Caracterización metagenómica de cepas resistentes a agentes químicos y su utilidad probiótica contra vibrios parahaemolyticus

Aquaculture suffers significant economic losses in white shrimp (Litopenaeus vannamei) crops due to diseases of microbial and viral origin. Currently, diseases caused by bacteria of the Vibrio genus have gained momentum in shrimp farming systems, and to combat it the use of drugs has generated resistance and diseases. The objective of this research was to study the metagenomic characterization of the microbiota exposed to chemical agents and to verify the sensitivity and probiotic usefulness against vibrios parahaemolyticus in white shrimp (Litopenaeus vannamei). Samples were collected from ozone-treated seawater reservoirs, which were plated on general and specific agars, such as Trypticase soy agar (TSA); Chromagar bacillus (CB) and Man Rugosa Shamr (MRS) and then begin the selection process by incubating for 24 hours at 32°C. Two bacterial consortia were obtained, calling them CN5, RS3, and a biofilm-forming colony, calling it CINV. For the analysis of the samples, the protocol granted by Ilumina for the preparation of libraries in 16S metagenomic sequencing was used, followed by the evaluation of the antagonistic activity by the Kirby-Bauer technique. The results obtained in this study indicate that A rich and complex microbiota was identified, with only 8.7% identified at the species level with a 100% abundance of Bacillus sp, while for the CINV sample there was a 99% abundance of vibrios not present in the database of sequencing. In vitro inhibition tests show that the combination of both microbial consortia had a 99% inhibition rate against V. parahaemolyticus and CINV. This research will serve as a baseline for the study of wild bacteria with antimicrobial capacity, being an advantage unlike several studies in which research is carried out using marine sponges and corals where there are limitations regarding the availability of these organisms.