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. 1988 Mar;56(3):711–713. doi: 10.1128/iai.56.3.711-713.1988

Inhibition by estrogens of conidium-to-yeast conversion in the fungus Paracoccidioides brasiliensis.

M E Salazar 1, A Restrepo 1, D A Stevens 1
PMCID: PMC259352  PMID: 3343055

Abstract

Conidia produced by Paracoccidioides brasiliensis are inhibited by mammalian estrogens in their in vitro conversion into yeast-form cells. This was demonstrated with four different isolates. In these experiments, conversion was reduced to 10.7 and 34.4% of the control values by 17-beta-estradiol at 10(-6) and 10(-8) M, respectively. At the same concentrations, the synthetic estrogen diethylstilbestrol was slightly less inhibitory. In contrast, other sex hormones and analogs, i.e., testosterone, 17-alpha-estradiol, tamoxifen, and hydroxytamoxifen, had no effect on conidium-to-yeast conversion. Previous studies have shown that estrogens similarly inhibit mycelium-to-yeast-form transition in P. brasiliensis. Conidia, and not mycelial fragments, are believed to be the natural infectious propagules. These findings with conidia support the hypothesis that estrogens, affecting the initial host-parasite interactions by suppressing conversion to the parasitic form of the organism, are, at least in part, responsible for the greater resistance of females to paracoccidioidomycosis.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bustamante-Simon B., McEwen J. G., Tabares A. M., Arango M., Restrepo-Moreno A. Characteristics of the conidia produced by the mycelial form of Paracoccidioides brasiliensis. Sabouraudia. 1985 Dec;23(6):407–414. doi: 10.1080/00362178585380601. [DOI] [PubMed] [Google Scholar]
  2. Loose D. S., Stover E. P., Restrepo A., Stevens D. A., Feldman D. Estradiol binds to a receptor-like cytosol binding protein and initiates a biological response in Paracoccidioides brasiliensis. Proc Natl Acad Sci U S A. 1983 Dec;80(24):7659–7663. doi: 10.1073/pnas.80.24.7659. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. McEwen J. G., Bedoya V., Patiño M. M., Salazar M. E., Restrepo A. Experimental murine paracoccidiodomycosis induced by the inhalation of conidia. J Med Vet Mycol. 1987 Jun;25(3):165–175. doi: 10.1080/02681218780000231. [DOI] [PubMed] [Google Scholar]
  4. Restrepo A., Cano L. E., de Bedout C., Brummer E., Stevens D. A. Comparison of various techniques for determining viability of Paracoccidioides brasiliensis yeast-form cells. J Clin Microbiol. 1982 Jul;16(1):209–211. doi: 10.1128/jcm.16.1.209-211.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Restrepo A., Jiménez B. E. Growth of Paracoccidioides brasiliensis yeast phase in a chemically defined culture medium. J Clin Microbiol. 1980 Aug;12(2):279–281. doi: 10.1128/jcm.12.2.279-281.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Restrepo A., Salazar M. E., Cano L. E., Patiño M. M. A technique to collect and dislodge conidia produced by Paracoccidioides brasiliensis mycelial form. J Med Vet Mycol. 1986 Jun;24(3):247–250. [PubMed] [Google Scholar]
  7. Restrepo A., Salazar M. E., Cano L. E., Stover E. P., Feldman D., Stevens D. A. Estrogens inhibit mycelium-to-yeast transformation in the fungus Paracoccidioides brasiliensis: implications for resistance of females to paracoccidioidomycosis. Infect Immun. 1984 Nov;46(2):346–353. doi: 10.1128/iai.46.2.346-353.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]

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