Molecular detection of viral diseases afecting shrimp farming development*

Abstract

Shrimp farming, as a productive activity, has had an exponential growth in coastal countries from the tropical and subtropical stripe, boosted by the development of several technologies. However, an important challenge still remains in order to achieve a greater yielding certainty: to eradicate the devastating epizootics provoked by viral agents. About 15 viruses are the cause of the worst economical disaster in farms from the Eastern and Western hemispheres. Several traditional diagnostic methods have been employed to detect the presence and assess the prevalence of pathogenic viruses in diverse cultured shrimp species, although their specificity, sensitivity, opportunity, and efficacy are questioned. On the other hand, molecular tools offer opportune detection, and specific diagnostics due to their high sensitivity, and easiness of interpretation. The designing of specific primers, and molecular probes is described. The methods used by the mentioned tools pursuing the detection and diagnose of the presence of viral agents in shrimps selected tissues are also described: amplification of selected genomic fragments by the use of specific primers in the polymerase chain reaction (PCR) or real-time PCR (qPCR), and specific hybridization molecular probes onto solid support (Dot-Blot) or in situ hybridization. Finally, a sanitary control strategy to eradicate the viral origin epizootics is proposed, based on the adequate and systematic application of methods employing molecular tools.