Abstract

Rojan Modaresi, Karim Mardani*, Amir Tukmechi and Abdolghaffar Ownagh

The present study was conducted to determine the prevalence of Listeria spp. in fish obtained from Urmia fish markets. A number of 194 fish comprising Oncorhynchus mykiss (n=42), Sander lucioperca (n=38), Cyprinus carpio (n=30), Hypophthalmiachthys molitrix (n=48), Abramis brama (n=12), Astacus leptodactylus (n=12) and Silurus glanis (n=12) were obtained from different fish markets of Urmia from June 2009 to February 2010. Listeria isolation was performed in two stages including enrichment in cold and selective plating. After colony formation, in order to confirming the genus of the Listeria, a fragment of Prs gene using Listeria genus specific primers was amplified from isolated bacteria using polymerase chain reaction (PCR). Results revealed that Listeria was isolated from 24 fish (12.37%). The highest prevalence of Listeria was observed in both A. brama and A. leptodactylus with 25%, while the lowest prevalence of Listeria was seen in S. lucioperca (9.7%). From the total of 24 Listeria isolates, five isolates (21%) were confirmed to be L. monocytogenes; seven isolates were L. ivonoi (29%) while L. Seeligeri was not isolated from any examined fish. The study showed that L. monocytogenes and other Listeria species are common contaminant of fish obtained from Urmia fish markets, and this may pose serious public health implications.