Biological Characteristics and Antibiotic Resistance of Proteus mirabilis Isolated from Poultry Slaughterhouses in Xinjiang,China

Abstract

Proteus mirabilis is a significant foodborne pathogen that can be transmitted through the poultry slaughter and processing chain, posing a potential threat to human health. This study aimed to assess the prevalence, antibiotic resistance, contamination potential, and presence of key virulence factors in Proteus mirabilis isolates from poultry slaughterhouses in Xinjiang. A total of 845 samples were collected during poultry slaughtering and processing, from which 95 strains of Proteus mirabilis were isolated and identified, yielding an overall detection rate of 11.24% (95/845). Analysis of interspecies differences revealed that the detection rate of chicken-derived Proteus mirabilis was significantly higher than that of pigeon-derived isolates. Antibiotic susceptibility testing showed the highest resistance rates to tetracycline (87.37%, 83/95), followed by sulfisoxazole (72.63%, 69/95). The proportion of drug-resistant strains was significantly greater in chicken-derived isolates (82.05%, 32/39) compared with pigeon-derived isolates (32.14%, 18/56). Swarming ability assays indicated that 85.26% (81/95) of the strains exhibited swarming ability, with 64.20% (52/81) demonstrating strong swarming ability, suggesting a higher risk of transmission along with the slaughter and processing chain. Additionally, 39 chicken-derived isolates with strong antibiotic resistance were selected for biofilm formation assays; all were capable of biofilm production, with 66.67% (26/39) classified as strong biofilm producers. Detection of antibiotic resistance genes revealed significantly higher prevalence of aac, aad, sul1, and sul2 genes in chicken-derived isolates compared with pigeon-derived isolates (p < 0.0001). Virulence gene map shows that all isolates carried the core virulence genes ureC and hmpA, with chicken-derived isolates generally harboring a greater number of virulence genes than pigeon-derived isolates. These findings highlight the high prevalence, strong contamination potential, and elevated pathogenic risk associated with chicken-derived Proteus mirabilis, underscoring the need to optimize hygiene management in poultry slaughterhouses, enhance monitoring of antibiotic usage, and develop targeted pathogen control strategies.