| Autor: |
Simmons, Cameron P., Dunstan, Sarah J., Tachedjian, Mary, Krywult, Jolanta, Hodgson, Adrian L. M., Strugnell, Richard A. |
| Zdroj: |
Infection and Immunity; February 1998, Vol. 66 Issue: 2 p474-479, 6p |
| Abstrakt: |
ABSTRACTCorynebacterium pseudotuberculosis, a gram-positive facultative intracellular bacterial pathogen, is the etiological agent of the economically important disease caseous lymphadenitis (CLA) in both sheep and goats. Attenuated mutants of C. pseudotuberculosishave the potential to act as novel vaccines against CLA and as veterinary vaccine vectors. In this report, we have assessed the virulence of both aroQand pldmutants of C. pseudotuberculosisin sheep and concurrently their capacity to act as vaccines against homologous challenge. The results suggest that aroQmutants of C. pseudotuberculosisare attenuated with regard to both lymph node persistence and vaccination site reactogenicity. Immunologically,aroQmutants failed to elicit detectable specific gamma interferon (IFN-γ)-secreting lymphocytes and induced low levels of antibodies to C. pseudotuberculosisculture supernatant antigens. Following subcutaneous vaccination, the immune responses induced by aroQmutants did not protect sheep from infection with the wild-type strain but did appear to reduce the clinical severity of disease resulting from challenge. Conversely, an attenuated C. pseudotuberculosisstrain expressing an enzymatically inactive phospholipase D exotoxin, when used as a vaccine, elicited a protective immune response. Protection appeared to correlate with in vivo persistence of the vaccine strain, the induction of IFN-γ-secreting lymphocytes, and relatively high levels of antibodies to culture supernatant antigens. The results suggest thataroQmutants of C. pseudotuberculosismay be overly attenuated for use as a CLA vaccines or as vaccine vectors. |
| Databáze: |
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