In vitro and in vivo inhibition of Vibrio spp. isolated from the shrimp Litopenaeus vannamei using native lactic acid bacteria

The diseases caused by Vibrio spp. cause the greatest economic losses in shrimp farming, antibiotic therapy has led to the emergence of resistant strains and research is being carried out into the use of probiotics for their treatment. This research aimed to obtain native lactic acid bacteria (LAB) isolated from cultured shrimp and to determine their probiotic potential against antibiotic resistant Vibrio spp in vitro and in vivo. Nine strains of both LAB and Vibrio spp. were isolated from cultured shrimps from Tumbes. Antibiotic–resistance of Vibrio spp. was determined; as well as the in vitro inhibitory power of LAB strains against these strains by agar well trial and in vivo, by experimental infection of shrimp with Vibrio spp. strains and treatment for eight days with LAB strains added to feed. The nine strains of Vibrio spp. isolated from cultured shrimps were resistant to fosfomycin and nalidixic acid, with a multiple antibiotic resistance index (MAR) of 0.2. In the in vitro trial, the C1L, F1L and F3L strains inhibited the largest number of Vibrio spp. strains; also in vivo, the C1L and F1L strains significantly (p < 0.05) increased survival and decreased the Vibrio spp. count of infected shrimp in the hepatopancreas. It is concluded that antibiotic- resistant strains of Vibrio spp. isolated from cultured shrimps could be inhibited by native LAB strains, C1L and F1L, demonstrating a promising probiotic potential.