Characterization of reticuloendotheliosis virus isolates obtained from broiler breeders, turkeys, and prairie chickens located in various geographical regions in the United States

Abstract

Nine reticuloendotheliosis virus (REV) isolates obtained from broiler breeders, turkeys, and prairie chickens located in three different geographical regions in the USA, and three isolates obtained from known contaminated live-virus vaccines were characterized using polymerase chain reaction (PCR) and indirect immunofluorescence (IFA) assays. All isolates were propagated in chicken embryo fibroblasts obtained from a specific pathogen free breeder flock. PCR analysis of all 12 isolates resulted in the amplification of the 291-bp REV long-terminal repeat region (LTR); none of the isolates exhibited a different pattern or shift from the expected PCR product of REV LTR. The subtype of the REV isolates was determined by IFA using REV-specific monoclonal antibodies, 11B118.22, 11C237.8, and 11D182. Results from sub-typing indicated that all nine isolates from broiler breeders, turkeys, and prairie chickens belonged to subtype 3, and are antigenically related to the chick syncytial virus (CSV) strain of REV, the prototype of subtype 3 REV. In contrast, the three isolates from contaminated vaccines were classified as subtype 2, and were antigenically related to spleen necrosis virus (SNV) strain of REV, the prototype of subtype 2 REV. Three isolates representing REV isolated from broiler breeders, turkeys, and prairie chickens were cloned and further evaluated by DNA sequence analysis of the envelope gene. Results from DNA sequence analysis confirmed those from sub-typing and indicated that the three REV isolates representing those from broiler breeders, turkeys, and prairie chickens are closely related to CSV of REV, with an amino acid homology of 98% or greater as compared with SNV with an amino acid homology of 95% or less. Data from this study clearly indicate that subtype 3 is the most common subtype of REV circulating in three different avian species, namely broiler breeders, turkeys and prairie chickens, located in three different geographical regions in the United States.

Detection and Molecular Characterization of a Natural Coinfection of Marek’s Disease Virus and Reticuloendotheliosis Virus in Brazilian Backyard Chicken Flock

“…The phylogenetic distribution for both genes is consistent with previous reports [9,37,38]. It has been shown that there is no correlation between time, place, or specific host in the distribution of REV; however, most of the strains reported, including the present study, belong to the REV3 subtype [39][40][41]. The occurrence of cases caused only by REV is infrequent.…”

Probable Congenital Transmission of Reticuloendotheliosis Virus Caused by Vaccination with Contaminated Vaccines

“…REV infection in chickens generally results in decrease of production performance and decline of immune function, and is likely to cause vaccination failure [12], [13]. REV is spread mainly through contact with infected poultry such as chickens, turkeys and ducks, and through insects as well [14], [15].…”

An atypical clinicopathological manifestation of fowlpox virus associated with reticuloendotheliosis virus in commercial laying hen flocks in Brazil

“…Reticuloendotheliosis virus (REV) is an enveloped single-stranded RNA virus that belongs to the genus Gammaretrovirus in the family Retroviridae (ICTV, 2019). REV is usually associated with different clinical manifestations, such as runting-stunting syndrome, chronic neoplasia of lymphoid and other tissues, acute reticulum cell neoplasia (reticuloendotheliosis) and immunodepression (Nair et al, 2013), in several domestic avian hosts, such as chickens, ducks, geese, turkeys and wild birds, such as Japanese quail, mallards, peafowl, pheasants, pigeons and prairie chickens (Bohls et al, 2006;Cheng et al, 2007;Drew et al, 1998;Lin, Chen, Wang, & Wang, 2009;Mays, Silva, Lee, & Fadly, 2010;Schat, Gonzalez, Solorzano, Avila, & Witter, 1976;Zavala, Cheng, Barbosa, & Haefele, 2006;Zhai et al, 2016). All REV strains are grouped closely according to serology, but they can be divided into three subtypes based on antibody reactivity (Chen, Cui, Lee, & Witter, 1987); they are represented by the prototype strains REV-T (Cook, 1969), SNV (Trager, 1959) and CSV (Cook, 1969), respectively.…”