College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, China.
College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450002, China.
Poult Sci. 2023 Jun;102(6):102640. doi: 10.1016/j.psj.2023.102640. Epub 2023 Mar 9.
This study was designed to depict prevalence and antimicrobial resistance characteristics of Proteus mirabilis (P. mirabilis) strains in 4 chicken farms and to probe the transfer mechanism of resistance genes. A total of 187 P. mirabilis isolates were isolated from 4 chicken farms. The susceptibility testing of these isolates to 14 antimicrobials showed that the multidrug resistance (MDR) rate was as high as 100%. The β-lactamase resistance genes bla, bla, bla and colistin resistance gene mcr-1 were highly carried in the P. mirabilis isolates. An MDR strain W47 was selected for whole genome sequencing (WGS) and conjugation experiment. The results showed that W47 carried 23 resistance genes and 64 virulence genes, and an SXT/R391 integrated conjugative elements (ICEs) named ICEPmiChn5 carrying 17 genes was identified in chromosome. ICEPmiChn5 was able to be excised from the chromosome of W47 forming a circular intermediate, but repeated conjugation experiments were unsuccessful. Among 187 P. mirabilis isolates, 144 (77.01%, 144/187) isolates carried ICEPmiChn5-like ICEs, suggesting that ICEs may be the major vector for the transmission of resistance genes among MDR chicken P. mirabilis strains in this study. The findings were conducive to insight into the resistance mechanism of chicken P. mirabilis strains and provide a theoretical basis for the use of antibiotics for the treatment of MDR P. mirabilis infections in veterinary clinic.
本研究旨在描绘 4 个鸡场中奇异变形杆菌（P. mirabilis）菌株的流行情况和抗菌药物耐药特征，并探讨耐药基因的转移机制。从 4 个鸡场共分离出 187 株奇异变形杆菌。这些分离株对 14 种抗菌药物的药敏试验显示，其多重耐药（MDR）率高达 100%。β-内酰胺酶耐药基因 blaTEM、blaCTX-M、blaOXA 和粘菌素耐药基因 mcr-1 在奇异变形杆菌分离株中携带率较高。选择一株 MDR 菌株 W47 进行全基因组测序（WGS）和接合实验。结果表明，W47 携带 23 个耐药基因和 64 个毒力基因，在染色体上发现了一个命名为 ICEPmiChn5 的 SXT/R391 整合性接合元件（ICE），携带 17 个基因。ICEPmiChn5 能够从 W47 的染色体上切除形成一个环状中间体，但重复的接合实验未能成功。在 187 株奇异变形杆菌分离株中，有 144 株（77.01%，144/187）携带 ICEPmiChn5 样 ICEs，表明 ICEs 可能是本研究中鸡源 MDR 奇异变形杆菌菌株耐药基因传播的主要载体。这些发现有助于深入了解鸡奇异变形杆菌菌株的耐药机制，并为兽医临床治疗 MDR 奇异变形杆菌感染时抗生素的使用提供理论依据。
