Browsing Department of Veterinary Medicine Research Works by Subject "Avian Influenza Virus"
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- ItemDetection of NP, N3 and N7 antibodies to avian influenza virus by indirect ELISA using yeast-expressed antigens(Springer Nature, 2009-10-07) Upadhyay, Chitra; Ammayappan, Arun; Vakharia, Vikram NAvian influenza viruses, belonging to the family Orthomyxoviridae, possess distinct combinations of hemagglutinin (H) and the neuraminidase (N) surface glycoproteins. Typing of both H and N antigens is essential for the epidemiological and surveillance studies. Therefore, it is important to find a rapid, sensitive, and specific method for their assay, and ELISA can be useful for this purpose, by using recombinant proteins. The nucleoprotein (NP) and truncated neuraminidase subtype 3 and 7 of avian influenza virus (AIV) were expressed in Saccharomyces cerevisiae and used to develop an indirect enzyme-linked immunosorbent assay for antibody detection. The developed assays were evaluated with a panel of 64 chicken serum samples. The performance of NP-ELISA was compared with the commercially available ProFlok® AIV ELISA kit. The results showed comparable agreement and sensitivity between the two tests, indicating that NP-ELISA assay can be used for screening the influenza type A antibody in AIV infected birds. The N3 and N7- ELISAs also reacted specifically to their type specific sera and did not exhibit any cross-reaction with heterologous neuraminidase subtype specific sera. The study demonstrates the expression of the NP, N3, and N7 proteins of AIV in yeast (S. cerevisiae) and their application in developing an indirect ELISA for detecting NP, N3 and N7 antibodies from AIV-infected chicken sera. The described indirect ELISAs are rapid, sensitive, specific and can be used as promising tests during serological surveillance.
- ItemPartial direct contact transmission in ferrets of a mallard H7N3 influenza virus with typical avian-like receptor specificity(Springer Nature, 2009-08-14) Song, Haichen; Wan, Hongquan; Araya, Yonas; Perez, Daniel RAvian influenza viruses of the H7 subtype have caused multiple outbreaks in domestic poultry and represent a significant threat to public health due to their propensity to occasionally transmit directly from birds to humans. In order to better understand the cross species transmission potential of H7 viruses in nature, we performed biological and molecular characterizations of an H7N3 virus isolated from mallards in Canada in 2001. Sequence analysis that the HA gene of the mallard H7N3 virus shares 97% identity with the highly pathogenic avian influenza (HPAI) H7N3 virus isolated from a human case in British Columbia, Canada in 2004. The mallard H7N3 virus was able to replicate in quail and chickens, and transmitted efficiently in quail but not in chickens. Interestingly, although this virus showed preferential binding to analogs of avian-like receptors with sialic acid (SA) linked to galactose in an α2–3 linkage (SAα2–3Gal), it replicated to high titers in cultures of primary human airway epithelial (HAE) cells, comparable to an avian H9N2 influenza virus with human-like α2–6 linkage receptors (SAα2–6Gal). In addition, the virus replicated in mice and ferrets without prior adaptation and was able to transmit partially among ferrets. Our findings highlight the importance and need for systematic in vitro and in vivo analysis of avian influenza viruses isolated from the natural reservoir in order to define their zoonotic potential.