Isolation and characterization of pathogenic bacteria from angel fish

Objective: Infections of aquarium fishes are of importance, because of their commercial impacts. Water and food decontamination procedures are necessary for inhibition of bacterial, protozoan, fungal and viral infections. In the present study the bacterial infections in aquarium angel fish and the treatment protocol was investigated. Method & Materials: Angle fish samples with less feeding, weakness and mucus secretions on the body were tested for bacterial infections. The body of the fishes were completely degraded and suspended in sterile distilled water. The diluted suspensions enriched in the tripticase soy broth (TSB) and inoculated to the tripticase soy agar (TSA) media. The isolated bacteria were purified and characterized by biochemical diagnostic tests. Antimicrobial susceptibility testing (AST) performed via agar diffusion method. Results & Conclusion: Three different colonies isolated in TSA medium. The gram staining and identification of isolated bacteria showed gram-positive rods (Bacillus megaterium), gram-positive cocci (Streptococcus sp.) and gram-negative coccobacilli (Proteus mirabilis). The effect of 15 antibiotics on the isolated bacteria showed different susceptibility outlines for every isolated species. Cefixim, gentamycin and amoxicillin showed the inhibition zone of growth over 2 mm for all three isolated bacteria. The antibiotics cefixime, gentamycin and amoxicillin were effective against all three isolated bacteria among the other antibiotics. These antibiotics recommended as selected agents for beginning of the treatment, before identification of the infectious disease agents, only for sick fishes. The three isolated bacteria contained pathogenic bacteria, are the probable agents for the symptoms in the sample fishes. The infection of healthy fishes was controlled by cleaning proceedings such as water filtration, isolation of new fishes before entering to the aquarium, hand washing post working in an aquarium and before entering the second aquarium and disinfection of tools after using. These procedures recommended for protection of angel fishes from every infectious agent.

کلیدواژه ها:

Angel fish ، bacterial infection ، antimicrobial susceptibility testing