Protection of juvenile Penaeus indicus from Vibrio parahaemolyticus infection by Bacillus subtilis

Objective: The objective of present study was to investigate the potential probiotic properties of Bacillus subtilis in Penaeus indicus. Method & Materials: Bacillus subtilis bacterium isolated from intestine of P. indicus juveniles were added to pelleted feed as a probiotic at level 1010 cfu/g feed by soaking method. After 60 days feeding trial with Bacillus supplemented and non-supplemented control feeds, P. indicus from 0.429± 0.014g exhibited significant differences (P<0.05), between Bacillus and control groups in growth and survival. Sixty days after the start of the Bacillus feeding, the prawns were challenged by bath exposure to Vibrio parahaemolyticus (107 cell/ ml), for 28 days. Results & Conclusion: Two weeks after challenging, cumulative mortality was significantly (P<0.05) reduced in probiotic treated group. Probiotic treated group had 88.33% survival rate; whereas the control group had only 20.83% survival. In addition, the control group had an unhealthy external appearance, while treated group prawn, appeared healthy and normal. From this, it was concluded that the selected Bacillus sp. may be a promising probiotic to protect P. indicus from infection with Vibrio parahaemolyticus.

کلیدواژه ها:

Penaeus indicus ، Probiotic ، Challenge test ، Vibrio parahaemolyticus infection