Characterization of antimicrobial resistance and virulence genes of Pseudomonas aeruginosa isolated from mink in China, 2011-2020.

Pseudomonas aeruginosa strains are potential pathogens that cause respiratory diseases in minks, and caused serious economic loss to mink breeding industry. In this study, we identified antimicrobial resistance and virulence genes in 125 P. aeruginosa isolates from mink in China from 2011 to 2020. The results showed at least one mutation in the gyrA (Thr83Val or Asp87Gly) and parC (Ser87 Leu) genes as well as single mutations in 56 isolates. At least 4-fold reductions in the fluoroquinolone minimum inhibitory concentration values were found when tested in the presence of PAβN in 23 isolates, while 44 isolates were positive for the extended spectrum β-lactamases and 15 antibiotic resistance genes were identified in this population with a prevalence between 1-32%, including qnrA, CTX-M-1G, ermB and C, cmlA, flor, catl, intl1, tetA, B, C, and D as well as sul1, 2, and 3 genes. Interestingly, one isolate carried ten resistance genes. Five virulence genes were detected, where exoS and algD were the most frequently detected (76.8%), which were followed by plcH (76%), lasB (73.6%), and pilB (31.2%). The isolates carrying the antibiotic resistance or virulence genes were genetically variable, suggesting a horizontal spread through the population. Hence, this study provides novel and important data on the resistance and pathogenicity of P. aeruginosa in farmed mink infections. These data provide important insights into the mechanism of fluoroquinolone resistance in P. aeruginosa, highlighting its usefulness in the treatment and control of P. aeruginosa infections in minks.