Submitted to: Proceedings of Southern Conference on Avian Diseases
Publication Type: Abstract Only
Publication Acceptance Date: December 1, 2004
Publication Date: January 15, 2005
Citation: Pantin Jackwood, M.J., Spackman, E. 2005. Sequence analysis of turkey astroviruses isolated from healthy and sick birds [abstract]. Southern Conference on Avian Diseases. p.22. Technical Abstract: The objective of this study was to determine the genetic variability of Astroviruses in Turkeys. Intestinal and fecal samples from turkey flocks from North Carolina and Virginia ranging in age from 1 to 10 weeks old were examined for the presence of Turkey Astrovirus (TAstV) by real time RT-PCR. TAstV was found in samples collected from flocks with poult enteritis and stunting as well as from healthy flocks. Segments of the polymerase and capsid genes of TAstV were amplified by RT-PCR, cloned, and sequenced. Sequences were compared with the published TAstV sequence (TAstV-2, Koci et al. 2000). The capsid gene nucleotide sequences of the TAstV isolates studied showed between 80% and 96% similarity with the corresponding region of TAstV-2. The deduced amino acid sequences showed a two amino acid deletion in half of the isolates. The TAstV isolates studied formed two well-defined groups, with isolates from healthy flocks clustered in one group and isolates from flocks with poult enteritis and stunting divided between both groups. Sequence analysis of the polymerase gene showed 95 to 98% similarity between the isolates studied but had only an 85% similarity with TAstV-2. The results indicate that there is significant genetic variation between TAstV isolates suggesting that more than one serotype of the virus could be present in the field.