ARS | Publication request: Molecular virus screening to detect novel viruses from turkey flocks affected by Poult Enteritis Mortality Syndrome

Submitted to: World Veterinary Poultry Association
Publication Type: Abstract Only
Publication Acceptance Date: May 15, 2007
Publication Date: October 15, 2007
Citation: Zsak, L., Woolcock, P.R. 2007. Molecular virus screening to detect novel viruses from turkey flocks affected by Poult Enteritis Mortality Syndrome[abstract]. 15th Congress of the World Veterinary Poultry Association. Paper No. 1 (Sept 15, Session A).

Technical Abstract: Poult Enteritis Mortality Syndrome (PEMS) is an economically important, infectious enteric disease of young turkeys. The disease is characterized by decreased weight gain, increased morbidity and mortality, and increased production costs due to poor feed conversions. PEMS is considered to be a multifactorial disease and many different viruses have been isolated from the intestinal contents of affected poultry flocks including avian reoviruses, rotaviruses, astroviruses (1). Recent pathogenesis studies revealed that reoviruses may contribute to poult enteritis as predisposing agents (2). Because some of these viruses are also present in apparently healthy flocks their function in inducing PEMS is presently not completely understood (3). It is reasonable to speculate that other, yet unidentified viruses may also play important role in the etiology of PEMS. Here, we report the application of a molecular screening method that was designed to detect novel viruses from intestinal samples of turkeys exhibiting PEMS. Intestinal homogenates were pooled, clarified by low-speed centrifugation, filtered through a 0.45-um-pore-size filter and pelleted by ultracentrifugation at 37,000 x rpm for 3 hours. Following DNase treatment the particle-associated nucleic acid was extracted, the DNA was randomly amplified using random hexamer oligonucleotides, and PCR products were cloned and sequenced. Sequences obtained were analyzed for homologies to nucleotide and amino acid sequences in the GenBank database by using the BLASTn and BLASTx searches, respectively. After the vector sequences and low-quality sequences were discarded, 146 clones remained to study. In total, 19% of clones analyzed showed significant similarity to viral sequences at the amino acid level. The deduced amino acid sequences significantly matched members of the Adenoviridae, Poxviridae, Herpesviridae and Parvoviridae families. Although the applied random PCR methodology would allow detecting only viral genomic fragments our results strongly indicate the presence of potential novel viruses in the turkey enteric samples.