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WSSV Infection (wssv + infection)
Selected AbstractsThree tetraspanins from Chinese shrimp, Fenneropenaeus chinensis, may play important roles in WSSV infectionJOURNAL OF FISH DISEASES, Issue 1 2010B Wang Abstract Three members of the tetraspanin/TM4SF superfamily were cloned from Chinese shrimp, Fenneropenaeus chinensis. The deduced amino acid sequences of the three proteins have typical motifs of the tetraspanin/TM4SF superfamily. Phylogenetic analysis of the proteins, together with the known tetraspanins of invertebrates and vertebrates, revealed that they belong to different tetraspanin subfamilies: CD9, CD63 and tetraspanin-3. The three cloned genes of CD9, CD63 and tetraspanin-3 showed apparently different tissue distributions. The CD9 gene (FcCD9) was specifically expressed in the hepatopancreas. While for the CD63 gene (FcCD63), the highest expression was detected in nerves, epidermis and heart, with low expression in haemocytes, ovary, gill, hepatopancreas and stomach and no expression in intestine, muscle and lymphoid organ. Compared with FcCD9 and FcCD63, the tetraspanin-3 gene (FcTetraspanin-3) was more broadly expressed and its highest expression was detected in the intestine. Its expression in nerves was lower than in the intestine, but was higher than in other tissues. Expression in haemocytes, ovary and muscle was much lower than in other tissues. The expression profiles of FcCD9, FcCD63 and FcTetraspanin-3 in different tissues, including haemocytes, lymphoid organ and hepatopancreas, were compared by real-time PCR when shrimp were challenged by live white spot syndrome virus (WSSV) and heat-inactivated WSSV. All three tetraspanins were markedly up-regulated in the live WSSV-challenged shrimp tissues. The data suggested that the three cloned members of TM4SF superfamily in Chinese shrimp may play a key role in the route of WSSV infection. [source] Larvae and early post-larvae of Penaeus monodon (Fabricius) experimentally infected with white spot syndrome virus (WSSV) show no significant mortalityJOURNAL OF FISH DISEASES, Issue 7 2003K Yoganandhan Abstract The pathogenicity of white spot syndrome virus (WSSV) was tested with different developmental stages of Penaeus monodon, i.e. nauplius, protozoeae, mysis, early post-larvae (PL1-10), late post-larvae (PL11-20) and juveniles. WSSV challenge was done by immersion and oral routes. No disease occurred in the larvae and early post-larvae but they were positive for WSSV by nested polymerase chain reaction (PCR) assay. Significant mortality was observed in late post-larvae and juveniles and both single and nested PCR assays gave positive results with these samples. The results demonstrated that WSSV virulence in P. monodon increases with advancing stages of development and that WSSV infection does not result in disease for larvae and post-larvae younger than PL10. [source] Experimental susceptibility of different life-stages of the giant freshwater prawn, Macrobrachium rosenbergii (de Man), to white spot syndrome virus (WSSV)JOURNAL OF FISH DISEASES, Issue 4 2002R B Pramod Kiran Studies were conducted by injecting/feeding white spot syndrome virus (WSSV) derived from infected shrimp, Penaeus monodon (Fabricius), to different life-stages, namely post-larvae, juveniles, sub-adults and adults of Macrobrachium rosenbergii (de Man). The disease was also induced in brood stock, and the eggs and larvae derived from these animals were subsequently tested for WSSV infection. All the stages except egg used for the experiment were found WSSV positive in histopathology, cross infection bioassay and polymerase chain reaction (PCR) analysis. Experimentally infected post-larvae and juveniles showed a high percentage of mortality and an increased rate of cannibalism. The cumulative mortality in post-larvae was up to 28%; with 28,40% cannibalism resulting in a maximum loss of up to 68%. In juveniles, observed mortality and cannibalism were 10,20% and 6.7,30.0%, respectively, and the maximum loss recorded was 50%. In sub-adults, mortality ranged from 2.8 to 6.7%, cannibalism was up to 20% and the total loss was up to 26.7%. Sub-adults and adults were found to be more tolerant to the infection as evidenced by the mortality pattern. A nested (two-step) PCR resulted in a 570-bp product specific to WSSV in all stages, except the eggs. [source] Marine yeast diet confers better protection than its cell wall component (1-3)-,- d -glucan as an immunostimulant in Fenneropenaeus indicusAQUACULTURE RESEARCH, Issue 15 2009Thavarool Puthiyedathu Sajeevan Abstract A comparative study was performed to evaluate the immunostimulatory effect of yeast and yeast-derived glucan in white prawn Fenneropenaeus indicus (sub-adults of ,20 gm). Feed with a whole cell biomass of marine yeast Candida sake S165 (CSY) at a concentration of 10% (w/w) and another feed with 0.2% glucan of C. sake S165 (CSG) were used in the study. Fenneropenaeus indicus were fed with these diets for 40 days and subsequently challenged with the white spot syndrome virus (WSSV). Haematological parameters such as the total haemocyte count, phenoloxidase activity, superoxide anion (O2,) level, haemolymph peroxidase level and post-challenge survival against WSSV infection were determined to assess the immune status. In the present experiment, a higher immunity index and post-challenge survival were recorded in shrimps fed with the whole cell yeast diet. The better immunostimulatory performance of the whole cell yeast diet compared with the glucan diet could be attributed to the cellular constituents of yeast including the cell wall glucan, nucleotides, carotenoid pigments and vitamins. Here we observed that whole cell yeast performed better as an immunostimulant than the extracted cell wall glucans. Therefore, the use of yeast biomass in diets, rather than the yeast cell wall extract, glucan, would confer better protection against microbial infection besides reducing the cost of shrimp production. [source] | ||||||||||