Bacterial Epidemiology and Antimicrobial Resistance Research Unit, U.S. National Poultry Research Center, U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS), Athens, GA, United States.
Hygiene and Zoonoses Department, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
Front Cell Infect Microbiol. 2021 Jul 13;11:681588. doi: 10.3389/fcimb.2021.681588. eCollection 2021.
In this study, multidrug-resistant (MDR) isolates from retail food and humans assigned into similar Multilocus Sequence Types (MLST) were analyzed using whole genome sequencing (WGS). analysis of assembled sequences revealed the existence of multiple resistance genes among the examined isolates. Of the six CTX-M-producing isolates from retail food, was the prevalent variant identified (83.3%, 5/6). Two plasmid-mediated fosfomycin resistance genes, A3, and A4, were detected from retail food isolates (one each from chicken and beef), where A4 was identified in the chicken isolate 82CH that also carried the colistin resistance gene -1. The and A genes in retail food isolates were located adjacent to insertion sequences IS and IS, respectively. Sequence analysis of the reconstructed plasmid (p82CH) showed 96-97% identity to -carrying IncI2 plasmids previously identified in human and food isolates from Egypt. Hierarchical clustering of core genome MLST (HierCC) revealed clustering of chicken isolate 82CH, co-harboring and A4 genes, with a chicken isolate from China at the HC200 level (≤200 core genome allelic differences). As co-harboring and A4 genes has only been recently reported, this study shows rapid spread of this genotype that shares similar genetic structures with regional and international lineages originating from both humans and food animals. Adopting WGS-based surveillance system is warranted to facilitate monitoring the international spread of MDR pathogens.
在这项研究中，对零售食品和人类中的多药耐药（MDR）分离株进行了分析，这些分离株被分配到相似的多位点序列类型（MLST）中，使用了全基因组测序（WGS）。对组装序列的分析揭示了在检查的分离株中存在多种耐药基因。在来自零售食品的 6 株产 CTX-M 的分离株中，发现了一种流行的变体（83.3%，5/6）。从零售食品分离株中检测到两种质粒介导的磷霉素耐药基因 A3 和 A4，其中 A4 存在于携带粘菌素耐药基因 -1 的鸡肉分离株 82CH 中。零售食品分离株中的 和 A 基因分别位于插入序列 IS 和 IS 附近。对重建的 质粒（p82CH）的序列分析表明，与先前在埃及人类和食品分离株中鉴定的携带 -IncI2 质粒具有 96-97%的同一性。核心基因组 MLST（HierCC）的层次聚类显示，同时携带 和 A4 基因的鸡肉分离株 82CH 与来自中国的鸡肉 分离株在 HC200 水平（≤200 个核心基因组等位基因差异）聚类。由于 同时携带 和 A4 基因的情况仅在最近才被报道，因此本研究表明这种基因型的快速传播，该基因型与来自人类和食用动物的区域和国际 谱系具有相似的遗传结构。有必要采用基于 WGS 的监测系统，以促进监测 MDR 病原体的国际传播。
