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INFECTION OF WHITE SWISS MICE WITH AIRBORNE CRYPTOCOCCUS NEOFORMANS
Abstract:
Smith, C. D. (Communicable Disease Center, Kansas City, Kansas), R. Ritter, H. W. Larsh, and M. L. Furcolow. Infection of white Swiss mice with airborne Cryptococcus neoformans. J. Bacteriol. 87:1364-1368. 1964.-A group of 39 white Swiss male mice were allowed to run 3 days on previously sterilized soil that had been seeded with Cryptococcus neoformans 1 year previously. It was determined that the soil contained an average of 1.6 x 10(6) viable yeast cells per ml. The mice were observed for 24 weeks, at which time the survivors were necropsied. The total mortality rate during this period was 44%; 67% of the mice had positive cultures, including all who had a fatal infection. Two additional experiments were done with the same strain with the use of aerosols produced by a Henderson apparatus. In experiment 1, 39 mice received 11,000 viable cells each; in experiment 2, 40 mice received 14,622 viable cells. Both groups of mice showed similar mortality rates, with a total of 77% dead after 20 weeks in experiment 1, and 80% in experiment 2. All of the mice in experiment 1 had positive cultures, as did 95% of the mice in experiment 2.
Insights
Airborne Cryptococcus neoformans infection in mice led to significant mortality. Most infected mice showed positive cultures, indicating systemic spread of the fungal pathogen.
Area of Science:
- Mycology
- Infectious Diseases
- Animal Models
Background:
- Cryptococcus neoformans is a fungal pathogen known to cause serious infections.
- Understanding transmission routes is crucial for preventing cryptococcosis.
Purpose of the Study:
- To investigate the infectivity of airborne Cryptococcus neoformans in a mouse model.
- To determine the mortality rates and culture positivity following experimental exposure.
Main Methods:
- Mice were exposed to soil contaminated with Cryptococcus neoformans or to aerosols of the fungus.
- Mortality was monitored over several weeks, and survivors were necropsied for culture analysis.
Main Results:
- Exposure to airborne Cryptococcus neoformans resulted in high mortality rates (44% to 80% depending on the experiment).
- A high percentage of mice developed positive cultures (67% to 100%), with all fatal infections showing positive cultures.
Conclusions:
- Airborne Cryptococcus neoformans is highly infectious and can cause significant mortality in mice.
- Fungal cultures confirmed systemic infection in a majority of exposed animals, highlighting the efficacy of this transmission route.
