scholarly journals Circulating Phylotypes of White Spot Syndrome Virus in Bangladesh and Their Virulence

2022 ◽  
Vol 10 (1) ◽  
pp. 191
Author(s):  
Mehedi Mahmudul Hasan ◽  
M. Nazmul Hoque ◽  
Firoz Ahmed ◽  
Md. Inja-Mamun Haque ◽  
Munawar Sultana ◽  
...  

White Spot Syndrome Virus (WSSV) has emerged as one of the most prevalent and lethal viruses globally and infects both shrimps and crabs in the aquatic environment. This study aimed to investigate the occurrence of WSSV in different ghers of Bangladesh and the virulence of the circulating phylotypes. We collected 360 shrimp (Penaeus monodon) and 120 crab (Scylla sp.) samples from the south-east (Cox’s Bazar) and south-west (Satkhira) coastal regions of Bangladesh. The VP28 gene-specific PCR assays and sequencing revealed statistically significant (p < 0.05, Kruskal–Wallis test) differences in the prevalence of WSSV in shrimps and crabs between the study areas (Cox’s Bazar and Satkhira) and over the study periods (2017–2019). The mean Log load of WSSV varied from 8.40 (Cox’s Bazar) to 10.48 (Satkhira) per gram of tissue. The mean values for salinity, dissolved oxygen, temperature and pH were 14.71 ± 0.76 ppt, 3.7 ± 0.1 ppm, 34.11 ± 0.38 °C and 8.23 ± 0.38, respectively, in the WSSV-positive ghers. The VP28 gene-based phylogenetic analysis showed an amino-acid substitution (E→G) at the 167th position in the isolates from Cox’s Bazar (referred to as phylotype BD2) compared to the globally circulating one (BD1). Shrimp PL artificially challenged with BD1 and BD2 phylotypes with filtrates of tissue containing 0.423 × 109 copies of WSSV per mL resulted in a median LT50 value of 73 h and 75 h, respectively. The in vivo trial showed higher mean Log WSSV copies (6.47 ± 2.07 per mg tissue) in BD1-challenged shrimp PL compared to BD2 (4.75 ± 0.35 per mg tissue). Crabs infected with BD1 and BD2 showed 100% mortality within 48 h and 62 h of challenge, respectively, with mean Log WSSV copies of 12.06 ± 0.48 and 9.95 ± 0.37 per gram tissue, respectively. Moreover, shrimp antimicrobial peptides (AMPs), penaeidin and lysozyme expression were lower in the BD1-challenged group compared to BD2 challenged shrimps. These results collectively demonstrated that relative virulence properties of WSSV based on mortality rate, viral load and expression of host immune genes in artificially infected shrimp PL could be affected by single aa substitution in VP28.

Author(s):  
Mehedi Mahmudul Hasan ◽  
M. Nazmul Hoque ◽  
Firoz Ahmed ◽  
Md. Inja-Mamun Haque ◽  
Munawar Sultana ◽  
...  

White Spot Syndrome Virus (WSSV) has emerged as one of the most prevalent and lethal viruses globally, and infects both shrimps and crabs in the aquatic environment. This study aimed to investigate the occurrence of WSSV in different ghers of Bangladesh and the virulence of the circulating phylotypes. We collected 360 shrimp (Penaeus monodon) and 120 crab (Scylla sp.) samples from the South-East (Cox&rsquo;s Bazar) and South-West (Satkhira) coastal regions of Bangladesh. The VP28 gene-specific PCR assays and sequencing revealed statistically significant (p &lt; 0.05, Kruskal Wallis test) differences in the prevalence of WSSV in shrimps and crabs between the study areas (Cox&rsquo;s Bazar and Satkhira), and over the study periods (2017-2019). The mean Log load of WSSV varied from 8.40 (Cox&rsquo;s Bazar) to 10.48 (Satkhira) per gram of tissue. The mean values for salinity, dissolved oxygen, temperature and pH were 14.71&plusmn;0.76 ppt, 3.7&plusmn;0.1 ppm, 34.11&plusmn;0.38˚C and 8.23&plusmn;0.38, respectively in the WSSV-positive ghers. The VP28 gene-based phylogenetic analysis showed an amino-acid substitution (E&rarr;G) at 167th position in the isolates from Cox&rsquo;s Bazar (referred to as phylotype BD2) compared to the globally circulating one (BD1). Shrimp PL artificially challenged with BD1 and BD2 phylotypes with filtrates of tissue containing 0.423 X 109 copies of WSSV per mL resulted a median LT50 value of 73 hrs and 75 hrs, respectively. The in-vivo trial showed higher mean Log WSSV copies (6.47&plusmn;2.07 per mg tissue) in BD1 challenged shrimp PL compared to BD2 (4.75&plusmn;0.35 per mg tissue). Crabs infected with BD1 and BD2 showed 100% mortality within 48 hrs and 62 hrs of challenge, respectively with mean Log WSSV copies of 12.06&plusmn;0.48 and 9.95&plusmn;0.37 per gram tissue, respectively. Moreover, shrimp antimicrobial peptides (AMPs) penaeidin and lysozyme expression was lower in BD1 challenged group compared to BD2 challenged shrimps. These results collectively demonstrated that relative virulence properties of WSSV based on mortality rate, viral load and expression of host immune genes in artificially infected shrimp PL could be affected by single aa substitution in VP28.


