DAO 57:193-200 (2003)  -  doi:10.3354/dao057193

Detection and differentiation of yellow head complex viruses using monoclonal antibodies

Chumporn Soowannayan1, Timothy W. Flegel1,*, Paisarn Sithigorngul2, Joanne Slater3, Alexander Hyatt3, Sandy Cramerri3, Terry Wise3, Mark St. J. Crane3, Jeff A. Cowley4, Russell J. McCulloch4, Peter J. Walker4

1National Center for Genetic Engineering and Biotechnology, and Centex Shrimp Chalermprakiat Building, Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
2Dept. of Biology, Faculty of Science, Srinakarinwirot University, Sukhumvit Soi 23, Bangkok 10110, Thailand
3CSIRO Livestock Industries, Australian Animal Health Laboratory, PO Bag 24, Geelong, Victoria 3220, Australia
4CSIRO Livestock Industries, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia, Queensland 4067, Australia
*Corresponding author. Email:

ABSTRACT: Three monoclonal antibodies (MAbs) raised against pathogenic yellow head virus (YHV) from Thailand were tested against tissues of shrimp from Thailand, Australia, Ecuador and India that were purported to be infected with yellow head complex viruses. MAbs V-3-2B and Y-18 were specific to gp116 and gp64 envelope proteins, respectively, while Y-19 was specific to a 20 kDa putative nucleoprotein p20. As a preliminary step, the site of reactivity of the 3 MAbs in YHV was determined by immuno-electron microscopy using ultra-thin sections of YHV-infected shrimp tissue and negatively stained, semi-purified YHV particles. As expected, MAb Y-19 reacted with viral nucleocapsids in ultra-thin sections but not with negatively stained, whole virions; MAb V-3-2B did react with negatively stained, whole virions, but not with virions or nucleocapsids in ultra-thin sections. Unexpectedly, MAb Y-18 did not react with whole or sectioned virions. By immunohistochemistry, MAbs Y-19 and Y-18 reacted with Penaeus monodon tissues infected with either YHV or with gill-associated virus (GAV) from Australia, while MAb V-3-2B reacted with YHV only. In addition, all the YHV and GAV tissue samples gave positive in situ hybridization reactions with a cDNA probe specific to the ORF1b gene of YHV. They also gave expected differential RT-PCR results for YHV and GAV. By contrast, 2 natural Thai shrimp specimens with no gross signs of disease gave similar immunohistochemical reactions and RT-PCR reactions to GAV. However, sequencing of their RT PCR products showed that they shared 92.7% identity with GAV, but only 79.0% identity with YHV. Although specimens from Ecuador and India displayed histopathology suggestive of YHV infection, they gave negative immunohistochemical reactions with all 3 Mabs, and negative in situ hybridization results. Additional work is required to determine whether a virus from the yellow head complex was responsible for their observed histopathology. These data show that the 3 YHV MAbs could be used in diagnostic situations to differentiate some viruses in the yellow head virus complex.

KEY WORDS: Yellow head virus · YHV · Monoclonal antibody · Differential detection · Gill associated virus · GAV

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