Assessment of Antagonistic Activities of Probiotic Bacteria Against Pathogenic Vibrio Spp. in Vitro and in Vivo in Shrimp Larvae

Abstract

Nowadays, probiotics attract the attention of scientists because of their versatile antimicrobial activity and established health benefits on the host. In this study, three most farmer-used commercial probiotics (Super Biotic, Zymetin & Aqua Clear-S) were selected to analyse the antagonistic activity against Vibrio spp. for evaluating effective antagonism of probiotic against pathogenic Vibrio spp. Shrimp hatchery owners and farmers often face Vibrio spp. attacks in larval conditions and want to use probiotics to prevent these pathogenic microbes. For in vitro and in vivo tests, disc diffusion tests and challenge tests in liquid media were conducted. The disc diffusion test revealed that the growth area of Vibrio spp. in the presence of Super Biotic was the lowest. The Vibrio spp. concentrations in this study were considered as 10⁶ CFU/mL in an in vivo challenge test with shrimp larvae. Probiotic co-culture was done at 37°C and incubated for 24 hours. In the in vivo challenge test, 50% mortality occurred in the positive control group on the 4th day, and among three probiotic treatment groups, the highest (31.65%) mortality occurred in the treatment group with Aqua Clear-S, and the lowest mortality (16.67%) in the treatment group with Super Biotic. So, it has been found that in both in vitro and in vivo conditions, commercial probiotic Super Biotic resisted the growth of Vibrio spp. more than Zymetin or Aqua Clear-S.