Studies on the pathogenicity of systemic ectodermal and mesodermal baculovirus and its detection in shrimp by immunological methods

• Published in: Aquaculture 1998-01, Vol.160 (1), p.31-45
• Main Authors: Sahul Hameed, A.S, Anilkumar, M, Stephen Raj, M.L, Jayaraman, Kunthala
• Format: Article
• Language: English
• Subjects: Animal aquaculture; Animal productions; BACULOVIRIDAE; Biological and medical sciences; Crustacea; DIAGNOSIS; DIAGNOSTIC; DIAGNOSTICO; Freshwater; Fundamental and applied biological sciences. Psychology; IMMUNOLOGICAL TECHNIQUES; Immunology; Invertebrate aquaculture; Nitrocellulose-enzyme immunoblot method; PATHOGENICITY; Pathology; PATOGENICIDAD; PENAEUS INDICUS; PENAEUS MONODON; POUVOIR PATHOGENE; Seafood; Shellfish; Shrimp—diseases; Systemic ectodermal and mesodermal baculovirus; TECHNIQUE IMMUNOLOGIQUE; TECNICAS INMUNOLOGICAS; Viruses
• ISSN: 0044-8486; 1873-5622
• DOI: 10.1016/S0044-8486(97)00221-4

The purpose of this study was to isolate and purify the systemic ectodermal and mesodermal baculovirus (SEMBV) and develop diagnostic methods to detect SEMBV in shrimp. The SEMBV- infected shrimp were obtained from different farms located near Nellore, India. The clinical signs of infected shrimp were lethargy, anorexia, expansion of chromatophores and white spots. Using 10–50% sucrose density gradients, SEMBV was purified. The intact virus particles were enveloped, elliptical and measured 266±13 nm in length and 112±7 nm in width. The nucleocapsids released on Triton ×100 disruption were cylindrical and measured 420±18 nm in length and 68±5 nm in width. This virus was proved to be pathogenic to Penaeus indicus and Penaeus monodon by intramuscular injection (i.m.) and by the oral route. The presence of SEMBV in hemolymph, eyestalk, gills, head soft tissue, abdominal muscle and hepatopancreas of infected P. monodon was examined by bioassay and nitrocellulose-enzyme immunoblot (NC-EIB) methods. The results showed its presence in all the organs and tissues except in hepatopancreas. Three structural proteins with molecular weights of 27, 22 and 18 kDa were identified from the purified preparation of SEMBV by SDS–PAGE. The antiserum raised against prominent viral protein (27 kDa) in mice was used to detect SEMBV in shrimp by NC-EIB and competitive ELISA techniques. A simple diagnostic method to detect SEMBV in shrimp without sacrificing the animal is described.