Molecular characterization of H3N2 influenza A viruses isolated from Ontario swine in 2011 and 2012

Grgić, Helena; Costa, Márcio Paulino; Friendship, Robert; Carman, Susy; Nagy, Éva; Wideman, Greg; Weese, Scott; Poljak, Zvonimir

doi:10.1186/s12985-014-0194-z

Cited by 14 publications

(29 citation statements)

References 33 publications

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“…1). Many of these variations are within known antigenic domains, e.g., antigenic sites A, B, C, D, and E (18,(25)(26)(27). Among these, 4 are in antigenic site A, whereas 10 are in antigenic site B.…”

Section: Resultsmentioning

confidence: 99%

“…Outbreaks of TRIG-H3N2 virus infections in U.S. swine were first reported in a few states in 1998 and have spread to many other states (11) and Canada (17,18). The current circulating swine H3N2 viruses in North America, together with A(H3N2)v viruses, were termed "lineage IV" based on the phylogenetic analysis with earlier swine H3N2 isolates (13,(17)(18)(19). The majority of A(H3N2)v isolates since 2011 have acquired the matrix gene from the 2009 pandemic H1N1 virus (2,20), which has enhanced the replication and transmission of A(H3N2)v viruses in swine (21,22), potentially increasing the risk of human infection.…”

mentioning

confidence: 99%

“…After multiple reassortment events in swine, these H3N2 viruses acquired a triple-reassortant internal gene (TRIG) cassette containing internal genes from avian, swine, and human strains (11,(14)(15)(16). Outbreaks of TRIG-H3N2 virus infections in U.S. swine were first reported in a few states in 1998 and have spread to many other states (11) and Canada (17,18). The current circulating swine H3N2 viruses in North America, together with A(H3N2)v viruses, were termed "lineage IV" based on the phylogenetic analysis with earlier swine H3N2 isolates (13,(17)(18)(19).…”

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confidence: 99%

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Amino Acids in Hemagglutinin Antigenic Site B Determine Antigenic and Receptor Binding Differences between A(H3N2)v and Ancestral Seasonal H3N2 Influenza Viruses

Wang

Ilyushina

Lugovtsev

et al. 2017

J Virol

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Influenza A H3N2 variant [A(H3N2)v] viruses, which have caused human infections in the UnitedStates in recent years, originated from human seasonal H3N2 viruses that were introduced into North American swine in the mid-1990s, but they are antigenically distinct from both the ancestral and current circulating H3N2 strains. A reference A(H3N2)v virus, A/Minnesota/11/2010 (MN/10), and a seasonal H3N2 strain, A/Beijing/32/1992 (BJ/92), were chosen to determine the molecular basis for the antigenic difference between A(H3N2)v and the ancestral viruses. Viruses containing wild-type and mutant MN/10 or BJ/92 hemagglutinins (HAs) were constructed and probed for reactivity with ferret antisera against MN/10 and BJ/92 in hemagglutination inhibition assays. Among the amino acids that differ between the MN/10 and BJ/92 HAs, those in antigenic site A had little impact on the antigenic phenotype. Within antigenic site B, mutations at residues 156, 158, 189, and 193 of MN/10 HA to those in BJ/92 switched the MN/10 antigenic phenotype to that of BJ/ 92. Mutations at residues 156, 157, 158, 189, and 193 of BJ/92 HA to amino acids present in MN/10 were necessary for BJ/92 to become antigenically similar to MN/ 10. The HA amino acid substitutions responsible for switching the antigenic phenotype also impacted HA binding to sialyl receptors that are usually present in the human respiratory tract. Our study demonstrates that antigenic site B residues play a critical role in determining both the unique antigenic phenotype and receptor specificity of A(H3N2)v viruses, a finding that may facilitate future surveillance and risk assessment of novel influenza viruses. IMPORTANCE Influenza A H3N2 variant [A(H3N2)v] viruses have caused hundreds of human infections in multiple states in the UnitedStates since 2009. Most cases have been children who had contact with swine in agricultural fairs. These viruses originated from human seasonal H3N2 viruses that were introduced into the U.S. swine population in the mid-1990s, but they are different from both these ancestral viruses and current circulating human seasonal H3N2 strains in terms of their antigenic characteristics as measured by hemagglutination inhibition (HI) assay. In this study, we identified amino acids in antigenic site B of the surface glycoprotein hemagglutinin (HA) that explain the antigenic difference between A(H3N2)v and the ancestral H3N2 strains. These amino acid mutations also alter binding to minor human-type glycans, suggesting that host adaptation may contribute to the selection of antigenically distinct H3N2 variants which pose a threat to public health.

