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A model of coccidioidal meningoencephalitis and cerebrospinal vasculitis in the rabbit
P L Williams1, R A Sobel, K N Sorensen
1Department of Medicine, Kaweah Delta Health Care District, Visalia, California, USA.
Abstract:
Coccidiodal meningitis is a devastating complication of disseminated coccidioidomycosis. An animal model of this infection could enhance understanding of the pathogenesis of the disease and lead to improvements in therapy. A rabbit model of central nervous system infection simulating human disease was established using a blind cisternal tap technique to inoculate 4 x 10(3)-1 x 10(6) arthroconidia of Coccidioides immitis into the cisterna magna. Systemic, neurologic, and histopathologic findings of meningitis were observed in all rabbits, but an inoculum of 2 x 10(4) arthroconidia produced a chronic illness in which meningeal endarteritis obliterans was consistently observed. Serial sampling of cerebrospinal fluid demonstrated an inflammatory response. Growth of C. immitis was demonstrated by quantitative fungal culture from brains and proximal spinal cords.
Insights
Researchers developed a rabbit model for coccidiodal meningitis, a severe complication of coccidioidomycosis. This model helps study disease progression and test new therapies for fungal meningitis.
Area of Science:
- Mycology
- Infectious Diseases
- Neurology
Background:
- Coccidioidomycosis is a fungal infection endemic to the southwestern United States.
- Disseminated coccidioidomycosis can lead to coccidiodal meningitis, a serious central nervous system complication.
- A robust animal model is needed to study coccidiodal meningitis pathogenesis and evaluate therapeutic strategies.
Purpose of the Study:
- To establish and characterize a rabbit model of coccidiodal meningitis.
- To simulate human central nervous system infection caused by Coccidioides immitis.
- To investigate the pathological findings and host response in a controlled experimental setting.
Main Methods:
- A rabbit model was created using a blind cisternal tap technique.
- Arthroconidia of Coccidioides immitis were inoculated into the cisterna magna at varying concentrations (4 x 10(3) to 1 x 10(6)).
- Systemic, neurologic, and histopathologic assessments were performed, alongside cerebrospinal fluid analysis and fungal cultures.
Main Results:
- All inoculated rabbits exhibited systemic, neurologic, and histopathologic signs of meningitis.
- An inoculum of 2 x 10(4) arthroconidia consistently induced a chronic illness characterized by meningeal endarteritis obliterans.
- Cerebrospinal fluid analysis revealed an inflammatory response, and Coccidioides immitis was cultured from brain and spinal cord tissues.
Conclusions:
- The developed rabbit model effectively simulates coccidiodal meningitis, offering a platform for further research.
- The model demonstrates the potential for chronic disease development and specific pathological findings like meningeal endarteritis obliterans.
- This model provides a valuable tool for understanding coccidiodal meningitis pathogenesis and for preclinical testing of antifungal therapies.