Changes in the intestinal microbiota of Pacific white shrimp (Litopenaeus vannamei) with different severities of Enterocytozoon hepatopenaei infection

The intestinal microbiota of the Pacific white shrimp Litopenaeus vannamei during Enterocytozoon hepatopenaei (EHP) infection was investigated by 16S rRNA gene-based analysis. The results showed that bacterial diversity in the intestine of L. vannamei was high, but it decreased with increasing severity of EHP infection. The relative abundances of the phyla Planctomycetes, Actinobacteria and Acidobacteria decreased significantly with a decrease in body size or EHP infection severity (P < 0.05). The most abundant genera were Pseudomonas, Methylobacterium, Bradyrhizobium, Bacteroides, Vibrio, Prevotella and so on. In addition, the relative abundances of some bacteria, such as Pseudomonas, Bradyrhizobium, Bacteroides and Vibrio, increased significantly with a decrease in body size or EHP infection severity (P < 0.05). These findings suggest that changes in the intestinal microbiota occur depending on the severity of EHP infection.