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Section: Resultsmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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Amino Acids in Hemagglutinin Antigenic Site B Determine Antigenic and Receptor Binding Differences between A(H3N2)v and Ancestral Seasonal H3N2 Influenza Viruses

Wang

Ilyushina

Lugovtsev

et al. 2017

J Virol

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“…A substantial number of aa substitutions have been observed in previously identified antigenic sites and substitutions are presented in Figure 5 and Table S1. The most changes, were observed when 13 Canadian H3N2 viruses were compared with an Ontario virus from 2011, (A/SW/ON/103-18/11/H3N2) [15]. The number of aa changes relative to the latter virus for each antigenic site is also displayed in Figure 6.…”

Section: Resultsmentioning

confidence: 99%

“…In more recent studies, the A(H1N1)pdm09 has been identified as the most prevalent H1N1 virus in Ontario swine [12], and H1N2 reassortants have been documented [12,13]. Different types of novel H3N2 reassortants have been documented in several different studies [14,15], as well as ongoing circulation of the trH3N2 virus [15,16]. …”

Section: Introductionmentioning

confidence: 99%

Virological Surveillance of Influenza A Subtypes Isolated in 2014 from Clinical Outbreaks in Canadian Swine

Grgić

Gallant²,

Poljak

2017

Viruses

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Influenza A viruses (IAVs) are respiratory pathogens associated with an acute respiratory disease that occurs year-round in swine production. It is currently one of the most important pathogens in swine populations, with the potential to infect other host species including humans. Ongoing research indicates that the three major subtypes of IAV—H1N1, H1N2, and H3N2—continue to expand in their genetic and antigenic diversity. In this study, we conducted a comprehensive genomic analysis of 16 IAVs isolated from different clinical outbreaks in Alberta, Manitoba, Ontario, and Saskatchewan in 2014. We also examined the genetic basis for probable antigenic differences among sequenced viruses. On the basis of phylogenetic analysis, all 13 Canadian H3N2 viruses belonged to cluster IV, eight H3N2 viruses were part of the IV-C cluster, and one virus belonged to the IV-B and one to the IV-D cluster. Based on standards used in this study, three H3N2 viruses could not be clearly classified into any currently established group within cluster IV (A to F). Three H1N2 viruses were part of the H1α cluster.

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Influence of microclimate conditions on the cumulative exposure of nursery pigs to swine influenza A viruses

Ferreira

Grgić

Friendship

et al. 2017

Transbound Emerg Dis

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SummaryThe objective of this study was to investigate the association between environmental temperature and humidity and the presence of antibodies for two specific strains of swine influenza viruses: A/SW/ON/105-56/12/H3N2 (H3N2_D) and A/SW/ON/ 84/2012/H1N1 (H1N1_P). A cross-sectional study was performed in a commercial farm, and a total of 450 pigs at 10 weeks of age were blood sampled, by sampling 10 pigs per week for 45 weeks corresponding to 45 batches. Exposure of pigs to H3N2_D and H1N1_P virus was assessed by haemagglutination inhibition assay (HI), and a result of ≥1:40 was considered as indication of a positive exposure status for a specific strain. The selection of those two viruses was based on the fact that H1N1 was the dominant virus in Ontario herds, and H3N2 had been previously isolated in this particular farm. Environmental conditions were recorded through a portable device every 5 min and then summarized using descriptive statistics. The association between HI titres and environmental microconditions, in the nursery, was evaluated through random effect linear and logistic regression. The results showed that the prevalence for H1N1_P was high throughout the study (≥70%); however, for H3N2_D, the seroprevalence declined by the end of the study period.Results also showed an association between cumulative exposure to the viruses and temperature and relative humidity (p < .05). These results suggest that microclimate conditions can influence transmission patterns of influenza viruses in swine barns, and that even a herd with relatively simple demographics could have persistent and cocirculation of two different influenza A viruses IAV strains.antibodies, cocirculation, environment microclimate, humidity, swine influenza virus, Therefore, the objective of this study was to investigate the association between environmental temperature and humidity and the presence of antibodies for two specific strains of influenza viruses during the nursery phase of pig production. | MATERIALS AND METHODS | General overviewA 650-sow farrow-to-nursery farm located in southern Ontario was chosen for the study. The farrowing rooms and nursery rooms were operated in an all-in/all-out basis. Replacement gilts were purchased every 6 weeks from a single source and moved directly into the herd, with no prior off-site isolation. The farrowing area con- | Study populationA repeated cross-sectional study was performed between 18 April 2013 and 23 May 2014 in the nursery area. Each week during the study period, 10 pigs from the nursery room that held the oldest pigs, about 10 weeks of age, were selected for blood sampling. Sample size was sufficient to detect seroprevalence of 30% with 95%confidence, even with assay sensitivity that would be as low as 90%and 100% specificity. Such prevalence was considered as sufficient for the purposes of this study because of the timing of sampling (i.e., end of nursery) and the cumulative nature of the measured outcome (i.e., relatively long duration of antibodies). Two conveniently selected...

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Molecular characterization of H3N2 influenza A viruses isolated from Ontario swine in 2011 and 2012

Cited by 14 publications

References 33 publications

Amino Acids in Hemagglutinin Antigenic Site B Determine Antigenic and Receptor Binding Differences between A(H3N2)v and Ancestral Seasonal H3N2 Influenza Viruses

Amino Acids in Hemagglutinin Antigenic Site B Determine Antigenic and Receptor Binding Differences between A(H3N2)v and Ancestral Seasonal H3N2 Influenza Viruses

Virological Surveillance of Influenza A Subtypes Isolated in 2014 from Clinical Outbreaks in Canadian Swine

Influence of microclimate conditions on the cumulative exposure of nursery pigs to swine influenza A viruses

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