Assesstment of mould contamination of Tilapia nilotica and Mugil cephalus fish and trials to reduce using natamycin

Abstract

Contamination of fish by fungi is considered one of the most serious causes of losses in aquaculture. Therefore, our study was firstly aimed to screen the fungal status 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 60 fish samples including Tilapia nilotica and Mugil cephalus (30 of each) were randomly collected from various retail markets and shops at dissimilar sanitation levels at Kafrelsheikh Governorate, Egypt during the winter season, 2018. All samples were examined for fungal contamination. Tilapia nilotica and Mugil cephalus samples showed average mould counts of 3.63×102 and 1.65×102 CFU/g, respectively. Nine fungal species were isolated from two fish species. Seven and five species were isolated from Tilapia nilotica Mugil cephalus, respectively. The highest prevalent fungal species isolated from the two fish was Aspergillus flavus. Natamycin showed significant antifungal properties in a concentration- dependent manner. Thus, efficient hygienic handling, rapid cooling of fish can reduce the fungal contamination of fish. In addition, we highly recommend soaking or spraying fish with natamycin solution as an efficient strategy in reducing the fungal load of raw fish.