Role of Quail in the Interspecies Transmission of H9 Influenza A Viruses: Molecular Changes on HA That Correspond to Adaptation from Ducks to Chickens

Abstract

H9 influenza viruses have become endemic in land-based domestic poultry in Asia and have sporadically crossed to pigs and humans. To understand the molecular determinants of their adaptation to land-based birds, we tested the replication and transmission of several 1970s duck H9 viruses in chickens and quail. Quail were more susceptible than chickens to these viruses, and generation of recombinant H9 viruses by reverse genetics showed that changes in the HA gene are sufficient to initiate efficient replication and transmission in quail. Seven amino acid positions on the HA molecule corresponded to adaptation to land-based birds. In quail H9 viruses, the pattern of amino acids at these seven positions is intermediate between those of duck and chicken viruses; this fact may explain the susceptibility of quail to duck H9 viruses. Our findings suggest that quail provide an environment in which the adaptation of influenza viruses from ducks generates novel variants that can cross the species barrier.

A 27-Amino-Acid Deletion in the Neuraminidase Stalk Supports Replication of an Avian H2N2 Influenza A Virus in the Respiratory Tract of Chickens

“…The quantity of adaptive mutations necessary for an avian virus of a particular subtype to cross the species barrier is unknown. Our results are consistent with the notion that changes on the surface genes alone are insufficient for the transmission of avian influenza viruses in chickens (19,26,34,35). It should also be noted that the changes that occurred during adaptation in quail were maintained in 7 passages of the virus in chickens and were found to be necessary for transmission.…”

“…Japanese quail are typically more susceptible to aquatic influenza viruses than other terrestrial poultry. These viruses establish infection in the respiratory tract, and shedding occurs via aerosol (2,19,26,34,38,43). Quail have been implicated in the transmission of avian influenza viruses, such as H5N1 and H9N2 viruses, which have crossed the species barrier to infect humans (9,14,15,22,28).…”

Transmission of low-pathogenicity avian influenza virus of subtype H6N2 from chickens to Pekin ducks and Japanese quail (Coturnix coturnix japonica)

“…Previous AIV transmission studies in quail have had mixed results. Perez et al (2003), in their studies of Asian duck H9 AIV, did not observe transmission from inoculated to susceptible quail through either direct or indirect contact 5 to 7 days post inoculation, but did observe transmission of an Asian quail H9 AIV to quail and chickens with faecal contact. It is possible that transmission of the AIV subtypes studied by Perez et al would have been observed if the experiment were extended beyond 7 days post inoculation.…”

Evidence of H1 and H3 Influenza Virus Infection in Captive Birds in Tehran from November 2008 to February 2009

“…More importantly, pheasants can serve as a "carrier" of influenza A viruses because of their continuous asymptomatic infection (20). On the other hand, previous studies indicate that quails play a significant role in the interspecies transmission of influenza virus from ducks to chickens (21). Domestic poultry such as quail and chicken possess α2, 3 and α2, 6 sialic acid receptors that may help passage of avian influenza viruses from bird species (such as ducks with only α2, 3 sialic acid receptor) to human with predominant α2, 6 sialic acid receptors (22,23).…”