引言：产超广谱β-内酰胺酶（ESBL）的大肠杆菌已在食品生产动物中广泛存在。这些菌株是抗生素耐药性基因（ARGs）的库，并可能成为人类的感染源，因为传播可能通过直接或间接接触发生。
方法：本研究调查了津巴布韦2年（2017-2019年）家禽粪便中产ESBL和耐粘菌素大肠杆菌的携带情况。利用国家大肠杆菌监测计划的表型易感性测试结果，从国家微生物参考实验室生物库中的动物大肠杆菌分离株中选择了来自家禽泄殖腔标本的21个ESBL阳性分离株进行全基因组测序，以提供不同地理区域和分离年份的代表性。从1号农场和2号农场的3000只肉鸡活禽身上采集了泄殖腔拭子，并对40只后院鸡和10只鸭子进行了采样。根据临床实验室标准协会指南进行抗菌药物敏感性和ESBL测试。产ESBL分离株的全基因组测序用于确定序列类型（ST）、ARG和门组。
结果：21个大肠杆菌分离株被确认为ESBL产生菌。鉴定了三种确定的序列型克隆复合物（CC）（ST10CC、ST155CC和ST23CC），其中ST10CC与最具抗生素耐药性的谱相关。ESBL表型与头孢噻肟-Munich-14（CTX-M-14）或CTX-M-79的存在有关。已鉴定的质粒介导的喹诺酮类耐药性决定簇为qnrB19和qnrS1，并且来自1号农场肉鸡的一个ST10CC分离株携带可移动粘菌素耐药性基因（mcr-1）。大多数已鉴定的系统发育类群为B1、A和未知类群。
讨论：产生禽ESBL的大肠杆菌属于一组不同的菌株。几种ARG的检测突显了实施强化控制措施以限制在动物、环境和人类中传播的重要性。这是mcr-1在津巴布韦的第一份报告，进一步强调了“一个健康”方法对控制AMR传播和发展的重要性。
Introduction: Extended spectrum beta-lactamase (ESBL) producing Escherichia coli have become widespread among food producing animals. These strains serve as a reservoir of antibiotic resistance genes (ARGs) and act as a possible source of infection to humans as transmission can occur by direct or indirect contact.

Methods: This study investigated the faecal carriage of ESBL producing and colistin resistant E. coli in poultry over a 2-year period (2017-2019) from Zimbabwe. A total of 21 ESBL positive isolates from poultry cloacal specimens were selected for whole genome sequencing from animal E. coli isolates bio-banked at the National Microbiology Reference laboratory using phenotypic susceptibility testing results from the National Escherichia coli Surveillance Program to provide representation of different geographical regions and year of isolation. Cloacal swabs were collected from 3000 broiler live birds from farm 1 and from farm 2, 40 backyard chickens and 10 ducks were sampled. Antimicrobial susceptibility and ESBL testing were performed as per Clinical Laboratory Standards Institute guidelines. Whole genome sequencing of ESBL producing isolates was used to determine sequence types (STs), ARGs, and phylogroups.

Results: Twenty-one of the included E. coli isolates were confirmed as ESBL producers. Three defined sequence type clonal complexes (CCs) were identified (ST10CC, ST155CC and ST23CC), with ST10CC associated with the most antibiotic resistant profile. The ESBL phenotype was linked to the presence of either cefotaximase-Munich-14 (CTX-M-14) or CTX-M-79. Plasmid mediated quinolone resistant determinants identified were qnrB19 and qnrS1 and one ST10CC isolate from farm 1 broiler chickens harbored a mobile colistin resistance gene (mcr-1). Phylogenetic groups most identified were B1, A and unknown.

Discussions: The avian ESBL producing E. coli belonged to a diverse group of strains. The detection of several ARGs highlights the importance of implementing enhanced control measures to limit the spread in animals, environment, and humans. This is the first report of mcr-1 in Zimbabwe, which further underscores the importance of the One Health approach to control the spread and development of AMR.

https://www.frontiersin.org/articles/10.3389/fcimb.2022.1035145/full?utm_source=dlvr.it&utm_medium=twitter