molecular detection and phylogenetic analysis of avipoxvirus strains isolated from different bird species

the polymerase chain reaction (pcr) was used to amplify a 578 bp fragment of the poxvirus 4b core protein. avipoxvirus (apv) specific dna was detected in all 10 different isolates (each of which had been isolated from an epidemic) isolated from chicken; canary and mynah were collected from tehran province. sequencing was performed for 2 isolates as representative and the nucleotide sequence showed a similarity of 71-100% with the other sequences in the genbank. the derived phylogenetic tree showed six distinguishable sequence clusters. the sequence analysis reveals that the iranian isolates are within the cluster with highly conserved p4b core protein in different countries and species of birds. concerning the distance between countries which is the origin of the studied isolates that are situated in the same cluster with our iranian isolates, nearly the same identity (95-99%) of isolates in this cluster exist, and so potential of infectivity of the isolates in several species and regions, and the import and export of birds from all over the world can likely spread the virus to other countries. hence, strict quarantine measures should be  considered in the entrances of every country. moreover, this is the first molecular study in avipoxviruses in iran, especially in exotic birds.