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