The application of molecular methods in the identification of isolated strains of parainfluenza 3 virus of cattle

Bovine parainfluenza 3 virus (PI3) causes respiratory infections in cattle and sheep with great economic losses in livestock. The aim of this investigation was to determine the significance of molecular methods in the identification of isolated strains of PI3 virus. Twenty cattle nasal swabs were analyzed for the presence of PI3 using the standard virology method of virus isolation in MBDK cell line and virus neutralization test. The identification of isolated strains was confirmed by RT-PCR and method of direct sequencing with primers for PI3 fusion (F) protein gene. PI3 virus was isolated and identified in four nasal swabs using the standard virology method and RT-PCR. The analysis of nucleotide sequences of isolated PI3 strains showed high similarity with sequences isolated from cattle in Asia. Our results showed that molecular methods are very useful in the diagnosis of PI3 infections as well as for the identification and characterization of PI3 strains in Serbia. [Projekat Ministarstva nauke Republike Srbije, br. 31008 i br. 175073]