Analysis of white spot syndrome virus (WSSV) consignment in the progeny of <span style="mso-bidi-font-weight:bold">specific pathogen free (SPF) Pacific <i>Litopenaeus vannamei </i>by RT-PCR using SYBR Green chemistry<i><span style="mso-bidi-font-weight:bold"></span></i> </span>

Abstract

A rapid and highly sensitive detection and quantification method for white spot syndrome virus (WSSV) was developed using GeneAmp 5700 Sequencer Detection System and SYBR Green chemistry. The RT-PCR mixture contained the fluorescent dye SYBR Green, which exhibited florescence enhancement upon binding to double strand cDNA. About 10⁵ and 10⁶ copies µg^-1 of viral DNA load were observed in the juvenile offsprings of shrimps (<i style="mso-bidi-font-style:normal">Litopenaeus vannamei</i>) originated from Hawaii (Hawaii A) and Singapore, respectively. The inocula of known virus content, derived from three different place of origin, <i style="mso-bidi-font-style:normal">viz.</i>, Hawaii (Hawaii-A), Singapore and Thailand, showed different logs of WSSV copies as 10⁷, 10⁶ and 10⁵WSSV copies ng^-1 at DNA, respectively. In the positive control, a higher amount DNA copies were noticed. An appropriate quantity of 10⁷, 10⁶ and 10⁵WSSV copies of ng^-1DNA was observed in the juvenile offsprings of shrimp, respectively originated from Hawaii-A, Singapore and Thailand. More importantly, there was no sign of WSSV load till the end of assay in the entire control group of juvenile offsprings. The least quantity of WSSV load (10⁵WSSV copies ng^-1) was recorded in the juvenile offsprings of <i style="mso-bidi-font-style:normal">L. vannamei</i> originated from Thailand.