Aquaculture provides a significant proportion of the fish consumed around the world. In West Africa, aquaculture is an important economic sector. However, several diseases with high fish mortality are caused by bacterial infections. Due to the lack of surveillance in aquaculture, this study investigated the presence of bacteria in fish farms. The purpose of the study was to isolate bacteria in aquaculture (Ivory Coast). Two hundred and forty fishes and water samples were collected from the pond of two fish farms. Fish was scraped, then, dissected to collect their gills and intestines. Bacterial culture was done for the detection of many species. Isolate identification was done using biochemical tests (API20E) and MALDI-TOF tests. Also, 1696 bacteria strains were isolated, 70.9% of strains were from the fish organs and 29,1% from the water samples. The higher colonization rate was observed in water and on fish’s surface. No statistical difference was observed between the two farms. Seven major species were isolated in both farms: Escherichia coli, Pseudomonas aeruginosa, Enterobacter hormaechei, Enterococcus faecalis, Citrobacter freundii, Morganella morganii and Bacillus cereus. The major isolated strains were Enterobacter hormachaei, Enterococcus faecalis and Escherichia coli. Multi-resistance for 3 classes of antibiotics was observed in some of those strains. This investigation shows microbiological risks for aquatic animals and humans who are in interaction with fish farms.
Key words: Aquaculture, multidrug-resistant strains, fish, West Africa.