Gut bacterial diversity of wild and cultured penaeus vannamei

Abstract

The pacific white shrimp, Penaeus vannamei is a marine crustacean which has economic importance in the world market. To ensure sustainability of the shrimp industry, production capacity and disease outbreak prevention must be improved. Understanding healthy microbial balance inside the shrimp gut and Hepatopancreas can provide a benchmark study and facilitates to adapt better farming practices. Gut micro biome of cultured and wild P vannamei were analyzed and obtained eight bacterial isolates from the former and four from the latter. Out of the eight isolates obtained from the gut of cultured shrimp, four isolates were identified as Vibrio tubiashii, Vibrio gazogenes, Vibrio proteolyticus, Vibrio natriegens and the remaining from Hepatopancreas (HP) were identified as Vibrio ordalii, Vibrio harveyi, Vibrio parahaemolyticus and Corynebacterium kutscheri. Four types of bacterial isolates were obtained from the wild shrimp, out of them two gut isolates were identified as Vibrio vulnificus, Vibrio furnissii and the remaining isolates from hepatopancreas were identified as Lactobacillus fermentum and Staphylococcus aureus. All the 12 isolates were subjected to antibiotic sensitivity tests and found that Ciprofloxacin (Cf) showed highest inhibitory zone (34mm) against Vibrio harveyi and Norfloxacin (NX) showed lowest (10) mm against Vibrio vulnificus. All the 12 bacterial isolates were resistant to penicillin-G. Ampicillin showed inhibitory activity against Vibrio harveyi and rest of the isolates were resistant. Vibrio tubiashii was resistant to Ampicillin, Furadazole, Penciling-G, and chloramphenicol.