White spot syndrome virus (WSSV) and prevalence of disease resistance in a commercially cultured population of Penaeus monodon Fabricius, 1798 (Decapoda, Dendrobranchiata)

Abstract

White spot disease (WSD) caused by the white spot syndrome virus (WSSV) is the leading cause for huge economic destruction in the shrimp aquaculture industry. The present study investigates the prevalence of WSSV and disease-resistant shrimps among a commercially cultured population of Penaeus monodon Fabricius, 1798. Results suggest that WSSV prevalence among 32 culture ponds affected by various diseases was 58.2% cumulatively in 2009 and 2010. Real-time PCR yielded 1.46 x 108, 1.94 x 106 and 3.6 x 104 copies of WSSV per fig of genomic DNA of shrimp in severe, moderate and low infected shrimps, successively. Among the shrimps collected, the prevalence of disease resistance was 31.4% and 37.1% consecutively in 2009 and 2010. It was found that 34% of the shrimps were disease resistant while considering both years. This study shows the importance of using disease-resistant seeds for better shrimp health management. RÉSUMÉLa maladie des points blancs (WSD) causée par le virus du syndrome des points blancs (WSSV) est la principale cause d'importantes pertes économiques dans l'industrie aquacole des crevettes. Cette étude examine la prévalence de WSSV et les crevettes résitantes à la maladie dans les populations d'aquaculture de Penaeus monodon Fabricius, 1798. Les résultats suggèrent que la prévalance de WSSV parmi les 32 bassins de culture affectés par des maladies variées a été pour 2009 et 2010 en moyenne de 58,2%. Le montant de WSSV mesuré par PCR en temps réel a été chez les crevettes infectées sévèrement, moyennement ou peu, successivement de 1,46 x 108, 1,94 x 106 et 3,6 x 104 copies de WSSV fig~1 de DNA génomique de crevette. Parmi les crevettes collectées, la prévalence de la résistance à la maladie a été de 31,4% en 2009 et 37,1% en 2010. Il a été trouvé que 34% des crevettes étaient résistantes en considérant les deux années. Cette étude souligne l'importance d'utiliser des souches résistant à la maladie pour une meilleure gestion de la santé des crevettes.

Circulatory white spot syndrome virus in South-West region of Bangladesh from 2014 to 2017: molecular characterization and genetic variation

“…In Bangladesh, it has been observed from field experience that some farmers in South-West region are able to obtain a reasonably good harvest despite the presence of WSSV infection characterized by severe white spot on carapace, while similar observations have also been reported from China (Lan et al 2002 ). These observations suggested the existence of possible disease resistant shrimp and genetic variants of WSSV (Chakrabarty et al 2014a , b ; Mallik et al 2016 ; Morse 1994 ). Genetic variants arisen due to mutations could be a probable reason behind molecular diagnostic failure mainly owing to inhibition of binding PCR primers; that might lead to false negative PCR results or non-specific PCR products which in return, limits the use of PCR based diagnostic kits (Mendoza-cano and Sanchez-paz 2013 ; Kwok et al 1990 ).…”