Detection of moulds and their toxins in fresh water fish

This study was firstly aimed to screen the contamination of fresh water fish by moulds and their mycotoxins of two commonly consumed fish species in Egypt,Tilapia nilotica and Mugil cephalus. Secondly, an experimental trial to investigate the antifungal effect of natamycin on Tilapia nilotica. A total of 200 fish samples including Tilapia nilotica and Mugil cephalus, (100 of each) were randomly collected from various shops and supermarkets.The collected samples were examined mycologically. Tilapia nilotica and Mugil cephalus samples showed average mould counts of 3.82×102 ± 2.41× 10 CFU/g and 1.85×102 ± 4.33× 10 CFU/g,respectively.Seven and five species were isolated from Tilapia nilotica and Mugil cephalus,respectively. The extreme prevalent fungal species isolated from the examined samples was Aspergillus flavus. The study declared that total aflatoxins levels of Tilapia nilotica and Mugil cephalus showed average of 1.67 ± 0.26 ppb and 2.78 ± 0.39 ppb,respectively. On the other hand,natamycin showed significant antifungal properties in a concentration- dependent manner. For instances, natamycin 2.5g/L significantly reduced total mould count (77.09%).