A non-occluded, systemic baculovirus that occurs in cells of ectodermal and mesodermal origin and causes high mortality in the black tiger prawn Penaeus monodon

Abstract

for virus isolation and purification, 1 batch of prawns yielded hemolymph fractions dominated by a previously undescribed non-occluded baculovirus rather than YHV. Injection of test shrimp with a semipurified preparation of this virus gave rapid mortality, and examination with the transmission electron microscope revealed a dual infection where cells containing the new virus dominated, but some cells containing YHV could also be seen. The tissues infected by the 2 viruses were similar. However, in contrast to YHV, the new virus was assembled completely in the nucleus and in the absence of occluding protein (polyhedrin). By normal histology, the most characteristic feature of infection was eosinophilic Cowdry A-type inclusions in hypertrophied nuclei with marginated chromatin, especially in epithelial cells of the stomach. These intranuclear inclusions became lightly basophilic in late stages of infection. In the epithelial cells of the gills, ultrastructural pathology included nuclear hypertrophy and cytoplasmic disintegration leading to large voids at lysed cell sites. By negative staining, completely assembled, enveloped virions were ellipsoid to obovate with a distinctive multifibrillar appendage and they measured 276 x 121 nm (excluding the appendage). Enveloped and unenveloped nucleocapsids were significantly different In size, indicating posslble shortening and thickening of the viral core and nucleocapsid during viral assembly. Isolation and punficat~on of the nucleic acid from the new virus yielded double-stranded DNA of approximately 168 lulo base pairs. This DNA did not cross-hybridize with DNA fragments isolated from YHV-infected shrimp or from monodon baculovirus (MBV). The features placed t h~s virus in the family Baculoviridae, subfamily Nudibaculovirinae as PmNOBII, but for convenience we have named it informally as Systemic Ectodermal and Mesodermal Baculovirus (SEMBV).

Molecular epidemiology of white spot syndrome virus within Vietnam

“…Electron microscopic analysis showed that WSSV consists of a rod-shaped nucleocapsid with a cross-hatched appearance, surrounded by a trilaminar envelope with a unique tail-like appendix at one end (Wongteerasupaya et al, 1995;Durand et al, 1997;. The circular dsDNA genome of WSSV has a size of around 300 kb and is one of the largest animal virus genomes that has been entirely sequenced (van Hulten et al, 2001;Yang et al, 2001).…”

Development and application of monoclonal antibodies for the detection of white spot syndrome virus of penaeid shrimp

“…By 1995 WSS virus (WSSV) outbreaks in shrimp culture facilities had been reported in Japan, Korea, Thailand, Taiwan, Indonesia and India affecting farmed populations of P. chinensis, P. monodon, P. japonicus and P. indicus , Winaro 1995, Wongteerasupaya et al 1995, Heo et al 1998, Mohan et al 1998. Partly because of the rapid spread of the virus and its identification by numerous laboratories, the virus has been referred to by various other names including rod-shaped nuclear virus of P. japonicus , systemic ectodermal and mesodermal baculovirus (Wongteerasupaya et al 1995), hypodermal and hematopoietic necrosis baculovirus , white spot baculovirus , Chinese baculovirus (Nadala et al 1997) and P. monodon non-occluded baculovirus . Very rapidly, WSSV spread to other regions of the world.…”

Molecular characterization of a crustin-like antimicrobial peptide in the giant tiger shrimp, Penaeus monodon, and its expression profile in response to various immunostimulants and challenge with WSSV

“…1995). WSSV is an enveloped virus with a large, double-stranded, circular DNA genome (∼300 kb) containing approximately 180 putative open reading frames (ORFs), most of which have no homology with any known genes or proteins in public databases Wongteerasupaya et al 1995;Wang et al 1995;Chang et al 1996;Chen et al 1997;Yang et al 2001). Proper husbandry and management of farms with the application of immunostimulants, probiotics and bioremediators can save the industry from the onslaught of diseases to a certain extent.…”