Occurrence and phylogenetic analysis of avipoxvirus isolated from birds around Jammu

Abstract

Domesticated fowls, pigeons and turkey birds were screened for avipoxvirus infection from different areas in Jammu region. Based on typical pox lesions the overall occurrence in fowl was found to be 18.52%, 17.03% in pigeons and 57.14% in turkeys. Mortality recorded in chicks was 41.96%, 45.36% in squabs, 100% in poults, and 20.00% in adult turkeys. Both cutaneous and diphtheritic forms of the disease was observed of which the latter was particularly prevalent in young birds. One sample of putative fowlpox virus (FWPV) from skin lesions of a fowl, and two samples of putative pigeonpox virus (PGPV) from skin and diphtheritic lesions each were inoculated on chorio-allantoic membrane (CAM) of 10–12 days old chicken embryonated eggs. A confirmatory diagnosis was made by PCR amplification of a highly conserved P4b gene locus detected in tissue samples from skin, diphtheritic membrane and virus inoculated CAM yielding a predicted 578 bp product. Phylogenetic analysis based on the same P4b gene locus revealed FWPV and turkeypox virus (TKPV) to be 99% related and belonging to clade 1, while PGPV was found to belong to clade 2. All three isolates illustrate considerable heterogeneity within the conserved P4b gene locus. The study indicates that the closely related FWPV and TKPV isolates may have the potential of cross infection between fowls and turkeys and therefore cross transmission studies are suggested.