Characterization of Enterococcus faecium 10 - 1: A potential probiotic with broad-spectrum anti-Vibrio activity.

Vibrio spp. are ubiquitous in aquatic environments and can infect a broad range of hosts. Consumption of undercooked, Vibrio-contaminated seafood poses a serious threat to human health, frequently causing gastroenteritis, wound infections, and septicemia. Here, we report an Enterococcus faecium strain 10 − 1, which exhibits potent antagonistic activity against a broad spectrum of aquatic pathogenic Vibrio species. Its safety was systematically verified through phenotypic antibiotic resistance screening, as well as whole-genome analysis of virulence factors and mobile genetic elements. The strain displayed broad-spectrum anti-Vibrio activity in vitro, and its active components were remarkably stable after exposure to high temperature (121 °C), extreme pH (2–10), lyophilization–rehydration, and long-term storage at low temperature. Furthermore, E. faecium 10 − 1 exhibited high tolerance to salinity and simulated gastrointestinal stress, underscoring its excellent probiotic potential. Collectively, our results demonstrate that E. faecium 10 − 1 represents a promising candidate probiotic for aquaculture applications, providing a foundation for developing next-generation microbes beneficial for aquatic animal production.