Interspecies and intraspecies transmission of triple reassortant H3N2 influenza A viruses

Abstract

The triple reassortant H3N2 viruses were isolated for the first time from pigs in 1998 and are known to be endemic in swine and turkey populations in the United States. In 2004, we isolated two H3N2 triple reassortant viruses from two turkey breeder flocks in Ohio and Illinois. Infected hens showed no clinical signs, but experienced a complete cessation of egg production. In this study, we evaluated three triple reassortant H3N2 isolates of turkey origin and one isolate of swine origin for their transmission between swine and turkeys. Although all 4 viruses tested share high genetic similarity in all 8 genes, only the Ohio strain (A/turkey/Ohio/313053/04) was shown to transmit efficiently both ways between swine and turkeys. One isolate, A/turkey/North Carolina/ 03, was able to transmit from pigs to turkeys but not vice versa. Neither of the other two viruses transmitted either way. Sequence analysis of the HA1 gene of the Ohio strain showed one amino acid change (D to A) at residue 190 of the receptor binding domain upon transmission from turkeys to pigs. The Ohio virus was then tested for intraspecies transmission in three different avian species. The virus was shown to replicate and transmit among turkeys, replicate but does not transmit among chickens, and did not replicate in ducks. Identifying viruses with varying inter-and intra-species transmission potential should be useful for further studies on the molecular basis of interspecies transmission.

Pathogenicity and Transmission in Pigs of the Novel A(H3N2)v Influenza Virus Isolated from Humans and Characterization of Swine H3N2 Viruses Isolated in 2010-2011

“…In human H3 viruses, amino acid positions D190, L/I226, and S228 correlated with SA␣-2,6 receptors, while in swine H3 viruses those positions are D/A190, V226, and S228 (27,40,46). All three isolates-A/IN A(H3N2)v, Sw/PA H3N2-TRIG, and Sw/IL rH3N2p-were able to infect and transmit to contact pigs.…”

Modifications in the Polymerase Genes of a Swine-Like Triple-Reassortant Influenza Virus To Generate Live Attenuated Vaccines against 2009 Pandemic H1N1 Viruses

“…The ty/04 strain is an ideal candidate for an att vaccine backbone, because this virus has been shown to replicate in several animal species, such as chickens, turkeys, and swine (76). We altered the PB2 and PB1 genes of ty/04 by incorporating ts mutations in both genes, and we also incorporated the HA tag into PB1 (Fig.…”

The Molecular Determinants of Antibody Recognition and Antigenic Drift in the H3 Hemagglutinin of Swine Influenza A Virus

“…) is a prototypic swine origin clade IV virus that grows well in cell culture, infects and transmits efficiently in pigs, and is amenable to genetic manipulations using a reverse genetics system (17,18,33). One substitution or combinations of up to four substitutions per mutant were introduced into the HA based on previous findings showing that six positions (positions 145, 155, 156, 158, 159, and 189) played a role in major antigenic changes in wild-type swine H3 viruses circulating in the United States (8).…”