Insights into pathological and molecular characterization of avipoxviruses circulating in Egypt

ABSTRACT

1. Avipoxvirus (APV) infections are one of many threats inflicting economic losses within the poultry industry, particularly in tropical and subtropical countries. A proper and comprehensive study for APVs is needed to increase the knowledge concerning the diversity and evolution of the virus.

2. For this purpose, 136 bird flocks of different species and breeding types were examined for APV infection between October 2016 and November 2017. One hundred and thirty samples had visible pocks on the chorioallantoic membrane (CAM) which were designated as fowl pox-like viruses via amplification of 578 bp from the P4b gene and 1800 bp from the fpv140 locus.

4. A comprehensive phylogenetic analysis of fpv167 locus (P4b), fpv140 locus (fpv139 and fpv140) and fpv94 (DNA polymerase) revealed that all the analysed strains belong to fowl pox-like viruses (clade A; subclade A1 and A2). Based on the fpv140 locus full nucleotide sequence, three turkey originated strains were seen to be divergent from chicken originated sequences and branched into novel subclade A1.b.

5. Trees comparison, within the term of speculation of virus-host specificity, clearly highlighted a high order specific subgrouping among subclades in the case of the fpv140 locus (including fpv139 and fpv140). Hence, the fowl poxvirus, turkey poxvirus and pigeon poxvirus strains clustered into distinct host-specific subclades A1a, A1.b and A2, respectively, which could not be seen in the FWPV-P4b and DNA polymerase phylogeny.

KEYWORDS:

• Avipoxviruses
• Egypt
• P4b
• fpv140
• DNA polymerase

Authors contributions

Mohamed Lebdah designed and directed the project as well as revised the final version of the manuscript. Amira Ali did the samples collection and virus works. Abdel-Moneim Ali performed all the histopathology works and analysed the output data. Ola Hassanin performed molecular biology works and computational bioinformatic analysis as well as manuscript writing with input from all authors.

Disclosure statement

No potential conflict of interest was reported by the authors.

Ethics statement

All the animal work included in this study underwent ethical review and was given approval by the local animal welfare regulation on experiments with chickens and similar species and a head of the Ethics Committee for Animal Studies at the Faculty of Veterinary Medicine, Zagazig University, Egypt.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.