Antigenic and genomic characterization of turkey enterovirus-like virus (North Carolina, 1988 isolate): identification of the virus as turkey astrovirus 2.

A small round virus (SRV) was isolated in 1988 from droppings of enteritis-affected turkeys in North Carolina and tentatively identified as an enterovirus on the basis of size (18-24 nm in diameter), intracytoplasmic morphogenesis, and a single-stranded RNA genome of approximately 7.5 kb. Additional characterization studies based on antigenic and genomic analyses were done to determine the relationship of this turkey enterovirus-like virus (TELV) to turkey astrovirus 2 (TAstV2), a recently characterized SRV of turkeys. Cross-immunofluorescence studies with TELV- and TAstV2-specific antisera indicated a close antigenic relationship between these viruses. TELV RNA was amplified by reverse transcriptase-polymerase chain reaction (RT-PCR) procedures with oligonucleotide primers specific for TAstV2 polymerase gene (open reading frame [ORF] 1b) and capsid protein gene (ORF 2). Subsequent sequence analyses of these TELV-derived RT-PCR products indicated a high degree of similarity with polymerase gene (98.8%) and capsid gene (96.9%) of TAstV2. These studies definitively identify TELV (North Carolina, 1988 isolate) as TAstV2.