Submitted to: Virus Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 24, 1999
Publication Date: February 1, 2000
Citation: SEAL, B.S., SELLERS, H.S., MEINERSMANN, R.J. FUSION PROTEIN PREDICTED AMINO ACID SEQUENCE OF THE FIRST U.S. AVIAN PNEUMOVIRUS ISOLATE AND LACK OF HETEROGENEITY AMONG OTHER U.S. ISOLATES. VIRUS RESEARCH. 2000. Interpretive Summary: Avian pneumoviruses (APV) cause turkey rhinotracheitis (TRT) and have recently emerged in the U.S. where it was previously not found. Genetic analysis of the matrix (M) and fusion (F) protein genes among U.S. isolates of APV demonstrates that these viruses have spread from the west-central to north-central commercial turkey flocks in the U.S. Also, these viruses are eremaining relatively stable with very little change in their genetic makeup. The U.S. isolates of APV separate as a genetically distinct group compared to the European subtype A and B viruses. The data generated at the Southeast Poultry Research Laboratory in Athens, Georgia will help in production of diagnostic reagents for these commercially important viruses.
Technical Abstract: Avian pneumovirus (APV) was first isolated from the west-central U.S. following emergence of turkey rhinotracheitis (TRT) during 1996. Subsequently, several APV isolates were obtained from the north-central U.S. Matrix (M) and fusion (F) protein genes of these isolates were examined for sequence heterogeneity and compared with European APV subtypes sA and B. Among U.S. isolates the M gene shared greater than 98% nucleotid sequence identity with only one nonsynonymous change occurring in a single U.S. isolate. Although the F gene among U.S. APV isolates shared 98% nucleotide sequence identity, nine conserved substitutions were detected in the predicted amino acid sequence. The F protein predicted amino acid sequence of the U.S. APV isolates had 72% sequence identity to the APV subtype A protein and 71% sequence identity to the F protein of APV subtype B. This compares with 83% sequence identity between the APV subtype A and B predicted amino acid sequences of the F protein. The U.S. isolates separate phylogenetically from their European counterparts based on F gene nucleotide or predicted amino acid sequences. Lack of sequence heterogeneity among U.S. APV subtypes indicates these viruses have maintained a relatively stable population since the first outbreak of TRT. Phylogenetic analysis of the F protein among APV isolates supports classification of the U.S. isolates as a new APV subtype C.