Antibiotic and Bacteriocin Sensitivity of Listeria monocytogenes Strains Isolated from Different Foods

This study aimed to determine the antibiotic and bacteriocin sensitivity of Listeria monocytogenes strains isolated from animal derived foods. With disc diffusion assay, all fourteen L. monocytogenes strains were susceptible to the antibiotics, including penicillin G, vancomycin, tetracycline, chloramphenicol, rifampicin, erythromycin, gentamicin and trimethoprim. However, the percentages of fosfomycin and streptomycin resistances were 92.9% and 7.1%, respectively. Multiple resistances were not observed among the tested strains. The results of well diffusion assays showed that all strains were inhibited by the cell-free supernatant of a bacteriocin-producing strain, Pediococcus acidilactici 13, with the inhibition zones ranging from 16.00 to 24.50 mm. These results provide useful information on antibiotic resistance of L. monocytogenes strains isolated from foods, and can potentially be used to develop bacteriocin-based interventions to guard against the hazards associated with L. monocytogenes in ready-to-eat meat and poultry products.