1887

Abstract

produces large amounts of the acyclic hexitol mannitol in culture and infected animals, but the functional and pathogenic significance of mannitol production by this fungus is not known. We exposed H99 (Cn H99) to UV irradiation (1 × LD) and screened survivors for mannitol production. A mutant, Cn MLP (Mannitol Low Producer), synthesized less mannitol from glucose (2.7 vs 8.2 nmol per 10 cells min at 37 °) and contained less intracellular mannitol (1 vs 11 μmol per 10 cells at 37 °) than did Cn H99. Cn MLP and Cn H99 were similar with respect to carbon assimilation patterns, rates of glucose consumption, growth rates at 30 °, urease and phenoloxidase activities, morphology, capsule formation, mating type, electrophoretic karyotype, rapid amplification of polymorphic DNA (RAPD) patterns and antifungal susceptibility. However, Cn MLP was more susceptible than was Cn H99 to growth inhibition and killing by heat and high NaCl concentrations. Also, the LD values in mice injected intravenously were 3.7 × 10 c.f.u. for Cn MLP compared to 6.9 × 10 c.f.u. for Cn H99. Moreover, 500 c.f.u. Cn H99 intravenously killed 12 of 12 mice by 60 d, whereas all mice given the same inoculum of Cn MLP survived. Classical genetic studies were undertaken to determine if these differences were due to a single mutation, but the basidiospores were nonviable. These results suggest that the abilities of to produce and accumulate mannitol may influence its tolerance to heat and osmotic stresses and its pathogenicity in mice.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-142-4-937
1996-04-01
2021-05-06
Loading full text...

Full text loading...

/deliver/fulltext/micro/142/4/mic-142-4-937.html?itemId=/content/journal/micro/10.1099/00221287-142-4-937&mimeType=html&fmt=ahah

References

  1. Albertyn A., Hohmann S., Thevelein J.M., Prior B.A. GPD1, which encodes glycerol-3-phosphate dehydrogenase, is essential for growth under osmotic stress in Saccharomyces cerevisiae, and its expression is regulated by the high-osmolarity glycerol response pathway. Mol Cell Biol 1994; 14:4135–4144
    [Google Scholar]
  2. Campbell I. Standard media for cultivation of yeasts. In Yeast 1988 Edited by Campbell I., Buffus J.H. Oxford: IRL Press; a Practical Approach, pp 277–279
    [Google Scholar]
  3. Chuck M.T., Sande M.A. Infections with Cryptococcus neoformans in acquired immunodeficiency syndrome. N Engl J Med 1989; 321:794–799
    [Google Scholar]
  4. Cushion M.T., Kaselis M., Stringer S.L., Stringer J.R. Genetic stability and diversity of Pneumocystis carinii infecting rat colonies. Infect Immun 1993; 61:4801–4813
    [Google Scholar]
  5. Edgley M., Brown A.D. Yeast water relations: physiological changes induced by solute stress in Saccharomyces cerevisiae and Saccharomyces rouxii. J Gen Microbiol 1983; 129:3453–3463
    [Google Scholar]
  6. Jennings D.H. Polyol metabolism in fungi. Adv Microb Physiol 1984; 25:149–193
    [Google Scholar]
  7. Kwon-Chung K.J., Bennett J.E. Cryptococcosis. In Medical Mycology 1992 Philadelphia: Lea & Febiger; pp 397–446
    [Google Scholar]
  8. Larsson C., Gustafsson L. The role of physiological state in osmotolerance of the salt-tolerant yeast Debaryomyces hansenii. Can J Microbiol 1993; 39:603–609
    [Google Scholar]
  9. Larsson K., Anseil R., Eriksson P., Adler L. A gene encoding sn-glycerol 3-phosphate dehydrogenase (NAD+) complements an osmosensitive mutant of Saccharomyces cerevisiae. Mol Microbiol 1993; 10:1101–1111
    [Google Scholar]
  10. Levitz S.M. The ecology of Cryptococcus neoformans and the epidemiology of cryptococcosis. Rev Infect Dis 1991; 13:1163–1169
    [Google Scholar]
  11. Lewis J.G., Learmonth R.P., Watson K. Induction of heat, freezing and salt tolerance by heat and salt shock in Saccharomyces cerevisiae. Microbiol 1995; 141:687–694
    [Google Scholar]
  12. Mager W.M., Varela J.C.S. Osmostress response of the yeast Saccharomyces. Mol Microbiol 1993; 10:253–268
    [Google Scholar]
  13. Moore T.D.E., Edman J.E. The alpha-mating type locus of Cryptococcus neoformans contains a peptide pheromone gene. Mol Cell Biol 1993; 13:1962–1970
    [Google Scholar]
  14. Niehaus W.G., Flynn T. Regulation of mannitol biosynthesis and degradation by Cryptococcus neoformans. J Bacteriol 1994; 176:651–655
    [Google Scholar]
  15. Niehaus W.G., Wong B., Skinner T.L. A cryptic gene encodes mannitol dehydrogenase in Saccharomyces cerevisiae. FASEB J 1994; 8:444 (abstract)
    [Google Scholar]
  16. Perfect J.R., Selwyn D.R., Lang M.B., Durack D.T. Chronic cryptococcal meningitis: a new experimental model in rabbits. Am J Pathol 1980; 101:177–184
    [Google Scholar]
  17. Reed L.V., Muench H. A simple method of estimating fifty percent end points. Am J Hyg 1938; 27:493–497
    [Google Scholar]
  18. Trollmo C., Andre L., Blomberg A., Adler A. Physiological overlap between osmotolerance and thermotolerance in Saccharomyces cerevisiae. FEMS Microbiol Lett 1988; 56:321–326
    [Google Scholar]
  19. Wang H., T., Rahaim P., Robbins P., Yocum R.R. Cloning, sequencing and disruption of the Saccharomyces diastaticus DARI gene encoding a glycerol-3-phosphate dehydrogenase. I Bacteriol 1994; 176:7091–7095
    [Google Scholar]
  20. Welsh J., McClelland M. Fingerprinting genomes using PCR with arbitrary primers. Nucleic Acids Rix 1990; 18:7213–7218
    [Google Scholar]
  21. Wong B., Perfect J.R., Breggs S., Wright K.A. Production of hexitol D-mannitol by Cryptococcus neoformans in vitro and in rabbits with experimental meningitis. Infect Immun 1990; 58:1664–1670
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-142-4-937
Loading
/content/journal/micro/10.1099/00221287-142-4-937
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error