Replication of parental and mutant TK04 viruses in human, pig and turkey primary tracheal/bronchial epithelial cells. Parental virus has Asp at residue 190 of the RBD, while the mutant virus has Ala at the corresponding position. A strain with Glu627Lys mutation in the PB2 gene was included in the kinetic study to serve as control, since such mutation was shown to affect host range specificity of influenza A viruses. Parental TK04-190Asp replicated more efficiently than the mutant TK04-190Ala in three cell types (P-values <0.0091, <0.0021, and <0.0119 for HAEC, PEC and TEC respectively). Mutation in the PB2 gene did not affect virus replication.