2011 ◽  
Vol 30 (4-5) ◽  
pp. 1007-1013 ◽  
Author(s):  
Rajreddy Patil ◽  
K.M. Shankar ◽  
S.R. Krupesha Sharma ◽  
Amod Kulkarni ◽  
Prakash Patil ◽  
...  

2005 ◽  
Vol 86 (7) ◽  
pp. 2081-2100 ◽  
Author(s):  
Hendrik Marks ◽  
Oscar Vorst ◽  
Adèle M. M. L. van Houwelingen ◽  
Mariëlle C. W. van Hulten ◽  
Just M. Vlak

White spot syndrome virus, type species of the genus Whispovirus in the family Nimaviridae, is a large, double-stranded DNA (dsDNA) virus that infects crustaceans. The genome of the completely sequenced isolate WSSV-TH encodes 184 putative open reading frames (ORFs), the functions of which are largely unknown. To study the transcription of these ORFs, a DNA microarray was constructed, containing probes corresponding to nearly all putative WSSV-TH ORFs. Transcripts of 79 % of these ORFs could be detected in the gills of WSSV-infected shrimp (Penaeus monodon). Clustering of the transcription profiles of the individual genes during infection showed two major classes of genes: the first class reached maximal expression at 20 h post-infection (p.i.) (putative early) and the other class at 2 days p.i. (putative late). Nearly all major and minor structural virion-protein genes clustered in the latter group. These data provide evidence that, similar to other large, dsDNA viruses, the WSSV genes at large are expressed in a coordinated and cascaded fashion. Furthermore, the transcriptomes of the WSSV isolates WSSV-TH and TH-96-II, which have differential virulence, were compared at 2 days p.i. The TH-96-II genome encodes 10 ORFs that are not present in WSSV-TH, of which at least seven were expressed in P. monodon as well as in crayfish (Astacus leptodactylus), suggesting a functional but not essential role for these genes during infection. Expression levels of most other ORFs shared by both isolates were similar. Evaluation of transcription profiles by using a genome-wide approach provides a better understanding of WSSV transcription regulation and a new tool to study WSSV gene function.


2009 ◽  
Vol 90 (6) ◽  
pp. 1491-1498 ◽  
Author(s):  
Sirinit Tharntada ◽  
Sirikwan Ponprateep ◽  
Kunlaya Somboonwiwat ◽  
Haipeng Liu ◽  
Irene Söderhäll ◽  
...  

The anti-lipopolysaccharide factor (ALF) from the black tiger shrimp, Penaeus monodon, has been shown previously to exhibit a broad spectrum of activity against various strains of bacteria and fungi. Herein, the recombinant ALFPm3 (rALFPm3) protein was examined for its role in the defence against white spot syndrome virus (WSSV) infection in haematopoietic (Hpt) cell cultures of the freshwater crayfish, Pacifastacus leniusculus, as well as in live P. monodon shrimps. Incubation of Hpt cell cultures with a mixture of WSSV and rALFPm3 resulted in a dose-dependent decrease in VP28 gene expression levels, compared with those incubated with WSSV alone, with an rALFPm3 IC50 value lower than 2.5 μM. However, pre-treatment of Hpt cells with 5 μM rALFPm3 showed no induced protection against subsequent WSSV infection, whereas the synthetic crayfish ALF peptide could protect cells at a higher concentration (10 μM). The in vivo role of ALFPm3 was examined by injection of P. monodon with WSSV pre-treated with rALFPm3 protein. The results clearly showed that rALFPm3 was able to reduce WSSV propagation and prolong the survival of shrimps.


Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1378
Author(s):  
Kandasamy Saravanan ◽  
Jayasimhan Praveenraj ◽  
Rajendran Kiruba-Sankar ◽  
Varsha Devi ◽  
Utpal Biswas ◽  
...  

The present study was intended to screen the wild crustaceans for co-infection with Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) and White Spot Syndrome Virus (WSSV) in Andaman and Nicobar Archipelago, India. We screened a total of 607 shrimp and 110 crab samples using a specific polymerase chain reaction, and out of them, 82 shrimps (13.5%) and 5 (4.5%) crabs were found positive for co-infection of IHHNV and WSSV. A higher rate of co-infection was observed in Penaeus monodon and Scylla serrata than other shrimp and crab species. The nucleotide sequences of IHHNV and WSSV obtained from crab in this present study exhibited very high sequence identity with their counterparts retrieved from various countries. Histopathological analysis of the infected shrimp gill sections further confirmed the eosinophilic intra-nuclear cowdry type A inclusion bodies and basophilic intra-nuclear inclusion bodies characteristics of IHHNV and WSSV infections, respectively. The present study serves as the first report on co-infection of WSSV and IHHNV in Andaman and Nicobar Archipelago, India and accentuates the critical need for continuous monitoring of wild crustaceans and appropriate biosecurity measures for brackishwater aquaculture.


2017 ◽  
Vol 10 (1) ◽  
pp. 55
Author(s):  
Ketut Mahardika ◽  
Zafran Zafran ◽  
Lsti Koesharyani

White spot syndrome (WSS) telah ditemukan pada banyak spesies udang dan kepiting, tidak saja di Asia tetapi hampir di seluruh dunia.


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