Phylogenetic characterization of the fusion genes of the Newcastle disease viruses isolated in Fars province poultry farms during 2009-2011.

Despite routine vaccination programs against Newcastle disease (ND), sporadic cases have occasionally occurred that remain a constant threat to commercial poultry. Ten isolates of Newcastle disease viruses (NDV) from infected broiler chicken cases were obtained from various locations in Fars province during 2009-2011 and genetically analyzed using reverse transcription polymerase chain reaction (RT- PCR) with primers specific to the viral fusion (F) protein- gene. The viruses were confirmed as NDV by hemagglutination inhibition assay and RT- PCR.