Characterization of multidrug-resistant Proteus mirabilis isolated from chicken carcasses.

This study investigated genotypic and phenotypic features of antimicrobial resistance of Proteus mirabilis isolated from chicken products. Resistance to a broad spectrum of antimicrobial agents was commonly observed in the test isolates: tetracycline (100%), sulfamethoxazole (80%), chloramphenicol (66%), nalidixic acid (66%), ampicillin (60%), streptomycin (56%), ciprofloxacin (52%), kanamycin (46%), gentamicin (38%), ceftriaxone (36%), cefotaxime (34%), ceftiofur (22%), and amoxicillin-clavulanic acid (16%). The β-lactamases TEM-1 and OXA-1, and extended-spectrum β-lactamases CTX-M-9 and CMY-2 were detected in β-lactam-resistant isolates. Single mutations in gyrA and parC were found to be contributing factors for fluoroquinolone resistance. Plasmid-mediated quinolone resistance (PMQR) genes qnrA and qnrD were detected in six fluoroquinolone-resistant isolates and a superintegron element, SXT, was detected in 14 out of 50 isolates. The high-level of antimicrobial resistance of P. mirabilis isolated from food products may pose a potential threat to public health.