Anti-QS mediated anti-infection efficacy of probiotic culture-supernatant against Vibrio campbellii infection and the identification of active compounds through in vitro and in silico analyses

Abstract

The main intent of the present study was to identify the novel anti-quorum sensing (anti-QS) compounds from probiotic product (Rhodomax) and assess their anti-infection effect of against Vibrio campbellii infection using tomato clownfish (Amphiprion frenatus). In this study, rhodomax probiotic-product was investigated for its active compounds’ prediction through in silico analysis. Initially, anti-QS activity of probiotic-supernatant was authenticated by decrease in bioluminescence production of V. campbellii. As expected, the probiotic-supernatant effectively inhibited the biofilm formation, swimming motility, and hydrophobicity of V. campbellii at 20 μg/ml concentration. During in vivo trail with tomato clownfish, probiotic-supernatant (20 ppm) treatment showed a significant increase in the survival rates to the level of 88% against V. campbellii infection. Further, the reduced colonization of V. campbellii inside the probiotic-supernatant treated animals correlates the anti-infection activity. The histopathological differences in tissue levels such as the gill, intestine, and kidney of infected and probiotic-supernatant treated animals were also support the in-vivo trial, which strongly revealed the disease protection of rhodomax-supernatant against V. campbellii infection. Notably, the docking analysis revealed that the anti-QS mediated anti-infection activity of rhodomax-supernatant against V. campbellii infection is accomplished by the presence of active metabolites such as,4-Dihydro-7-methoxy-2,2-dimethyl-2H-1-benzopyran-3,4-diol and Pyrrolo(1,2-a)pyrazine-1,4-dione, hexahydro-3-(1-methylethyl). Hence, we suggest that these two active metabolites could be the novel alternative agents to control V. campbellii-associated infections in aquaculture.