Investigating the prevalence of resistance genes in Listeria monocytogenes isolated from food and clinical samples

Background: Listeriosis can be fatal for vulnerable groups of society. The disease has been widespread in recent years due to the large consumption of dairy and meat products. There is little information about the susceptibility of antibiotics and the pattern of Listeria monostigenesis gene resistance in Iranian society. Accordingly, the present study was conducted to investigate the antibiotic susceptibility and genetic resistance pattern of Listeria monosteogenesis strains isolated from different clinical and environmental sources. Materials and methods: In this study, 55 isolates were tested for antibiotic susceptibility by disk diffusion in agar and genetic pattern by polymerase chain reaction (PCR). Results: 91% and 83% of the strains were resistant to streptomycin and Trimethoprim/sulfamethoxazole respectively. The result of PCR of antibiotic resistance genes showed that the prevalence of ermA, ermB, strA, tetA, tetS and ermC genes in isolates of Listeria monocytogenes was 50.90% (28/55), 21.81% (12/55), 89.9% (49/55), 0% (0/55), 21.81% (12/55) and 0% (0/55), respectively. Conclusion: Due to the presence of 1/2a and 1/2c serotypes in isolated isolates and the presence of marker virulence genes in these strains, these isolates have potential for biological risks and listeriosis disease. Existence of this genetic pattern and resistance pattern can be partly due to the use of antibiotics during the production of dairy products. Regarding results of this study, the manner and rate of using animal antibiotics can be managed.