The possible role of uric acid in the ecology of Histoplasma capsulatum
Tóm tắt
The results of this study indicate thatHistoplasma capsulatum in its saprophytic form is able to utilize the major nitrogenous constituent of avian manure as a nitrogen source. In addition, the enzymes responsible for the pathway of uric acid degradation to inorganic nitrogen have been demonstrated in cell-free systems. These enzymes include uricase, allantoinase, allantoicase, and urease. The uricase ofHistoplasma appears to be a cell wall or cell membrane-associated enzyme, while the other enzymes were located in the soluble portion of cell-free extracts. Cell-free extracts ofCryptococcus neoformans are actively uricolytic. It is suggested that this ability ofH. capsulatum hyphae to utilize uric acid and related compounds as growth substrates may in part explain the indisputable ecologic association of this pathogenic fungus with avian and possibly chiropteran-associated soils and habitats in those areas endemic for histoplasmosis.
Tài liệu tham khảo
Ajello, L. 1967. Comparative ecology of respiratory mycotic disease agents. Bact. Rev.31: 6–24.
Anderson, K. L. &Marcus, S. 1967. Sporulation characteristics ofHistoplasma capsulatum; Bact. Proc. pp. 68.
Archibald, R. M. 1945. Colorimetric determination of urea, J. biol. Chem.157: 507–518.
Bare, L., Wiseman, R. &Ruchman, I. 1966. Uricolysis byEscherichia ssp., Appl. Microbiol.14: 474.
Brown, G. W. 1964. Allantoinase assay procedure, Amer. Zool.4: 310–311.
Brown, G. W., James, J., Henderson, R. J., Thomas, W. N., Robinson, R., Thompson, A. L., Brown, E. &Brown, S. G. 1966. Uricolytic enzymes in liver of the dipnoanProtopterus aethiopicus; Science.153: 1653–1654.
Cochrane, V. 1958. Physiology of fungi, John Wiley and Sons, Inc., New York.
Emmons, C. W. 1955. Saprophytic sources ofCryptococcus neoformans associated with the pigeon (Columba livia), Amer. J. Hyg.62: 227–232.
Furcolow, M. L. 1960. Epidemiology of histoplasmosis, in Histoplasmosis, ed. byH. Sweany. C. C. Thomas, Publisher. Springfield, Ill.
Howell, R. R. &Wyngaarden, J. B. 1960. On the mechanism of peroxidation of uric acid by hemoproteins, J. biol. Chem.235: 3544–3550.
Hutchinson, G. 1950. The biogeochemistry of vertebrate excretion, Bull. Amer. Museum Nat. Hist.96: 71–90.
Kalckar, H. M. 1947. Differential spectrophotometry of purine compounds by means of specific enzymes. J. biol. Chem.167: 429–443.
Klite, P. D. &Diercks, F. H. 1965.Histoplasma capsulatum in fecal contents and organs of bats in the Canal Zone, Amer. J. trop. Med. Hyg.14: 433–439.
Lowry, O. H., Rosebrough, N. J., Farr, A. L. &Randall, R. J. 1951. Protein measurement with the Folin phenol reagent, J. biol. Chem.193: 265–275.
Maruyama, Y. &Alexander, M. 1962. Localization of enzymes in the mycelium and microconidia ofFusarium oxysporum, J. Bact.84: 307–312.
McVeigh, I. &Morton, K. 1965. Nutritional studies ofHistoplasma capsulatum, Mycopath. Mycol. Appl.25: 294–308.
Pine, L. 1960. Morphological and physiological characteristics ofHistoplasma capsulatum. in Histoplasmosis, ed. byH. Sweany, C. C. Thomas, Publisher, Springfield, Ill.
Schulman, M. P. 1961. Purines and pyrimidines. in Metabolic pathways. ed. byD. M. Greenberg. Academic Press, New York.
Smith, C. D. &Furcolow, M. L. 1964. The demonstration of growth stimulating substances forHistoplasma capsulatum andBlastomyces dermatitidis in infusions of Starling's (Sturnis vulgaris) manure, Mycopath. Mycol. Appl.22: 73–80.
Staib, F. 1962. Vogelkot, ein Nährsubstrat für die GattungCryptococcus, Zbl. Bakt. I. Abt. Orig.186: 233–247.
Stotzky, G. &Post, A. H. 1967. Soil mineralogy as possible factor in geographic distribution ofHistoplasma capsulatum, Canad. J. Bact.13: 1–7.
Taka, E. E. M., Storck-Krieg, L. &Franke, W. 1955. Purinoxydierende Fermente aus Schimmelpilzen. IV. Über die Xanthindehydrase der Schimmelpilze, Arch. Mikrobiol.23: 67–78.
Taylor, J. J. 1962. Demonstration and possible significance of uricase in human pathogenic fungi, Nature. Lond.194: 403–404.
Vanbreuseghem, R. &Eugene, J. 1958. Culture d'Histoplasma capsulatum et d'Histoplasma duboisii sur un milieu à base de terre et de matières fécales provenant de divers animaux, C. R. Soc. Bio.152: 1602–1605.
Vitols, E. &Linnane, A. W. 1961. Studies on the oxidative metabolism ofSaccharomyces cerevisiae. II. Morphology and oxidative phosphorylation capacity of mitochondria and derived particles from Baker's yeast, J. Biophys. Biochem. Cytol.9: 701–710.