17 research outputs found
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Development and Characterization of Monoclonal Antibodies against the Snakehead Rhabdovirus
Monoclonal antibodies (MAbs) directed against the snakehead rhabdovirus (SHRV) were produced. These MAbs were characterized by immunofluorescence and neutralization tests, and by their ability to immunoprecipitate viral proteins. Of 15 MAbs developed, 9 were isotyped as IgG1 and 6 were IgG2a. Eight of the MAbs recognized the viral glycoprotein in an immuneprecipitation assay. Three of these, designated E1-9A, P10C, and O10F, had neutralizing activity. By immunofluorescence, 12 MAbs showed good binding activity in SHRV-infected epithelioma papulosum cyprini cells. In an indirect fluorescence assay, the MAbs gave varied staining patterns depending upon the viral structural proteins recognized.Keywords: Structural proteins, Snakehead rhabdovirus, Immunofluorescence, Monoclonal antibodie
A novel 'skinny pot-belly' disease in Asian seabass fry, Lates calcarifer (Bloch)
In Singapore, viral nervous necrosis (VNN) is
considered to be the most serious disease of farmed
Asian seabass fry, Lates calcarifer (Bloch) (barramundi), causing mortalities of 80–100% and heavy
economic loss (Lim, Chong & Kueh 1997; Kasornchandra 2002). When some ‘skinny pot-bellied’
seabass fry were presented to the Aquatic Animal
Health Laboratory early in 2004, with a history that
the disease was usually first observed at around
3 weeks of age, VNN was the prime suspect. Instead
of central nervous lesions, however (Munday,
Langdon, Hyatt & Humphrey 1992), histopathological examination showed the presence of a severe
necrotizing and ulcerative enteritis, progressing to
perforation and peritonitis, with disseminated
multifocal granulomas. Associated with these lesions
were numerous bacterial colonies. This preliminary
report presents a description of this novel systemic
bacterial disease of young seabass, typified by
emaciation and abdominal distension, and associated with high mortality. Immunohistochemistry
suggests an association with Edwardsiella ictaluri
Comparison of rhabdoviruses associated with epizootic ulcerative syndrome (EUS) with respect to their structural proteins, cytopathology and serology
The Development and Characterization of a Cell Culture System from Indian Mud Crabs Scylla serrata
Research papers on the causes, effects, treatments, and prevention of diseases of marine and freshwater organisms, particularly fish and shellfishCommercially available culture media and supplements were tested for their potential to produce primary cell cultures from tissues of Indian mud crabs Scylla serrata. Eight commercially available culture media from Sigma-Aldrich (Leibovitz's L-15, Medium 199, Grace's Insect Medium, Minimal Essential Medium, Dulbecco's Modified Eagle Medium, TC-100 Insect Medium, IPL-41 Insect Medium, and Roswell Park Memorial Institute) were examined. Three different supplements (amino acid and sugar [AS], crab muscle extract [CME], and natural seawater [NSW]) were also examined. The hemocyte culture appeared to grow well for a maximum period of 21 d in 2 × L-15 medium supplemented with AS and 15% fetal bovine serum (FBS). Partial amplification and sequencing of the cytochrome oxidase subunit I (COI) gene confirmed that the primary hemocytes originated from Indian mud crabs. The effects of four metals on hemocyte viability were evaluated using the MTT assay. Of the four metals examined (arsenic, lead, cobalt, and nickel), cobalt and nickel were more toxic to the crab cells than the other metals. Both acridine orange/ethidium bromide and Hoechst staining showed the presence of apoptosis and necrosis in metal-treated groups, which suggests that metals in an aquatic environment induce death of the Indian mud crab's hemocytes. The hemocyte primary cell culture was also used to study the cytotoxicity effect of bacterial extracellular products from Vibrio harveyi and white spot syndrome virus. This study demonstrates that hemocyte primary cell culture can be used as a tool to study viral and bacterial pathogenesis and to assess the cytotoxicity of pollutants present in aquatic environments.Not Availabl
Response of crayfish, Procambarus clarkii, haemocytes infected by white spot syndrome virus
White spot syndrome virus ( WSSV) is a serious pathogen of aquatic crustaceans. Little is known about its transmission in vivo and the immune reaction of its hosts. In this study, the circulating haemocytes of crayfish, Procambarus clarkii, infected by WSSV, and primary haemocyte cultures inoculated with WSSV, were collected and observed by transmission electron microscopy and light microscopy following in situ hybridization. In ultrathin sections of infected haemocytes, the enveloped virions were seen to be phagocytosed in the cytoplasm and no viral particles were observed in the nuclei. In situ hybridization with WSSV-specific probes also demonstrated that there were no specific positive signals present in the haemocytes. Conversely, strong specific positive signals showed that WSSV replicated in the nuclei of gill cells. As a control, the lymphoid organ of shrimp, Penaeus monodon, infected by WSSV was examined by in situ hybridization which showed that WSSV did not replicate within the tubules of the lymphoid organ. In contrast to previous studies, it is concluded that neither shrimp nor crayfish haemocytes support WSSV replication.White spot syndrome virus (WSSV) is a serious pathogen of aquatic crustaceans. Little is known about its transmission in vivo and the immune reaction of its hosts. In this study, the circulating haemocytes of crayfish, Procambarus clarkii, infected by WSSV, and primary haemocyte cultures inoculated with WSSV, were collected and observed by transmission electron microscopy and light microscopy following in situ hybridization. In ultra-thin sections of infected haemocytes, the enveloped virions were seen to be phagocytosed in the cytoplasm and no viral particles were observed in the nuclei. In situ hybridization with WSSV-specific probes also demonstrated that there were no specific positive signals present in the haemocytes. Conversely, strong specific positive signals showed that WSSV replicated in the nuclei of gill cells. As a control, the lymphoid organ of shrimp, Penaeus monodon, infected by WSSV was examined by in situ hybridization which showed that WSSV did not replicate within the tubules of the lymphoid organ. In contrast to previous studies, it is concluded that neither shrimp nor crayfish haemocytes support WSSV replication