Isolation and characterization of vibriophage vB_Vc_SrVc9: an effective agent in preventing Vibrio campbellii infections in brine shrimp nauplii (Artemia franciscana).

AIMS: This study describes the physicochemical and genomic characterization of phage vB_Vc_SrVc9 and its potential for phage therapy application against a pathogenic Vibrio campbellii strain. METHODS AND RESULTS: A lytic phage vB_Vc_SrVc9 against V. campbellii was isolated from shrimp farm sediment, and characterized physicochemical and genomically. The use of vB_Vc_SrVc9 phage increased the survival in brine shrimp Artemia franciscana and reduced presumptive V. campbellii to nondetectable numbers. Genomic analysis showed a genome with a single contig of 43·15 kb, with 49 predicted genes and no tRNAs, capable of recognizing and generating complete inhibition zones of three Vibrio sp. CONCLUSIONS: To our knowledge vB_Vc_SrVc9 is a lytic phage that could be used against Vibrio infections, reducing vibrio presence without any apparent impact over the natural microbiota at the family level in 28 libraries tested. SIGNIFICANCE AND IMPACT OF THE STUDY: vB_Vc_SrVC9 is a novel phage and ecofriendly alternative for therapeutic applications and biotechnological purposes because is stable at different environmental conditions, has the potential to eliminate several strains, and has a short latent period with a good burst size. Therefore, the use of phages, which are natural killers of bacteria, represents a promising strategy to reduce the mortality of farmed organisms caused by pathogenic bacteria.

Isolation of Vibrio and Pseudomonas from brown shrimp (Penaeus californiensis Holmes) intestine.

Bacteria of the genera Vibrio, Pseudomonas and Aeromonas were isolated from the intestine of apparently healthy brown shrimp (Penaeus californiensis Holmes) cultured in a tidal pond. Species from these genera of bacteria have been reported as shrimp pathogens and have been involved in human gastrointestinal disorders related to seafood consumption. Isolation was done first in Marine broth, then in selective media (TCBS, Cetrimide and MacConkey). The oxidase negative strains were discarded as insignificant to shrimp culture. The identification of oxidase positive strains was based in morphological and colonial characteristics, biochemical capabilities, and both salinity and temperature tolerance. API 20E system and fatty acid analysis were also included. Three potentially pathogenic bacteria, Vibrio parahaemolyticus, Vibrio furnissii and Pseudomonas putida were isolated and identified from healthy shrimp intestine.