Characterization and virulence factors distribution of bla CTX‐M and mcr‐1 carrying Escherichia coli isolates from bovine mastitis

作者：Muhammad Shafiq, Jinhu Huang, Jayal Shah, Xingliang Wang, Sudais Rahman, Ilyas Ali, L. Chen, Liangliang Wang · 发表于：Journal of Applied Microbiology · 年份：2021 · DOI：10.1111/jam.14994 · 被引用次数：21 · 研究领域：Antibiotic Resistance in Bacteria、Bacteriophages and microbial interactions、Mycobacterium research and diagnosis

Aim To investigate the occurrence of ESBL and colistin-resistant E. coli and its genotypic characterization and identification of virulence determinants in cases of bovine mastitis in three provinces of China. Materials and methods Five hundred and thirty-five milk samples presenting mastitis symptoms were screened for the presence of ESBL, colistin-resistant and different virulence genes. Susceptibility testing was identified by the micro-dilution method. Escherichia coli isolates were used to detect ESBL genes (blaCTX-M, blaSHV and blaTEM) and colistin-resistant genes mcr-(1–9). Multiplex PCR approach was used for the detection of major blaCTX-M groups, different phylogroups and virulence genes. The clonal relationship was then evaluated with MLST, MLSA and PFGE. Results Multi-drug resistance (MDR) was found in more than 85% of ESBL and colistin-resistant E. coli isolates. Genotypic characterization showed a dominance of the blaCTX-M-1 group, and the most prevalent alleles observed were blaCTX-M-28 (38·37%), blaCTX-M-14 (17·44%), blaCTX-M-66 (13·95%) and blaCTX-M-55 (10·46%). The targeted virulence genes were detected in 97·89% of isolates. Sequence types ST58 and ST410 were the most predominant (2/20 = 20%). The majority of the E. coli isolates carrying ESBL and mcr-1 were clonally unrelated. Conclusion High level of association was observed between ESBL-producing and COL-resistance in E. coli of bovine mastitis. Significance and Impact of the Study To the best of our know...