biostudies-literatureFerreri LMNIAID NIH HHSInstituto Nacional de Tecnología Agropecuaria1182550https://www.ebi.ac.uk/biostudies/studies/S-EPMC10264679biostudies-literatureUnknown10Introduction of influenza A viruses (FLUAV) into poultry from waterfowl is frequent, producing economic burden and increasing the probability of human infections. We have previously described the presence of FLUAV in wild birds in Argentina with unique evolutionary trajectories belonging to a South American lineage different from the North American and Eurasian lineages. Adaptability of this South American lineage FLUAV to poultry species is still poorly understood. In the present report, we evaluated the capacity of an H4N2 FLUAV from the South American lineage to adapt to chickens after low number of passages. We found that five mutations were acquired after five passages in 3-days-old chickens. These mutations produced a virus with better infectivity in <i>ex vivo</i> trachea explants bFrontiers in veterinary scienceSouth American H4N2 influenza A virus improved replication in chicken trachea after low number of passages.PMC10264679HHSN272201400008CPNSA 1115052PNSA 1115056Ferreri LMRajao DCarnaccini SOlivera VPereda APerez DRfalseSouth American H4N2 influenza A virus improved replication in chicken trachea after low number of passages.Introduction of influenza A viruses (FLUAV) into poultry from waterfowl is frequent, producing economic burden and increasing the probability of human infections. We have previously described the presence of FLUAV in wild birds in Argentina with unique evolutionary trajectories belonging to a South American lineage different from the North American and Eurasian lineages. Adaptability of this South American lineage FLUAV to poultry species is still poorly understood. In the present report, we evaluated the capacity of an H4N2 FLUAV from the South American lineage to adapt to chickens after low number of passages. We found that five mutations were acquired after five passages in 3-days-old chickens. These mutations produced a virus with better infectivity in <i>ex vivo</i> trachea explants b2023-01-01T00:00:00Z20232026-05-29T19:25:08.86Z2025-04-19T20:48:11.257ZS-EPMC102646793732383710.3389/fvets.2023.1182550