Porcine Torque teno virus: Determination of viral genomic loads by genogroup-specific multiplex rt-PCR, detection of frequent multiple infections with genogroups 1 or 2, and establishment of viral full-length sequences
| Autor: | Christoph Keller, Wiebke Schulze Esking, Andreas Gallei, Volker Ohlinger, Stefan Pesch |
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| Rok vydání: | 2010 |
| Předmět: |
Torque teno virus
medicine.medical_specialty Genotype Swine Molecular Sequence Data Genome Viral Biology Microbiology Genome Virus law.invention law Germany Molecular genetics Prevalence medicine Animals Multiplex Phylogeny Polymerase chain reaction Swine Diseases Base Sequence General Veterinary Reverse Transcriptase Polymerase Chain Reaction General Medicine Virology DNA Virus Infections Real-time polymerase chain reaction DNA Viral |
| Zdroj: | Veterinary Microbiology. 143:202-212 |
| ISSN: | 0378-1135 |
| Popis: | Torque teno virus (TTV) is a non-enveloped virus with a circular, single-stranded DNA genome. TTV is currently classified in the unassigned genus Anellovirus, and distinct TTVs of tentative species-status infect a wide range of vertebrates. In domestic pigs and wild boars, porcine TTV occurs in two genogroups, TTV1 and TTV2, which are currently detected using only conventional PCR assays. To allow high-throughput testing, the present study describes development of a multiplex real-time (rt)-PCR assay for efficient simultaneous detection of TTV1 and TTV2. To demonstrate usefulness of this rt-PCR assay for large-scale testing, 203 serum samples from domestic pigs were screened for TTV infection. The detected rates of single TTV1, single TTV2, and double TTV1/TTV2 infections were 32, 17, and 32% and represent the first report on the occurrence of porcine TTV in Germany. In addition, 100 wild boar lung samples were tested that confirmed high prevalences of TTV infection. Moreover, establishment of genogroup-specific rt-PCR standards allowed the determination of mean viral genomic loads in sera from TTV-infected swine to about 10(4.5)/ml, respectively. To verify the specificity of the rt-PCR assay, conventional PCR assays that amplify genogroup-specific, size-distinguishable products from the TTV untranslated regions were designed. In total, 50 clones derived from 24 PCR products obtained from 19 TTV1 and TTV2 single- or double-infected animals were sequenced. Phylogenetic analyses of these sequences demonstrated the frequent occurrence of multiple infections with distinct porcine TTVs of the same genogroup. Moreover, two porcine TTV full-length sequences were established, one for each genogroup. |
| Databáze: | OpenAIRE |
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