Listeria monocytogenes from different sources: The serotyping, genotyping, virulotyping, and antibiotic susceptibilities of the recovered isolates

It was aimed at serotyping, genotyping, determining various virulence genes, and investigating antibiotic susceptibilities of Listeria monocytogenes isolates recovered from different sources in the current study. For this purpose, a total of 70 L. monocytogenes isolates including 22 chicken, 20 fish, 18 sheep, and 10 cattle origin were used. Polymerase Chain Reaction (PCR) was performed for serotyping and analysis of virulence genes of the isolates, and also Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR was performed for the genotyping. In addition, it was determined the susceptibilities of the isolates against nine different antibiotics via the disk diffusion method. As a result of serotyping, the most detected serogroup in analyzed L. monocytogenes isolates was 1/2a-3a (44.3 %), and but the least detected serogroup 1/2b-3b-7 (11.4 %). ERIC-PCR results revealed a total of 18 different patterns. All isolates were positive for the presence of inlA, inlB, inlC, iap, prfA, actA, hly, plcA, plcB and mpl virulence genes tested. The prevalence of the actA gene in isolates was determined as 70 %. Antibiotic resistance was detected against six antibiotics, and high resistance to oxacillin (80 %) and ciprofloxacin (65.7 %) in the isolates. Furthermore, the rate of multi-drug resistance in L. monocytogenes isolates was 28.5 % (20/70). In conclusion, the present study showed that the sources may pose a potential health risk, according to obtained data on the virulence gene prevalence, serogroup distribution, high genetic heterogeneity, and antibiotic resistance profiles of L. monocytogenes isolates from different sources.