Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 2013
Publication Date: N/A
Technical Abstract: Bovine parainfluenza virus type 3 (bPI3) is a member of the Paramyxoviridae, genus Respirovirus. bPI3 are pathogens commonly associated with bovine respiratory disease complex. Most infections are subclinical but they can cause acute respiratory disease characterized by cough, fever and nasal discharge. The presence of bPI3 with other respiratory pathogens can result in severe disease. To date, three genotypes of bPI3 have been identified. Genotype A viruses were reported primarily in North America, genotype B was reported in Australia, and genotype C was reported in China and South Korea. The US strains found in GenBank are all genotype A. bPI3 strains used in this study were isolated at the Texas A&M Veterinary Diagnostic Laboratory between 2007 and 2011. The near full-length genome sequences of the bPI3 viruses were determined using a next generation, Ion Torrent-based sequencing procedure where multiple viruses were sequenced simultaneously. The US genotype B and C viruses were only 82-84% similar to genotype A virus sequences found in GenBank. Similarly, genotypes B and C were only 82% similar to each other. Interestingly, the most closely related human PI3 strains were 80% similar. Comparison of the US genotype B viruses with the single full-length Australian virus sequence showed they were 94% similar, indicating some divergence from the original strain. The US genotype C viruses were 98% similar to the strain reported in South Korea. Of the 13 viruses with sequence, 1 was a genotype A virus, 3 were genotype B and 9 were genotype C. This is the first report of the presence of the B and C genotypes of bPI3 in the US. The A genotype has been replaced by the B and C genotypes as the predominant bPI3 viruses in the US. The implications of these findings will be discussed.