Kamolwan Watcharatanyatip. Development of a double-antigen sandwich ELISA using recombinant nucleoprotein for detecting antibodies to influenza a viruses. Master's Degree(Immunology). Mahidol University. Mahidol University Library and Knowledge Center. : Mahidol University, 2009.
Development of a double-antigen sandwich ELISA using recombinant nucleoprotein for detecting antibodies to influenza a viruses
Abstract:
Influenza A virus infection has emerged as one of the major threats to
human and animal health. The current outbreak of avian influenza virus of the H5N1
type in animals has the potential to cause new influenza pandemics which may have
devastating results. Serological surveillance, including serologic detection of
antibodies to avian influenza virus (AIV), is of great importance in preventing and
controlling avian influenza. In the present study, a double-antigen sandwich ELISA
was developed for the detection of antibodies to influenza A viruses. A recombinant
nucleoprotein (rNP) of influenza A virus was used as a captured antigen and also as an
HRP-conjugate for detecting the antibodies. Sera from chickens, geese, open-billed
storks, ducks, lesser whistling ducks, and pigeons were tested. A total of 138 serum
samples (avian species) with known antibody status were tested with the ELISA. The
sensitivity of ELISA was 95.6%, and the specificity 97.3% was obtained. The assay
was able to detect the presence of influenza A antibodies as early as 4 days post
inoculation in ducks, experimentally infected with influenza A (H5N1) virus. There
was a good correlation (rs = 0.84) between the double-antigen sandwich ELISA and
the hemagglutination inhibition (HI) test. Excellent agreement 97.8% was obtained
between the two tests (κ = 0.96). Human sera were also tested with this assay. The
double-antigen sandwich ELISA results showed that this assay was able to detect
additional positive samples that were negative by the HI. These results indicated that
the double-antigen sandwich ELISA based on rNP may offer an effective screening
method for the serodiagnosis of influenza A virus. This ELISA also enables the
detection of antibodies to influenza A viruses in multi species without a need for
species-specific secondary antibodies