In situ enzyme immunoassays with tissue smears to study horizontal transmission of BMNV in penaeid shrimp and in beach animals

An enzyme immunoassay technique is developed for detecting the baculoviral midgut gland necrosis virus (BMNV) in penaeid shrimp and beach animals. An antiserum was obtained from rabbits immunized with a BMNV purified from Penaeus japnnicus.γ-globulin was isolated and labelled with horseradish peroxidase (HRP).This reagent was used to detect the virus in penaeid shrimp experimentally infected with the BMNV preparalion, in cultured penaeid shrimp and in several beach animals. The technique is specific, simple and sensitive and can be developed into a practical method for the detection of penaeid shrimp viruses. Among 128 tissue samples from 11 beach animals, 77 samples gave positive reactions with the enzyme-labelled immunoglobulin against BMNV from P. japonicas. These animals could possibly constitute a horizontal transmission pathway for cultured penaeid shrimp vcruses.