Comparison the prevalence of Listria monocytogenes in alimentary tract of ordinary carp and phytophagous fish in Tehran & Gilan provinces

Objective: Unfortunately, fish and marine products available in markets are not cleaned and eviscerated (no discharge of viscera and guts). On the other hand, the microbial flora of intestine is a microbial reflection of the water flora used in the culture spot. There is a probability of transmission of contamination of surrounding muscles via viscera and gut. This study aimed to find these bacteria in the intestine of fish via FDA, in pisciculture pools in Tehran and Gilan. Method & Materials: 120 samples of fish were taken from 2 hatchery pools in Gilan and Tehran. The culture medias were: 1) Brain and heart infusion broth, 2) listeria enrichment broth base, 3) listeria selective agar, 4) Nalidixic acid, 5) Kalium thiocyanat. We blend the alimentary canal of ordinary caro and phytophagous fish in a blender that include 225 ml of brain and heart infusion broth. Then 1ml of this mixture transferred to the tubes which have 9ml of listeria enrichment broth base. 0.1ml of listeria enrichment broth base transferred on listeria selective agar. other tests were: superficial tests, biochemical and subtraction. Results & Conclusion: Only 4 samples (6.6%) were geram positive in term of Listria monocytogen serotype 4/b. The amount of contamination in the studied fish was the same, 2 cases in carp fish and 2 cases in phytophagous. The contaminated samples were only in Gilan Province and the reason might be high pollution of pisciculture pools in Gilan Province and /or low temperature microbial in this province in comparison to Tehran Province.

کلیدواژه ها:

Listria monocytogenes ، Ordinary Carp ، Phytophagous