Detection and molecular characterization of enteric viruses in breeder turkeys

The present study was undertaken to detect and characterize enteric viruses (rotavirus, astrovirus, reovirus, and coronavirus) in breeder poults. Five turkey breeder flocks were selected. Faecal samples were collected from all flocks at 1 week of age and then every other week until the poults reached 9 weeks of age. The faecal samples were pooled in groups of five. Of the 193 pools ("samples") tested by reverse transcriptionpolymerase chain reaction, 47.2%, 30.6%, and 10.4% samples were positive for astrovirus, rotavirus, and reovirus, respectively. No coronavirus was detected in any of the samples. Overall, 118 (61.1%) samples were positive for one or more enteric viruses. Of the 118 samples, 70 (59.3%) were positive for a single virus and 48 (40.7%) for a combination of viruses. Phylogenetic analysis based on the polymerase gene showed that astroviruses clustered into two groups with sequence homology ranging from 85.6 to 100% at the nucleotide level. Based on NSP4 gene sequences, rotaviruses clustered in a group and had 96.3 to 99.9% sequence homology at the nucleotide level. The reoviruses, based on their S4 gene sequences, clustered in a single group with sequence homology of 96.9 to 100%. Differing amino acid sequences of all three viruses may affect the antigenicity and/or pathogenicity of these viruses and may merit further study. The presence of two or three different viruses in combination may affect the dynamics of turkey health and disease.