Evaluation of the dietary supplementation of autochthonous bacteria on growth, survival and resistance to Aeromonas veronii challenge in Clarias batrachus and Heteropneustes fossilis

Abstract

The study focused on identifying autochthonous bacteria from the indigenous catfish intestine and evaluating their impacts on survival, growth and against Aeromonas veronii infection in Clarias batrachus and Heteropneustes fossilis under laboratory conditions. Candidate bacteria were isolated using Nutrient Agar (NA) and de Man, Rogosa and Sharpe (MRS) agar in duplicate. An immersion technique was employed to determine the biosafety of these isolates in both catfish species at a dose of 107 CFU/mL. Three experimental diets: D1 (basal diet + putative Bacillus sp., 108–109 CFU/g), D2 (basal diet + 3% BioFav Aqua) and D3 (basal diet + putative Lactobacillus sp., 108–109 CFU/g) were prepared to conduct a 4‐week long feeding trial, whereas the control diet received no probiotic supplementation. The probiotic performance was analysed by comparing the growth performance and survival of C. batrachus and H. fossilis. Resistance against Aeromonas veronii infection was determined by a challenge test of catfish. Initially, 16 autochthonous isolates were collected, and among them, an isolate from C. batrachus intestine and another from the gut of H. fossilis were selected for further studies. A series of biochemical analyses identified that the putative bacteria were Bacillus sp. and Lactobacillus sp., respectively. The biosafety test showed no clinical signs of infection or mortality among experimental catfishes. All probiotic‐treated fish showed higher growth increments than control. Incorporation of Bacillus sp. and Lactobacillus sp. in the basal diet significantly (p < 0.05) improved growth and survival in both catfish, where Bacillus sp. showed the best effects in C. batrachus, and Lactobacillus sp. in H. fossilis. Intramuscular (IM) injection with A. veronii revealed that probiotic‐treated fish had better survival rates. The study demonstrated the potentiality of autochthonous bacteria to enhance growth, survival, feed efficiency and immunity and hence recommended as a better health management approach in catfish aquaculture.

Influence of probiotic and prebiotic supplementation on intestinal microbiota and resistance to Edwardsiella ictaluri infection in channel catfish (Ictalurus punctatus) following florfenicol administration

“…Similar work has been done with the walking catfish ( Clarias spp. ), where bacterial strains with activity against pathogens were isolated from the host species of interest (Paul et al., 2022; Prihanto et al., 2020). A challenge with Aeromonas veronii after a feeding trial indicated walking catfish fed the diet containing an autochthonous Bacillus strain had higher survival than fish fed the basal diet (Paul et al., 2022).…”

Bacterial diseases in marine fish species: current trends and future prospects in disease management

“…RCS1, Pantoea agglomerans RCS2, and Bacillus cereus RCS3 (Amenyogbe et al 2022 ). In recent work, Paul et al ( 2022 ) focussed on uncovering native autochthonous bacteria from the catfish gut and assessing their effects on Aeromonas veronii infection in Clarias batrachus , a freshwater fish and Heteropneustes fossilis , a marine fish in a lab setting. All fish treated with probiotics had faster growth rates than controls.…”

Microbial inoculums improve growth and health of Heteropneustes fossilis via biofloc-driven aquaculture

“…In Southeast Asian countries, stinging catfish ( Heteropneustes fossilis ) is a well-known indigenous farmed catfish species, having several health benefiting properties [ 17 ]. With high demand, intensification and commercialisation of indigenous catfish aquaculture, farmers are frequently facing disease outbreaks and heavy mortalities due to microbial infections [ 18 ].…”