Identification of pathogenic bacteria from diseased nile tilapia Oreochromis niloticus with their sensitivity to antibiotics

Nile Tilapia (Oreochromis niloticus) is an important aquaculture resource that represents one of the most popular cultured species in the whole world. However, culture of this species face some problems, which are associated with the occurrence of pathogenic bacteria and cause high pecuniary loss. The main aim of this study was to isolate and identify the pathogenic bacteria from diseased farmed O. niloticus and to detect the antibiotic sensitivity with some commonly used antibiotics. Bacteria samples were collected from different parts of the body of both diseased and fresh tilapia and cultured in both nutrient agar and broth media. The bacterial colonies were evaluated using biochemical tests i.e. Gram‟s staining, Motility test, Carbohydrate fermentation test, Indole test, MR-VP test and Catalase test.