The infection of turkeys and chickens by reassortants derived from pandemic H1N1 2009 and avian H9N2 influenza viruses.

Outbreaks of pandemic H1N1 2009 (pH1N1) in turkeys have been reported in several countries. Co-infection of pH1N1 and avian H9N2 influenza viruses in turkeys provide the opportunity for their reassortment, and novel reassortant viruses might further be transmitted to other avian species. However, virulence and transmission of those reassortant viruses in poultry remain unclear. In the present study, we generated 16 single-gene reassortant influenza viruses including eight reassortants on the pH1N1 background by individual replacement with a corresponding gene segment from H9N2 and eight reassortants on the H9N2 background replaced individually with corresponding gene from pH1N1, and characterized reassortants viruses in turkeys and chickens. We found that the pH1N1 virus dramatically increased its infectivity and transmissibility in turkeys and chickens after introducing any gene (except for PB2) from H9N2 virus, and H9N2 virus acquired single gene (except for HA) of pH1N1 almost did not influence its replication and transmission in turkeys and chickens. Additionally, 13 reassortant viruses transmitted from turkeys to chickens. Our results indicate that turkeys and chickens are susceptible to pH1N1-H9N2 reassortant viruses, and mixing breeding of different avian species would facilitate the transmission of these reassortant viruses.

据报道，多个国家的火鸡中爆发了2009年甲型H1N1流感（pH1N1）。火鸡中pH1N1和禽H9N2流感病毒的共感染为它们的重配提供了机会，新的重配病毒可能会进一步传播给其他禽类。然而，这些重配病毒在家禽中的致病性和传播性仍不清楚。在本研究中，我们通过用H9N2的相应基因片段逐个替换，产生了16种单基因重配流感病毒，其中包括8种在pH1N1背景上的重配病毒，以及通过用pH1N1的相应基因逐个替换，产生了8种在H9N2背景上的重配病毒，并对火鸡和鸡中的重配病毒进行了特性研究。我们发现，在引入H9N2病毒的任何基因（PB2除外）后，pH1N1病毒在火鸡和鸡中的感染性和传播性显著增强，而H9N2病毒获得pH1N1的单基因（HA除外）几乎不影响其在火鸡和鸡中的复制和传播。此外，有13种重配病毒从火鸡传播到了鸡。我们的研究结果表明，火鸡和鸡对pH1N1 - H9N2重配病毒易感，不同禽类的混养会促进这些重配病毒的传播。