Molecular Detection of Reticuloendotheliosis Virus (REV) Integration in Avian Poxvirus in North Eastern India

Abstract

Avipoxviruses are responsible for decreased egg production, reduced growth and increased mortality in poultry. The disease has re-emerged as a new threat to poultry farmers as a number of outbreaks have been reported worldwide. Several workers have characterized the field strains of fowlpox virus and found incorporation of reticuloendotheliosis (REV) provirus in their genome. Here, the authors present the cases of poxvirus infection in three avian species viz., poultry, turkey and pigeon in north eastern India and found REV genes within the genome of poxvirus isolated from poultry and turkey. The presence of REV in the flocks of the region need to be further investigated as it reflects the emerging threats to the poultry industry at large and poultry rearing in the region in particular.

The Seroprevalence Study of Reticuloendotheliosis Virus Infection in Chicken in Bangladesh

“…REV can cause immunesuppression, lymphoma and runting disease [3], and clinically showed nodular tumors in the liver, lung, kidney, pancreas, and retarded the normal growth of birds [7]. REV has worldwide distribution including India, neighbor country of Bangladesh [8,9]. Several studies also identified the incorporation of REV provirus in the genome of fowlpox virus [10,11].…”

Molecular Detection of Reticuloendotheliosis Virus 5′ Long Terminal Repeat Integration in the Genome of Avipoxvirus Field Strains from Different Avian Species in Egypt

“…Similar results were reported by Masola et al (2014) [ 67 ], who confirmed the integration of REV in 53 out of 55 tested FWPV isolates. In other studies [ 25 ], REV-5′LTR was detected in FWPV and TKPV genomes. Similar results were reported in relation to the integration of REV sequences into the FWPV and TKPV genomes [ 54 , 68 , 69 ].…”

“…In the same line, the sequence analysis of our APV P4b gene showed 100% identical DNA sequences to that reported in a previous study [ 59 ], while showing 71–100% similarity in nucleotide sequences between different species of APVs [ 22 , 24 ]. However, FWPV and TKPV seem to be identical, as they produced identical restriction patterns [ 25 ]; some researchers suggested that the TKPV is a different strain based on the difference in genome sizes (288.54 Kbp for FWPV versus 188.53 Kbp for TKPV) and the susceptibility of ducks to TKPV but not FWPV [ 60 , 61 , 62 , 63 ]. Additionally, the difference in physical and chemical properties, cross-protection, and phylogenetic analysis might support the theory that suggests that the TKPV is different from FWPV [ 17 , 39 , 64 , 65 ].…”

“…Additionally, the difference in physical and chemical properties, cross-protection, and phylogenetic analysis might support the theory that suggests that the TKPV is different from FWPV [ 17 , 39 , 64 , 65 ]. In accordance with PGPV, it was considered to be different from FWPV, as they showed host specificity and different profiles with the nucleotide sequence analysis of the P4b gene [ 24 , 25 , 66 ]. Interestingly, the mans17P isolate identified in the present study showed 100% identity to other PGPVs obtained from GenBank, while the PGPV identified in this study was different from FWPV (mans17F), TKPV (mans17T), and CNPV (mans17C), with 91.7% identity and 44 nucleotide substitutions [ 4 , 22 , 44 ].…”

“…Over 50 years ago, researchers detected the reticuloendotheliosis virus sequence integration in the fowlpox virus (FWPV), pigeonpox virus (PGPV), and turkeypox virus (TKPV) genomes [25][26][27]. Full infective reticuloendotheliosis virus (REV) provirus integration in poxvirus genomes has been associated with immunosuppression, virulence enhancement, and the dissemination of REV, which occurs as a consequent exacerbated progression of the disease [25,28]. In spite of REV provirus integration in most field strains of fowlpox virus (FWPV), vaccine strains only contain long terminal repeats remnants [26].…”