Research Unit in Microbial Food Safety and Antimicrobial Resistance, Department of Veterinary Public Health, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand.
Department of Veterinary Medicine, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand.
Sci Rep. 2022 Feb 14;12(1):2466. doi: 10.1038/s41598-022-06415-0.
This study aimed to determine the percentage of colistin resistant and ESBL-producing Escherichia coli from clinically sick and healthy pigs and understand the molecular mechanisms underlying colistin resistance and ESBL production. A total of 454 E. coli isolates from healthy pigs (n = 354; piglets, n = 83; fattening pigs, n = 142 and sows, n = 100) and sick pigs (n = 100) were examined for antimicrobial susceptibility, chromosomal and plasmid-mediated colistin resistance mechanisms and ESBL genes. The healthy (41%) and sick pig (73%) isolates were commonly resistant to colistin. Three mcr genes including mcr-1 (10.4%), mcr-2 (1.1%) and mcr-3 (45%) were detected, of which mcr-3 was most frequently detected in the healthy (33%) and sick pig (57%) isolates. Coexistence of mcr-1/mcr-3 and mcr-2/mcr-3 was observed in piglets (23%), fattening pig (3.5%) and sick pig (13%) isolates. Three amino acid substitutions including E106A and G144S in PmrA and V161G in PmrB were observed only in colistin-resistant isolates carrying mcr-3. The percentage of ESBL-producing E. coli was significantly higher in the sick pigs (44%) than the healthy pigs (19.2%) (P = 0.00). The bla group was most prevalent (98.5%), of which bla (54.5%) and bla (42.9%) were predominant. The bla (68.8%) and bla (6.3%) genes were identified in ESBL-producers. All ESBL producers were multidrug resistant and the majority from piglets (97%), fattening pigs (77.3%) and sick pigs (82%) carried mcr gene (s). ESBL producers from piglets (n = 5) and sick pig (n = 1) simultaneously transferred bla (or bla) and mcr-3 to Salmonella. In conclusion, pigs are important reservoirs of colistin-resistant E. coli that also produced ESBLs, highlighting the need for prudent and effective use of antimicrobials in pigs and other food-producing animals.
本研究旨在确定来自临床患病和健康猪的多粘菌素耐药和产 ESBL 的大肠杆菌的百分比，并了解多粘菌素耐药和产 ESBL 的分子机制。共检测了来自健康猪（n=354；仔猪，n=83；育肥猪，n=142；母猪，n=100）和患病猪（n=100）的 454 株大肠杆菌对抗菌药物的敏感性、染色体和质粒介导的多粘菌素耐药机制和 ESBL 基因。健康（41%）和患病（73%）分离株通常对多粘菌素耐药。检测到三种 mcr 基因，包括 mcr-1（10.4%）、mcr-2（1.1%）和 mcr-3（45%），其中 mcr-3 在健康（33%）和患病猪（57%）分离株中最常检测到。在仔猪（23%）、育肥猪（3.5%）和患病猪（13%）分离株中观察到 mcr-1/mcr-3 和 mcr-2/mcr-3 的共存。仅在携带 mcr-3 的多粘菌素耐药分离株中观察到 PmrA 中的 E106A 和 G144S 以及 PmrB 中的 V161G 三种氨基酸取代。在患病猪（44%）中，产 ESBL 的大肠杆菌的百分比明显高于健康猪（19.2%）（P=0.00）。bla 组最为普遍（98.5%），其中 bla（54.5%）和 bla（42.9%）占主导地位。在 ESBL 生产者中鉴定出 bla（68.8%）和 bla（6.3%）基因。所有 ESBL 生产者均为多药耐药，其中大多数来自仔猪（97%）、育肥猪（77.3%）和患病猪（82%）携带 mcr 基因（s）。来自仔猪（n=5）和患病猪（n=1）的 ESBL 生产者同时将 bla（或 bla）和 mcr-3 转移到沙门氏菌。总之，猪是多粘菌素耐药和产 ESBL 的大肠杆菌的重要储存库，这突显了在猪和其他食用动物中谨慎和有效使用抗菌药物的必要性。
