Lymphoid organ virus of Penaeus monodon from Australia

Abstract

Subadult Penaeus monodon shrimp were sampled from 4 farms in Queensland, Australia. Histological observations on lymphoid organs showed the formation of abnormal cell foci, which resembled tubules lacking a central hemolymph vessel. These formations contained hypertrophied nuclei with marginated chromatin, vacuolated cells and inclusion bodies which stained positive with Feulgen's reaction. Male and female F! monodon broodstock were sampled from 1 farm and showed the same abnormal histological features within the lymphoid organ as the subadults. Electron microscopy revealed tightly enveloped, cylindrical particles, 163-200 nm X 36-63 nm, packed into paracrystalline arrays within the cytoplasm and infrequently within the nucleus. Arrays of virions were also observed within the cytoplasm of broodstock gill cells. Cross-sections of the particles revealed electron dense nucleic acid cores and envelopes. Nucleocapsids, 83-590 nm X 13-15 nm, were seen free and in vesicles within the cytoplasm. A negatively stained preparation of partially purified lymphoid organ revealed a nucleocapsid with one conical end. Lymphoid organ virus (LOV) resembles yellow-head virus (YHV) from Thailand in its morphology and cytopathology and rhabdovirus of penaeid shrimp (RPS) from the Americas in its cytopathology.

A yellow head virus gene probe:nucleotide sequence and application for in situ hybridization

“…Other YHV-like viruses, such as gill associated virus (GAV) and lymphoid organ virus (LOV), have been reported from penaeid shrimp cultured in Australia (Spann et al 1995(Spann et al , 1997. The proposed relationship between the Australian YHV-like viruses and YHV was based on histological changes in the infected shrimp and characteristics of the virions by electron microscopy.…”

Differences in the susceptibility of some penaeid prawn species to gill-associated virus (GAV) infection

“…LOV) infection. Lymphoid organs displayed normal tubule structure and contained spheroids of hypertrophic, infected cells (Spann et al 1995). By light microscopy, there was no evidence of spheroid formation in P. esculentus, Marsupenaeus japonicus or Fenneropenaeus merguiensis used in these experiments.…”

“…Lymphoid organ virus (LOV) has also been described as a rod-shaped, enveloped RNA virus that is endemic in healthy wild and cultured Penaeus monodon in Queensland (Spann et al 1995). Screening of broodstock collected in northern Queensland has indicated a prevalence of LOV infection that exceeds 96% (Cowley et al 2000b).…”

PENGARUH PERBEDAAN WAKTU APLIKASI PROBIOTIK TERHADAP KUALITAS AIR DAN SINTASAN PASCA LARVA UDANG WINDU (Penaeus monodon)

“…Kasus penyakit pada budidaya udang beberapa tahun terakhir ini, melanda Indonesi a dan n egara-n egara l ain sep ert i Thailand (Pasharawipas et al, 1998;Ruangpan et al, 1998;Sukhumsirichart et al, 1998), Taiwan (Peng et al, 2001), Filipina (Albaladejo et al, 1998;Loh et al, 1998), India , Australia (Spann et al, 1995), Jepang (Kono et al, 2004), dan Amerika (Dhar et al, 2001), kini sedikit demi sedikit mulai dapat teratasi. Hal ini bukan karena penyakit virus sebagai penyebab utamanya yang dapat diatasi, akan tetapi terutama karena subtitusi dari udang windu ke vaname, meskipun pada kenyataannya bahwa udang vaname juga tidak terlepas dari serangan penyakit terutama WSSV (Rodriguez et al, 2003;SanchezMartinez et al, 2007).…”