Submitted to: Journal of Clinical Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/27/2002
Publication Date: N/A
Citation: N/A Interpretive Summary: Avian pneumovirus (APV) is an economically important pathogen of commercial turkeys that causes upper respiratory tract infections. The disease has been restricted to the north-central U.S. and occurs primarily during the spring (April to May) and autumn (October to December) months. Genetically all the U.S. viruses are closely related and are a distinct sub-group different from APV isolates from Europe. The U.S. viruses have evolved since first isolated as illustrated by an increased number of amino acid changes in the proteins of more recently isolated APV as compared to the original virus in the U.S.
Technical Abstract: Avian pneumovirus (APV) has been concentrated in the north-central region of U.S. The disease has seasonal incidence with 39% of the cases reported during the spring (April to May) and 40.8% during autumn (October to December). Comparison of the nucleotide sequences of nucleoprotein (N), phosphoprotein (P), matrix (M), fusion (F), and second matrix (M2) genes revealed between 89% and 94% nucleotide sequence identity, and predicted amino acid sequence identity of 81% to 95% among the U.S. isolates. In contrast, genes from U.S. viruses had 41% to 77% nucleotide sequence identity and 52% to 78% predicted amino acid sequence identity with European subgroup A or B viruses, confirming that U.S. viruses belong to a separate subgroup. There was evidence of positive selection between the first APV isolate (APV/CO) from the western region and viruses later isolated from the north-central region of U.S. (APV/MN 2A), as demonstrated by high nonsynonymous versus synonymous nucleotide substitutions in the F gene. Phylogenetic comparison of subgroups A, B, and C viruses indicated that subgroup A and B viruses were more closely related than either A or B viruses were to subgroup C viruses.