RESUMO
White spot syndrome virus (WSSV) is a major pathogen affecting the shrimp industry worldwide. In a preliminary study, WSSV binding protein (WBP) was specifically bound to the VP26 protein of WSSV. Therefore, we have developed the label-free affinity immunosensor using the WBP together with anti-GST-VP26 for quantitative detection of WSSV in shrimp pond water. When the biological molecules were immobilized on a gold electrode to form a self-assembled monolayer, it was then used to detect WSSV using a flow injection system with optimized conditions. Binding between the different copies of WSSV and the immobilized biological molecules was detected by an impedance change (ΔZâ³) in real time. The sensitivity of the developed immunosensor was in the linear range of 1.6 × 10(1)-1.6 × 10(6) copies/µl. The system was highly sensitive for the analysis of WSSV as shown by the lack of impedance change when using yellow head virus (YHV). The developed immunosensor could be reused up to 37 times (relative standard deviation (RSD), 3.24 %) with a good reproducibility of residual activity (80-110 %). The immunosensor was simple to operate, reliable, reproducible, and could be applied for the detection and quantification of WSSV in water during shrimp cultivation.
Assuntos
Aquicultura , Técnicas Biossensoriais/métodos , Decápodes/crescimento & desenvolvimento , Decápodes/virologia , Imunoensaio/métodos , Água , Vírus da Síndrome da Mancha Branca 1/isolamento & purificação , Animais , Limite de Detecção , Reação em Cadeia da Polimerase , Proteínas Recombinantes/metabolismo , Reprodutibilidade dos Testes , Vírus da Síndrome da Mancha Branca 1/genéticaRESUMO
White spot syndrome virus (WSSV) is a major cause of infectious disease in cultured shrimp. A fast and reliable method for detecting and monitoring the amount of WSSV during farming would be extremely useful. This work describes a sandwich immunoassay that uses anti-GST-VP26, a WSSV-binding protein (WBP), and modified streptavidin magnesphere paramagnetic particles (SMPPs) to develop the technique. The WBP was immobilized on SMPPs and later bound to different copies of WSSV. The binding was detected using anti-GST-VP26 conjugated to alkaline phosphatase. This enzymatic reaction successfully changed the test solution to a concentration-dependent yellow color that was measured at 405 nm. The sensitivity of this method was between 1.6 × 10(4) and 1.6 × 10(7) copies µL(-1) of WSSV. In this study, the color for detection and semiquantitative analysis is easily observed and measured and can lead to the development of a test kit for screening WSSV during shrimp farming.
