Prevalence, virulence factor and antibiotic susceptibility patterns of Salmonella spp. from poultry products in Ardabil province

Contamination of poultry products by Salmonella spp. is an important issue both in the poultry industry and public health. The present study aimed at molecular detection and typing of Salmonella isolated from poultry products. Moreover, antibiotic resistance patterns and the biofilm formation ability of isolates were determined. Eighty poultry product samples were collected from chicken supply and distribution centers. Salmonella spp. were identified by culture as well as the genus-specific PCR. For serological identification, a slide agglutination test using O grouping polyvalent sera was used. BOXAIR and REP-PCR methods were evaluated for the discrimination of Salmonella isolates at the serotype level. Antibiotic susceptibility testing of serotypes against sixteen antibiotics was performed using the standard Kirby-Bauer disc diffusion method. The extent of biofilm formation was measured by the Microtiter-plate biofilm formation assay. From a total of 80 samples, 11 Salmonella spp. were identified which were divided into 2 different serotypes belonging to B and A serogroups. BOX repeat-based PCR (BOXAIR-PCR) and Repetitive element-based PCR (REP-PCR) banding results of isolates revealed 7 and 6 reproducible fingerprint patterns, respectively. The highest resistance was observed in response to ampicillin and doxycycline followed by chloramphenicol, sulfamethoxazole, and trimethoprim, neomycin, nalidixic acid. Multidrug resistance was detected in all Salmonella serotypes. Seven isolates possessed the ability to produce biofilm with varied adhesion strength. These results revealed the high and unexpected prevalence of Salmonella spp. in poultry products with multiple antibiotic resistance and biofilm production ability. Also, BOXAIR and REP-PCR results revealed high diversity in serotypes of Salmonella and subsequently indicate variety in the origin of Salmonella spp.