Characterization and distribution of Salmonella spp. isolated from poultry slaughterhouse-processing in Shandong Province.

Salmonella spp.is the most important food-borne pathogens of public health interest incriminated in poultry meat worldwide. The purpose of this study to estimate the prevalence Salmonella spp. contamination in poultry products from 12 different located geographical areas from among the 12 poultry slaughterhouses authorized in China and to characterize all the isolates by serotypes, PFGE patterns, MLST patterns and antimicrobial susceptibility. The prevalence of Salmonella spp. in the poultry slaughterhouse was 10.4%. All 100 strains of Salmonella spp. comprising 13 majority serotypes were identified. S. Enteritidis was the most frequently isolated from samples. The isolates displayed resistance to sulfisoxazole (SF) (79.0%), doxycycline (DOX) (68.0%), tetracycline (TE) (65.0%), florfenicol (FFC) (64.0%), ampicillin (AM) (50.0%), gentamicin (GM) (48.0%), trimethoprim-sulfamethoxazole (SXT) (30.0%), spectinomycin (SPT) (30.0%), enrofloxacin (ENR) (10.0%), ofloxacin (NOR) (10.0%), amoxicillin potassium clavulanat (AC) (1.0%) and polymyxin (PME) (4.0%). The Salmonella spp. isolates were not resistant to cefotaxime (EFT). Each isolates were multi-drug resistant as they were resistant to at least 2 groups of antimicrobials. Four clusters and 38 fingerprint-patterns generated by PFGE were identified among strains recovered from various locations, providing information on associations among the strains as well as evidence of the existence of persistent strains in some areas. MLST analysis of isolates identified the 10 STs, the 7 housekeeping genes had the different variation.