除8株外，其余38株ExPEC分离株均对至少一种抗生素具有耐药性，并携带相应的抗微生物耐药性基因（ARGs）。46个ExPEC分离株中约有27个具有多重耐药性（≥3类抗生素）。来自鸡肉或火鸡肉的7个ExPEC分离物具有血清型O25:H4和序列型（ST）131，其与来自具有相同血清型和ST的人类尿路感染（UTI）病例的分离物聚集。使用八个研究的携带各种ARG和毒力基因（VG）的ExPEC分离株的秀丽隐杆线虫挑战模型表明，无论它们在测试的禽肉和粪便中的ARG或VG数量如何，ExPEC都显著缩短了线虫的寿命（P<0.05），与人类UTI分离株相似。这项研究表明了零售禽肉或粪便中AMR-ExPEC的致病潜力，但需要更多的研究来确定其在家禽和人类中的毒力。此外，这些大肠杆菌分离株的特异性抗性谱和/或VGs与其致病性之间的关系值得研究。
Abstract
Healthy poultry can be a reservoir for extraintestinal pathogenic Escherichia coli (ExPEC), some of which could be multidrug resistant to antimicrobials. These ExPEC strains could contaminate the environment and/or food chain representing thus, food safety and human health risk. However, few studies have shown the virulence of poultry-source antimicrobial-resistant (AMR) ExPEC in humans. This study characterized AMR ExPEC and investigated the virulence potential of some of their isolates in a Caenorhabditis elegans infection model. A total of 46 E. coli isolates from poultry (chicken, n = 29; turkey, n = 12) retail meats and chicken feces (n = 4), or humans (n = 1) were sequenced and identified as ExPEC. Except eight, all remaining 38 ExPEC isolates were resistant to at least one antibiotic and carried corresponding antimicrobial resistance genes (ARGs). About 27 of the 46 ExPEC isolates were multidrug-resistant (≥3 antibiotic classes). Seven ExPEC isolates from chicken or turkey meats were of serotype O25:H4 and sequence type (ST) 131 which clustered with an isolate from a human urinary tract infection (UTI) case having the same serotype and ST. The C. elegans challenge model using eight of studied ExPEC isolates harboring various ARGs and virulence genes (VGs) showed that regardless of their ARG or VG numbers in tested poultry meat and feces, ExPEC significantly reduced the life span of the nematode (P < 0.05) similarly to a human UTI isolate. This study indicated the pathogenic potential of AMR ExPEC from retail poultry meat or feces, but more studies are warranted to establish their virulence in poultry and human. Furthermore, relationships between specific resistance profiles and/or VGs in these E. coli isolates for their pathogenicity deserve investigations.

https://www.sciencedirect.com/science/article/pii/S0362028X22000084