An Indigenous, Field-Deployable, Lateral Flow Immunochromatographic Assay Rapidly Detects Infectious Myonecrosis in Shrimp, Litopenaeus vannamei.

ABSTRACT

Shrimp farming is an important socioeconomic activity worldwide. Infectious myonecrosis virus (IMNV) is an important shrimp virus responsible for significant mortality (up to 70%) in Litopenaeus vannamei. We produced recombinant capsid protein (r-IMNV31) and obtained a highly specific antibody, anti-r-IMNV31, which was used in WOAH-approved ELISA and Western blot to detect IMNV. Further, anti-r-IMNV31 was employed in an indigenously developed lateral flow immunoassay (LFA) with gold nanoparticles as a visual label. Using LFA, IMNV could be detected rapidly (20 min) from tissue homogenate with high specificity, reproducibility, and sensitivity (LOD = 103 viral particles). LFA was validated with "gold standard" qRT-PCR using 60 samples with high sensitivity (100%), specificity (86%). A Cohen's kappa coefficient of 0.86 suggested "good agreement" between LFA and qRT-PCR. With a shelf-life of ~ 1 year at ambient temperature, the use of LFA in the on-site detection of IMNV by shrimp farmers will be a reality.