scholarly journals Genetic variations among white spot syndrome virus (WSSV) isolates from shrimp farms in Gujarat, north-west coast of India

2017 ◽  
Vol 64 (4) ◽  
Author(s):  
Prasanna Kumar Patil ◽  
Haresh G. Solanki ◽  
Subhendu Kumar Otta ◽  
Krishna Patel ◽  
P. Saravanan ◽  
...  
Keyword(s):  
West Coast ◽  
White Spot Syndrome Virus ◽  
Variable Number Tandem Repeat ◽  
Repeat Sequence ◽  
White Spot ◽  
Virus Genotype ◽  
North West ◽  
West Coast Of India ◽  
White Spot Syndrome ◽  
Shrimp Farms

The present paper documents the molecular diagnosis and genotyping of white spot syndrome virus (WSSV) isolates collected from different shrimp farms of Gujarat, north-west coast of India. Preliminary diagnosis was done using singletube PCR and genotyping of isolates by analysis of variable number tandem repeat sequence (VNTRS) in minisatellites viz., ORF 94, ORF 125, ORF 75 and ORF 75 flank. Out of the 79 samples analysed, 32 (33.80%) were positive with low (54.17%), medium (8.33%) and high (37.50%) severity of infection. Genotyping, using ORF 94 revealed that repeat units (RUs) 4 and 11 were the most frequent ones (32%) while ORF 125 showed 5 different repeat types of which RU 5 was the most common (45.83%). Two genotypes were observed for ORF 75, one showed multiple repeats of two 45 bp, followed by a 57 bp, whereas the other showed two repeats that included 5 and 4 repeats of 45 bp. Sequence analysis of the 54 bp variable sequence of ORF 94 RU type 4 revealed single-nucleotide polymorphism (SNP) at 47th base. Based on the results from ORF94, dominance of RU types 11or 4 were recorded for the first time in India and one sample showed 2 bands of different sizes indicating the prevalence of two different genotypes infecting the same pond at a given time. Further, no correlation could be observed between the virus genotype and the severity of the mortality in the outbreaks. The results suggest the widespread occurrence of WSSV in the region and circulation of distinct virus genotypes.

scholarly journals White spot syndrome virus and Enterocytozoon hepatopenaei in shrimp farms in Costa Rica

2020 ◽  
pp. 479-489
Author(s):  
Nelson Peña Navarro ◽  
Ruth Castro Vásquez ◽  
Gaby Dolz
Keyword(s):  
Costa Rica ◽  
White Spot Syndrome Virus ◽  
Low Frequency ◽  
Small Subunit ◽  
White Spot ◽  
Production Cycle ◽  
Central Pacific ◽  
White Spot Syndrome ◽  
Enterocytozoon Hepatopenaei ◽  
Shrimp Farms

Introduction. The white spot syndrome virus (WSSV) causes systemic destruction of ectodermal and mesodermal tissues in shrimp and can cause 100 % mortality. Enterocytozoon hepatopenaei (EHP) is an intracellular microsporidian that causes lysis of epithelial cells in hepatopancreatic tubules in shrimp. Objective. Detect the presence of WSSV and EHP in fifteen shrimp farms in the Gulf of Nicoya and the Central Pacific from Costa Rica. Materials and methods. Between January 2017 and July 2018 water during the filling process of the pond, postlarvae, and juvenile shrimp of Penaeus vannamei was collected, during a production cycle in each one of the fifteen farms. Samples were analyzed through polymerase chain reaction (PCR) using primers and protocols to detect the VP41B gene in WSSV, and the small subunit ribosomal RNA gene of EHP. Results. The presence of WSSV was detected in one farm, while EHP was not detected in any of the fifteen farms. The sequencing of the amplified segments of the VP41B gene showed 100 % identity with isolated shrimp sequences in Taiwan and Mexico. Conclusion. WSSV was detected at a very low frequency and EHP was not detected in this study. It is necessary to continue monitoring these agents in the country’s shrimp farms.

scholarly journals Genotyping of white spot syndrome virus prevalent in shrimp farms of India

