Prevalence of food contamination with Listeria spp. in Kermanshah, Islamic Republic of Iran

ABSTRACT

Listeria monocytogenes is a human pathogen causing serious diseases. We aimed to determine food contamination with Listeria spp. in Kermanshah, Islamic Republic of Iran. Samples [185 dairy, 187 meat products and 158 ready-to-eat foods such as salads] were randomly collected from markets. After processing, samples were cultured in half-Fraser and Fraser broth followed by cultivation on PALCAM and Oxford media. Confirmatory tests including carbohydrate utilization were performed on isolates to determine species. Bacteria were isolated from 66/530 samples [12.5%]. Meat products showed the highest [27.2%] and dairy products the lowest [3.8%] contamination rates. L. innocua was found in 56 [10.6%] samples, but L. monocytogenes was only found in 3 samples [0.6%]. The results indicate that the rate of contamination with L. monocytogenes, even for ready-to-eat foods, was low but for other Listeria spp., in particular strains of L. innocua, the rate of contamination was higher, suggesting that more control on food sanitation is required