Shrimp farming is an extremely important sector in food production worldwide, and it is considered that the biggest problem it faces are disease outbreaks. Various infections are attributed to the genus Vibrio, which cause significant mortalities (up to 100%) from the early days of shrimp culture (SENASICA, 2018). Within this bacterial genus, exists highly toxigenic strains capable of producing a binary toxin PirAB, which primarily affects the shrimp hepatopancreas. (Cuéllar-Anjel, 2013). The objective of the present study is to determine the presence of toxigenic Vibrio parahaemolyticus in white shrimp post-larvae collected from transport tanks.
Post-larvae samples were collected from 26 containers, 12 from Sonora (Hatcheries LA, LC and LE), and 14 from Sinaloa (Hatcheries LB, LD and LF). Vibrio spp. strains were isolated and purified from a homogenate of postlarvae in 2% NaCl solution using specific media. The molecular diagnostic of purified strains was carried out with real-time PCR (IQ REAL AH; and molecular identification of strains by partial amplification and sequencing of the 16S rRNA.
A total of 21 colonies of presumptive V. parahaemolyticus were obtained, however, by PCR only five strains were confirmed (toxin gen carriers). In addition, the molecular identification revealed a high identity of the species V. parahaemolyticus (1 strain) and V. campbellii (3 strains).
The shrimp post-larvae analyzed, despite not showing apparent signs of infection, were carriers of the toxigenic agent Vibrio spp. Additionally, the molecular identification shows high affinity with V. parahaemolyticus and V. campbellii. It is recommended to reinforce the surveillance and health analysis of shrimp broodstock and larvae production in hatcheries.