Development of a generic avian flu viruses dipstick for on-site screening
AIV, as all viruses with negative-sense RNA genomes encode a single-strand RNA-binding nucleoprotein (NP). The primary function of NP is to encapsidate the virus genome for purposes of RNA transcription, replication and packaging. NP also functions as a key adapter molecule between virus and host cell processes. It is also estimated, that NP is the most conservative protein in AIV proteins tile.
As was determined previously, all negative-sense RNA virus genomes encodes three polypeptides, that forms the virus core, and are common to all families: an integral membrane glycoprotein, an RNA-dependent RNA polymerase and a single-strand RNA (ssRNA) binding protein, i.e. nucleoprotein, NP. The recent AIV diagnostic reports confirms, that NP is the most specific virus antigen, regarding immune response to various virus strains, sub-strains and virus geographic isolates (1).
This protein may be produced both in prokaryotic and eukaryotic expression systems in vitro (2, 3). The NP protein has estimated sites for phosphorylation, so the baculovirus expression system of insect cells, which provides the synthesis of fully processed and folded recombinant proteins, seemed to be more advantageous for generation of AIV protein antigen similar to native NP.
Therefore a recombinant Nucleoprotein common to Avian flu virus family has recently been produced, as Monoclonal antibodies targetting it.
These highly specific Mabs are being used in a new test format usable on-site by veterinarians for:
- generic screening of avian flu contaminated poultry or wild bird carcasses
- generic screening of biological aerosols sampled in confined poultry, or turkey farms sampled with high-flow wet cyclone technology, this high-flow wet cyclone airsampling SpinCon based technology validated for animal virus collected in aerosols in confined environment (Foot and mouth virus collection report)
The aim of the dipstick is to avoid unecessarily to trigger an alert with dead bird carcasses of bird due to natural death, or non avian pathogens contamination. use of this dipstick for sorting out dead bird carcasses will avoid the use of costly analytical Rt-PCR Primers when not necessary.
Will the disptick generic avian flu viruses detection kit be enough sensitive to detect avian flu viruses in dead bird carcasses?
Yes, according to US Department of Agriculture and other Ministries in charge of avian flu crisis in South East Asia, the concentration in beaks or feces is sufficient to give a positive signal with highly specific Monoclonal antibodies.
Any laboratory part of the O.I.E network of laboratories located in Europe not already contacted are welcomed to contact us for dipstick evaluation with their own strains. Scientific bibliography available on request.
Download the technical files of gereric avian flu diagnostic test kit: