Summary
Sterilized soil (pH 7.7) seeded withC. neoformans was incubated at different temperatures and under various atmospheric conditions during a summer and winter.
Incubated for one year at constant temperatures in atmospheric humidities, the organism survived in greater number and for longer periods of time at 4–6° C. Increased humidity greatly enhanced the survival and proliferation of the organisms incubated at 4–6° C and 20–24° C but had little effect on organisms incubated at 37° C.
Summer temperatures in Oklahoma coupled with direct exposure to the sun were lethal to the organism in 100 % humidity. In the winter months, exposure to sunlight had no effect on the viability ofC. neoformans.
As incubation time in soil increased the thickness of the capsule decreased.Cryptococcus neoformans probably exists in nature in nearly nonencapsulated state. It survives best in alkaline soils, in areas of high humidity, and where the organisms are protected from high temperatures and direct sunlight.
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References
Ajello, L. 1958, Occurrence ofCryptococcus neoformans in soils. Amer. J. Hyg.67: 72–77.
Emmons, C. W. 1955. Saprophytic sources ofCryptococcus neoformans associated with the pigeon (Columba livia). Amer. J. Hyg.62: 227–232.
Emmons, C. W. 1960. Prevalence ofCryptococcus neoformans in pigeon habitats. Publ. Health Repts.75: 362–364.
Ishaq, C. M. 1965. An evaluation of various environmental factors affecting the propagation ofCryptococcus neoformans. Ph. D. Thesis, University of Oklahoma School of Medicine.
Kao, C. J. &Schwarz, J. 1957. The isolation ofCryptococcus neoformans from pigeon nests. Amer. J. clin. Path.27: 652–663.
Kuhn, L. R. 1939. Growth and viability ofCryptococcus hominis at mouse and rabbit body temperatures. Proc. Soc. exp. Biol. Med.41: 573–574.
Mosberg, W. H. &Alvarez De-Choudens J. A., 1951. Torulosis of central nervous system; Effect of changes in pH and temperature on growth of causal organism. Lancet1: 1259–1261.
Muchmore, H. G., Rhoades, E. R., Nix, G. E., Felton, F. G. &Carpenter, R. E. 1963. Occurrence ofCryptococcus neoformans in the environment of three geographically associated cases of Cryptococcal meningitis. New Engl. J. Med.268: 1112–1114.
Ritter, R. C. &Larsh, H. W. 1963. The infection of white mice following an intranasal installation ofCryptococcus neoformans. Amer. J. Hyg.78: 241–246.
Sans, M. D. 1966. Phagocytosis ofCryptococcus neoformans by human leukocytes. M. S. Thesis, University of Oklahoma School of Medicine.
Shields, A. B. &Ajello, L. 1966. Medium for selective isolation ofCryptococcus neoformans. Science151: 208–209.
Silva, M. E. &Paula, L. A. 1963. Isolamento deCryptococcus neoformans de excrementos e ninhos de pombos (Columbia livia) em Salvador, Bahia (Brazil). Rev. Inst. Med. Trop. S. Paulo5: 9–11.
Staib, F. 1961. Vorkommen vonCryptococcus neoformans im Vogelmist. Zbl. Bakt.182: 562–563.
Staib, F. 1963. Zur Widerstandsfähigkeit vonCryptococcus neoformans gegen Austrocknung und hohe Temperaturen. Arch. Microbiol.44: 323–333.
Yamamoto, S., Ishida, K. &Sato, A. 1957. Isolation ofCryptococcus neoformans from pulmonary granuloma of a cat and from pigeon droppings. Jap. J. vet. Sci.19: 179–191.
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This investigation was partially supported by Public Health Service grants AIO5022 and CC-00081, from the National Institute of Health.
This work was done in partial fulfillment for the Ph.D. degree.
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Ishaq, C.M., Bulmer, G.S. & Felton, F.G. An evaluation of various environmental factors affecting the propagation of Cryptococcus neoformans. Mycopathologia et Mycologia Applicata 35, 81–90 (1968). https://doi.org/10.1007/BF02049570
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DOI: https://doi.org/10.1007/BF02049570