Study on the <i>Nocardia seriolae</i> Antagonistic Bacterium in the Gut Microbiota of <i>Micropterus salmoides</i>.

ABSTRACT: The present study investigates the gut microbiota dynamics of Micropterus salmoides during Nocardia seriolae infection and identifies potential probiotic candidates for disease control in aquaculture. We artificially infected M. salmoides with N. seriolae and analyzed the gut microbiota of dying fish, asymptomatic fish during the peak mortality period, and healthy fish. The results showed that N. seriolae infection significantly altered the gut microbiota diversity. Based on analysis of gut microorganisms, we isolated and identified an N. seriolae-resistant Bacillus from the gut of M. salmoides, which was named B. amyloliquefaciens MS05 (BaMS05). BaMS05 demonstrated significant antibacterial activity against N. seriolae and other common pathogens of M. salmoides both in vitro and in vivo. Additionally, BaMS05 could colonize the gut of M. salmoides for at least five days and exhibited a protective effect against N. seriolae infection, reducing cumulative mortality by 40% at the fifth day. This study provides insights into the role of gut microbiota in disease resistance and highlights BaMS05 as a potential probiotic for preventing and controlling N. seriolae infections in aquaculture. Further research will focus on optimizing the application of BaMS05 and verifying its biosafety for practical use in M. salmoides farming.

SUBMITTER: Xu S 

PROVIDER: S-EPMC12467488 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature