Surveillance of antimicrobial resistance, phenotypic, and genotypic patterns of Salmonella enterica isolated from animal feedstuffs: Annual study

Abstract

Background and Aim: Salmonellosis is a significant foodborne disease that causes serious illness in the gastrointestinal of humans and it is a public health problem worldwide. This study aimed to determine Salmonella spp. in animal feeds, its characteristic, serovar identification, genotyping, and drug sensitivity. Materials and Methods: Salmonella spp. from animal feedstuffs was collected from January 1 to December 31, 2017, with 657 samples. Serogroup classification was performed by using the slide agglutination test. Then, the samples were analyzed for genotype patterns using pulsed-field gel electrophoresis (PFGE) for DNA fingerprint and antibiotic sensitivity by Vitek® 2 techniques. Results: A total of 80 samples (12.17 %) were found to be Salmonella positive; commercial feed compounds of 60 samples (75%); soybean meal of 10 samples (12.5%); pork meal of 5 samples (6.25%); a fish meal of three samples (3.75%) and poultry meal of 2 samples (2.5%). Serogroups B, C, D, and E were found in this study; 8 samples (10%), 39 samples (48.75%), 8 samples (10%), and 13 samples (16.25%), respectively. A total of 12 samples (15%) were not determined by serogrouping. The most common serovars were Salmonella Rissen (10%), Salmonella Mbandaka (8.75%), and Salmonella Livingstone (6.25%), which belong to serogroup C. Nine of eleven pulsotypes were detected when analyzed by PFGE, showed similarity index between 40.8 and 100 %. Antimicrobial susceptibility tests by Vitek® 2 compact for 11 strains were classified into three groups: resistance to 4, 8, and 11 antibiotics, out of 20 antibiotics. Conclusion: This study revealed annual variation of Salmonella spp. Serovar, genotype, and phenotype from commercial feed compounds and raw materials of which involved people must be aware.