Bacterial diversity and community composition in the gut and rearing water of Pacific White shrimp Penaeus vannamei during an outbreak of white feces disease

Abstract

White feces disease (WFD) recently appeared in white shrimp (Penaeus vannamei) production. Researchers conducted several studies to analyze the differences in gut microbiota between healthy and diseased shrimp, especially in the case of WFD. This study was conducted to compare the diversity and relative abundance of intestinal microbial communities and rearing water, histopathology of intestinal organs, and performance of shrimp production in the emergence of WFD. The gut microbiota and rearing water of white shrimp were investigated by high-throughput/next-generation sequencing. Sequencing preparation included extraction of intestinal genomic DNA and water samples, PCR amplification, quantification and mixing of PCR products, PCR product purification, and library preparation. Observational variables included bioinformatics analysis, intestinal histopathology, feed conversion ratio (FCR), and survival rate (SR). Results showed that the shrimp and rearing water samples during the WFD outbreak exhibited changes in the bacterial community structure. An increase in the abundance of pathogenic bacteria occurred, especially Vibrio sp., in shrimp intestine and rearing water during the WFD outbreak. The dominance of the genus Rubritalea in the WFD-infected shrimp intestine sample was believed to be a trigger for the decreased bacterial diversity in the shrimp intestine. The diversity and relative abundance of bacteria were higher in the intestines of normal shrimp than in those infected with WFD. The WFD-infected shrimp intestine also demonstrated intestinal tissue damage compared with normal shrimp intestine tissue. Regarding production performance at the end of maintenance, the SR and FCR values in WFD-infected ponds were lower than those in normal ponds.