Effect of Streptomyces probiotics on the gut microbiota of Litopenaeus vannamei challenged with Vibrio parahaemolyticus.

José Manuel Mazón‐Suástegui,Milagro García‐Bernal,Joan Sebastian Salas‐Leiva,Ricardo Medina‐Marrero,Ricardo Medina‐García

doi:10.1002/mbo3.967

Abstract

This study assessed the intestinal microbiota of juveniles of the White shrimp Litopenaus vannamei, whose feed was enriched with three probiotic formulations: Streptomyces sp. RL8 (RL8); a mix of Lactobacillus graminis and Streptomyces spp. RL8 and N7 (Lac‐Strep); and a mix of Bacillus spp. and Streptomyces spp. RL8 and N7 (Bac‐Strep). The analysis was performed by sequencing the V3 region of the 16S rRNA gene of treated animals and the control group before and after Vibrio parahaemolyticus challenge. After challenge, the highest Shannon diversity indexes corresponded to RL8 and Bac‐Strep (3.94 ± 0.11 and 3.39 ± 0.3, respectively) and the lowest to the control group (2.58 ± 0.26). The most abundant phyla before and after challenge were Proteobacteria, Actinobacteria, and Bacteroidetes. The principal component analysis and Statistical Analysis of Metagenomic Profiles (STAMP) showed that the gut microbiota of the groups RL8 and Bac‐Strep after challenge was different from the other experimental groups, which was characterized by a higher bacterial diversity, as well as a significant stimulation of the Bacteriovorax population and other antimicrobial producing genera that protected shrimp from infection.

Highlights

The Pacific White shrimp Litopenaeus vannamei is the main shellfish species reared worldwide
The results showed that after challenge, microbiota composition of shrimp treated with RL8 and BacStrep was different from the rest of the experimental groups
Several intestinal functions are achieved through bacterial metabolism, which may benefit the host by improving the immune response, nutrient absorption, and homeostasis maintenance (Hooper & Macpherson, 2010)

Summary

Introduction

The Pacific White shrimp Litopenaeus vannamei is the main shellfish species reared worldwide. Shrimp and microorganisms share the same aquatic medium; the intestinal microbial community interacts directly with planktonic microbiota (De Schryver & Vadstein, 2014; Xiong et al, 2015). Characterization of the intestinal microbiota (IM) of aquatic organisms is a priority to understand host–microorganism interactions and the corresponding relationship with the surrounding microbiota (Gillilland et al, 2012; Roeselers et al, 2011). Numerous strategies have been developed to improve the colonization of the gastrointestinal tract (GIT) of aquatic animals with beneficial bacteria and avoid proliferation of pathogenic bacteria. One of such approaches has been diets with pre-, pro-, and symbiotic supplementation, which can improve animal growth and feed efficiency

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Conclusion