Prevalence and antibiotic resistance of Listeria species in meat products in Ankara, Turkey

In this study, a total of 146 raw (minced, chicken, beef) and cooked (red meat, chicken) meat samples were analysed for the presence of Listeria spp. The isolates were characterized by morphological, cultural, biochemical tests according to Bergeyʹs manual and confirmed by API-Listeria kit. Out of a total of 146 meat samples, 79 (54.10%) were found to be contaminated with Listeria spp., with the highest incidence (86.4%) occurring in raw minced meat. Listeria monocytogenes was isolated from 9 (6.16%) of the 79 samples examined. Other species isolated included L. innocua 68 (46.57%), L. welshimeri one (0.68%) and L. murrayi one (0.68%). Of the Listeria species, L. innocua (46.57%) was the most predominantly isolated species in a variety of meat samples. Overall, the Listeria strains isolated from meat and meat products were mostly resistant to cephalothin and nalidixic acid but exhibited a high degree of susceptibility to kanamycin, chloramphenicol and tetracycline. The importance of finding antibiotic resistant Listeria spp. in food is discussed.