Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-02T23:20:24.293Z Has data issue: false hasContentIssue false

Comparison of the biological characteristics of two isolates of Neospora caninum

Published online by Cambridge University Press:  01 April 1999

R. ATKINSON
Affiliation:
Molecular Parasitology Unit, Department of Cell and Molecular Biology, University of Technology, Sydney, Westbourne Street, Gore Hill, NSW 2065, Australia
P. A. W. HARPER
Affiliation:
Grafton Agricultural Research and Advisory Station (NSW Agriculture), Grafton, NSW 2460, Australia
C. RYCE
Affiliation:
Molecular Parasitology Unit, Department of Cell and Molecular Biology, University of Technology, Sydney, Westbourne Street, Gore Hill, NSW 2065, Australia
D. A. MORRISON
Affiliation:
Molecular Parasitology Unit, Department of Cell and Molecular Biology, University of Technology, Sydney, Westbourne Street, Gore Hill, NSW 2065, Australia
J. T. ELLIS
Affiliation:
Molecular Parasitology Unit, Department of Cell and Molecular Biology, University of Technology, Sydney, Westbourne Street, Gore Hill, NSW 2065, Australia

Abstract

This study compared the biological and genetic properties of a bovine (NC-SweB1) and a canine (NC-Liverpool) isolate of Neospora caninum. A mouse model for CNS infection demonstrated marked differences in pathogenicity between the isolates. NC-Liverpool induced severe clinical signs of neosporosis in 57/58 mice including discoordinated movement, hindlimb paralysis and coat ruffling with severe weight loss. In contrast NC-SweB1 induced similar but less severe symptoms in a much smaller proportion of mice over the same time-period. Statistically significant differences were observed between the isolates in the response (mean weight loss) of mice through time to the different doses inoculated. Histopathological effects on brain tissue reflected the isolate-based differences described above. NC-Liverpool infection resulted in intense inflammatory infiltrates and highly necrotic lesions whereas NC-SweB1 induced a milder meningoencephalitis. Passage in cell-culture over a period of 14 months did not affect the pathogenicity of NC-Liverpool. Immunoblots showed that antibodies to N. caninum appeared earlier in mice inoculated with NC-Liverpool than with NC-SweB1. Finally, RAPD–PCR analysis of NC-Liverpool DNA generated profiles distinct from that observed with DNA from NC-SweB1 or Toxoplasma gondii. In summary this study provides evidence for significant biological and genetic differences between 2 isolates of N. caninum.

Type
Research Article
Copyright
© 1999 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)