Identification and genetic analysis of the recent Avian pox viruses from infected pigeons and chickens

Abstract

Background

Avian pox viruses (APVs) are highly contagious poultry diseases, posing a major economic threat to poultry production systems, and have a high mortality rate among young birds, Infected birds also face condemnation of affected carcasses due to the unsightly appearance of the nodular skin lesions.

This study aimed to provide an overview of the current genetic status of APV in backyard poultry, with a focus on the commercially available vaccines. To achieve this, molecular characterization and phylogenetic analysis of APVs were conducted, comparing their sequences with vaccine strains used in Egypt.

Results

The polymerase chain reaction (PCR) assay was able to detect APV in all the tested samples; 12 positive samples (6 chicken flocks and 6 pigeon flocks) were selected for DNA sequencing. The sequences were submitted to GenBank with accession numbers OR027032 to OR027043. The chicken strains exhibited 100% nucleotide identity with commercially available fowl pox virus (FPV) vaccines and were phylogenetically clustered within subclade A1 with other FPVs. On the other hand, the pigeon pox virus (PPV) strains were closely related to other PPV strains within subclade A2 and showing 100% and 91% nucleotide identity with the PPV and the FPV vaccines, respectively.

Conclusions

Despite the availability of APV vaccines in Egypt, a persistent threat of APV to poultry in the backyard system remains a significant concern. Our molecular characterization revealed the high genetic similarity between our field strains and commercially available vaccine strains, suggesting an urgent need for vaccination in backyard systems to counteract this emerging threat to bird populations.