2008 ◽  
Vol 78 ◽  
pp. 189-198 ◽  
Author(s):  
B Pradeep ◽  
M Shekar ◽  
N Gudkovs ◽  
I Karunasagar ◽  
I Karunasagar
Keyword(s):  
White Spot Syndrome Virus ◽  
White Spot ◽  
White Spot Syndrome ◽  
Shrimp Farms

scholarly journals Genotype Diversity and Spread of White Spot Syndrome Virus (WSSV) in Madagascar (2012–2016)

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1713
Author(s):  
Alain Moïse Onihary ◽  
Iony Manitra Razanajatovo ◽  
Lydia Rabetafika ◽  
Alexandra Bastaraud ◽  
Jean-Michel Heraud ◽  
...  
Keyword(s):  
White Spot Syndrome Virus ◽  
Penaeus Monodon ◽  
Macrobrachium Rosenbergii ◽  
Culture Industry ◽  
White Spot ◽  
Type I ◽  
Shrimp Culture ◽  
White Spot Disease ◽  
North West ◽  
White Spot Syndrome

White Spot Disease (WSD) caused by the White Spot Syndrome Virus (WSSV) is the most devastating viral disease threatening the shrimp culture industry worldwide, including Madagascar. WDS was first reported on the island in 2012; however, little is known about the circulation of the virus and its genetic diversity. Our study aimed at describing the molecular diversity and the spread of WSSV in the populations of Madagascan crustaceans. Farmed and wild shrimps were collected from various locations in Madagascar from 2012 to 2016 and were tested for WSSV. Amplicons from positive specimens targeting five molecular markers (ORF75, ORF94, ORF125, VR14/15 and VR23/24) were sequenced for genotyping characterizations. Four genotypes were found in Madagascar. The type-I genotype was observed in the south-west of Madagascar in April 2012, causing a disastrous epidemic, then spread to the North-West coast. Type-II strains were detected in October 2012 causing an outbreak in another Penaeus monodon farm. In 2014 and 2015, types II and III were observed in shrimp farms. Finally, in 2016, types II and IV were found in wild species including Fenneropenaeus indicus, Metapenaeus monoceros, Marsupenaeus japonicus and Macrobrachium rosenbergii. Considering the economic importance of the shrimp industry for Madagascar, our study highlights the need to maintain WSSV surveillance to quickly take appropriate countermeasures in case of outbreak and to sustain this industry.

scholarly journals Analysis of repeated compound units in ORF94 of white spot syndrome virus isolated from Litopenaeus vannamei from outbreak and non outbreak shrimp farms in Sonora, Mexico

2016 ◽  
Vol 44 (4) ◽  
pp. 850-854 ◽  
Author(s):  
Libia Rodriguez Anay ◽  
Libia Rodriguez Anay ◽  
Jose Ibarra Gamez ◽  
Fernando Lares Villa ◽  
Ramon Casillas Hernandez ◽  
...  
Keyword(s):  
Litopenaeus Vannamei ◽  
White Spot Syndrome Virus ◽  
White Spot ◽  
White Spot Syndrome ◽  
Shrimp Farms

The incidence of suspected white spot syndrome virus in semi-intensive and extensive shrimp farms in Bangladesh: implications for management

2011 ◽  
Vol 43 (9) ◽  
pp. 1357-1371 ◽  
Author(s):  
Manjurul Karim ◽  
Rayhan Hayat Sarwer ◽  
Alan C. Brooks ◽  
Rick Gregory ◽  
Murshed E. Jahan ◽  
...  
Keyword(s):  
White Spot Syndrome Virus ◽  
White Spot ◽  
White Spot Syndrome ◽  
Shrimp Farms

A new strain of white spot syndrome virus affecting Litopenaeus vannamei in Indian shrimp farms

2018 ◽  
Vol 41 (7) ◽  
pp. 1129-1146 ◽  
Author(s):  
S Sivakumar ◽  
S Vimal ◽  
S Abdul Majeed ◽  
S Santhosh Kumar ◽  
G Taju ◽  
...  
Keyword(s):  
Litopenaeus Vannamei ◽  
White Spot Syndrome Virus ◽  
White Spot ◽  
White Spot Syndrome ◽  
Shrimp Farms
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