Transcriptomic insights into the resistance mechanism of Penaeus vannamei against highly lethal Vibrio parahaemolyticus

Highly lethal Vibrio disease (HLVD) caused by a virulent strain of Vibrio parahaemolyticus (Vp_HLVD), which poses a significant threat to Penaeus vannamei post-larvae, leads to substantial mortality and economic losses. To address this challenge, researchers have recently isolated a highly disease-resistant strain of P. vannamei shrimp. However, the underlying mechanisms that could improve disease resistance require further investigation. Our study found that disease-resistant shrimp exhibited a remarkable ability to prevent Vp_HLVD invasion effectively. To unravel the genetic basis of this resistance, we conducted a transcriptomic analysis with susceptible and disease-resistant shrimp at various time points (0, 6, and 12 h) post-infection with Vp_HLVD. Differential gene expression (DEGs) analysis of uninfected shrimp revealed that disease-resistant individuals displayed higher expression of immune-related genes and pathways compared to their susceptible counterparts. Simultaneously, they exhibited lower expression of Vibrio toxin-binding genes and Vibrio colonization gene, indicating enhanced defense mechanisms in the resistant shrimp. Upon Vp_HLVD infection, DEGs analysis also showed that susceptible shrimp attempt to mount a similar immune response as the disease-resistant shrimp during the early stages of infection. However, as the infection progresses, the defense strategies diverge between the two groups, with the peak of gene response occurring later in the disease-resistant shrimp. Our findings indicated that disease-resistant shrimp did not experience significant stress during the early stages of infection and are capable of effectively enhancing their immune response in the middle and late stages of the infection. In summary, our study enhanced the understanding of the mechanisms employed by disease-resistant shrimp to combat Vibrio, and would help to develop effective strategies for disease prevention and control, ultimately reducing the impact of HLVD on shrimp aquaculture.