White spot syndrome virus impact on the expression of immune genes and gut microbiome of black tiger shrimp Penaeus monodon

The gut microbiome plays an essential role in the immune system of invertebrates and vertebrates. Pre and pro-biotics could enhance the shrimp immune system by increasing the phenoloxidase (PO), prophenoloxidase (ProPO), and superoxide dismutase activities. During viral infection, the host immune system alteration could influence the gut microbiome composition and probably lead to other pathogenic infections. Since the JAK/STAT pathway is involved in white spot syndrome virus (WSSV) infection, we investigated the intestine immune genes of STAT-silenced shrimp. During WSSV infection, expression levels of Pm Vago1, Pm Doral, and Pm Spätzle in Pm STAT-silenced shrimp were higher than normal. In addition, the transcription levels of antimicrobial peptides, including crustin Pm 1, crustin Pm 7, and Pm PEN3, were higher in WSSV-challenged Pm STAT-silenced shrimp than the WSSV-infected normal shrimp. Meanwhile, Pm STAT silencing suppressed Pm ProPO1, Pm ProPO2, and Pm PPAE1 expressions during WSSV infection. The microbiota from four shrimp tested groups (control group, WSSV-infected, Pm STAT-silenced, and Pm STAT-silenced infected by WSSV) was significantly different, with decreasing richness and diversity due to WSSV infection. The relative abundance of Bacteroidetes, Actinobacteria , and Planctomycetes was reduced in WSSV-challenged shrimp. However, at the species level, P. damselae, a pathogen to human and marine animals, significantly increased in WSSV-challenged shrimp. In constrast, Shewanella algae , a shrimp probiotic, was decreased in WSSV groups. In addition, the microbiota structure between control and Pm STAT-silenced shrimp was significantly different, suggesting the importance of STAT to maintain the homeostasis interaction with the microbiota.