Premium
Effect of multiple infections with white spot syndrome virus and Vibrio anguillarum on Pacific white shrimp Litopenaeus vannamei (L.): mortality and viral replication
Author(s) -
Jang I K,
Qiao G,
Kim SK
Publication year - 2014
Publication title -
journal of fish diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 85
eISSN - 1365-2761
pISSN - 0140-7775
DOI - 10.1111/jfd.12194
Subject(s) - white spot syndrome , litopenaeus , shrimp , biology , vibrio anguillarum , microbiology and biotechnology , virology , virus , prophenoloxidase , pathogen , innate immune system , vibrio , immune system , immunology , bacteria , fishery , genetics
Abstract Multiple infections are commonly found in practical shrimp culture and may cause more serious consequences than infections by one pathogen only. Therefore, this study was conducted to evaluate the effect of multiple infections with white spot syndrome virus (WSSV) and Vibrio anguillarum on Pacific white shrimp Litopenaeus vannamei (L.), mortality, WSSV replication in vivo and host immune response. In the WSSV single‐infection group (WSSV load, 2 × 10 2 copies μL −1 ), mean cumulative mortality was 29.2%. In the V. anguillarum single‐infection group, cumulative mortality was 12.5% when shrimp were challenged by 10 5 CFU mL −1 of bacteria. In the co‐ and super‐infection groups, 37.5% and 50% cumulative mortalities, respectively, were observed at a lower bacterial concentration of 10 3 CFU mL −1 , suggesting that shrimp with multiple infections died earlier and more frequently than singly infected shrimp. WSSV load after injection was tracked over time by TaqMan quantitative PCR. WSSV load increased more rapidly in the multiple‐infection groups than in the single‐infection group. Additionally, mRNA expression of the genes encoding prophenoloxidase 1 and 2, which are closely involved in innate immunity in shrimp, was down‐regulated more extensively in multiple‐infection groups than in single‐infection groups, as indicated by quantitative reverse‐transcription PCR.