| Autor: |
J F, Markham, C J, Morrow, P C, Scott, K G, Whithear |
| Rok vydání: |
1999 |
| Předmět: |
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| Zdroj: |
Avian diseases. 42(4) |
| ISSN: |
0005-2086 |
| Popis: |
A temperature-sensitive (ts+) clone derived from the Australian Mycoplasma synoviae (MS) field isolate 86079/7NS was produced by chemical mutagenesis with N-methyl-N'-nitro-N-nitrosoguanidine and assessed for safety as a live vaccine. This clone, designated MS-H, was assessed for pathogenicity in three different models with air sac lesions as the criterion. No air sac lesions were observed when MS-H was administered to specific-pathogen-free hybrid white leghorn (HWL) chickens by eyedrop at 10 times the normal dose or directly into the thoracic air sacs or as an aerosol administered to specific-pathogen-free Webster white leghorn chickens with concurrent intratracheal T-strain infectious bronchitis virus (IBV). MS-H did not revert to virulence or lose the ts+ phenotype when passaged through five in vivo and 10 in vitro passages. No adverse effects were seen when HWL chickens were vaccinated concurrently with MS-H and combinations of Mycoplasma gallisepticum ts-11 vaccine, IBV vaccine, and infectious laryngotracheitis virus vaccine. Lateral transmission of MS-H was found to occur when vaccinated HWL chickens were mixed with unvaccinated chickens 2 wk after vaccination. At 1 wk after mixing, one out of two unvaccinated chickens had seroconverted to MS and was culture positive for MS. At 2 wk after mixing, both contact chickens were positive for MS by culture and serology. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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