Impact of Vibrio parahaemolyticus and white spot syndrome virus (WSSV) co-infection on survival of penaeid shrimp Litopenaeus vannamei

摘要: White spot syndrome virus (WSSV) is an important viral pathogen that infects farmed penaeid shrimp, and the threat of Vibrio parahaemolyticus infection to shrimp farming has become increasingly severe. Viral bacterial cross or superimposed infections may induce higher mortality. We used a feeding method infect Litopenaeus vannamei with WSSV then injected low dose V. (WSSV+Vp), we first infected L. low-dose injection fed achieve (Vp+WSSV). The eff ect co-infection on survival was evaluated by comparing cumulative mortality rates between experimental control groups. also spread hemolymph thiosulfate citrate bile salt sucrose agar plates determine number Vibrio, copy in gills determined using absolute quantitative polymerase chain reaction (PCR) method. LvMyD88 Lvakt gene expression levels were detected real-time PCR cause diff erent rates. Our results show (1) rate WSSV+Vp group reached 100% day 10 after infection, whereas Vp+WSSV WSSV-alone approached days 11 13 infection; (2) alone declined gradually, other groups showed significant increases numbers (P<0.05); (3) WSSV+Vp, Vp+WSSV, increased from 105 107 /mg tissue 72, 96, 144 h respectively. These suggest accelerated proliferation vice versa. combined both led massive death vannamei.