2004 Fiscal Year Final Research Report Summary
Origin and generation of verogenic Newcastle disease viruses
| Project/Area Number |
14360178
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Basic veterinary science/Basic zootechnical science
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| Research Institution | Tottori University |
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Principal Investigator |
ITO Toshihiro National University Corporation Tottori University, Faculty of Agriculture, Professor, 農学部, 教授 (00176348)
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| Co-Investigator(Kenkyū-buntansha) |
ITO Hiroshi National University Corporation Tottori University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (10332777)
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| Project Period (FY) |
2002 – 2004
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| Keywords | Newcastle disease / poultry / waterfowl / pathogenicity / origin / NDV / chicken / cleavage |
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| Research Abstract |
A benign Newcastle disease virus(NDV) recently became highly virulent during replication in domestic chickens. It is still unclear whether NDVs circulating among wild waterfowl also have the potential to become highly pathogenic (velogenic) in chickens. To demonstrate experimentally the generation of velogenic NDV from a nonpathogenic waterfowl isolate, we passaged an avirulent goose isolate in chickens. After nine consecutive passages by air-sac inoculation, followed by five passages in chick brain, the virus became highly virulent in chickens, producing a 100% mortality rate, and demonstrating typical velogenic properties in pathogenicity tests. Sequence analysis at the fusion protein cleavage site showed that the original isolate contained the typical avirulent type sequence, E-R-Q-E-R/L, which progressed incrementally to a typical virulent type, K-R-Q-K-R/F, during repeated passage in chickens. These results demonstrate that avirulent viruses, maintained in wild waterfowl in nature and bearing the consensus avirulent type sequence, have the potential to become velogenic after transmission to and circulation in chicken populations. The results also suggest that chickens provide a mechanism for the selection of virulent viruses from an avirulent background.
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