Detection of white spot syndrome virus (WSSV) from hemolymph of Penaeid shrimps Penaeus japonicus by reverse passive latex agglutination assay using high-density latex particles.

A simple reverse passive latex agglutination (RPLA) method for detecting white spot syndrome virus (WSSV) in the hemolymph of infected Kuruma shrimp (Penaeus japonicus) was developed. It was confirmed that WSSV could be detected from the shrimp hemolymph when the latex particles blocked with a casein protein were used as detection reagent. It became clear from the result of the infection trial that viruses are detectable by RPLA before the appearance of overt symptoms of this disease. In addition, an amplification product of 982 bp (s) derived from WSSV by PCR was detected in all the samples in which WSSV was detected by RPLA. This newly developed RPLA assay can examine many samples in a simple manner since hemolymph can be extracted more easily than any other organs. This assay can be used conveniently for virus detection in the culture pond of shrimps or in the field.