RRC ID 31917
Author Kurita N, Brummer E, Yoshida S, Nishimura K, Miyaji M.
Title Antifungal activity of murine polymorphonuclear neutrophils against Histoplasma capsulatum.
Journal J. Med. Vet. Mycol.
Abstract Murine polymorphonuclear neutrophils (PMN) were examined for fungicidal and fungistatic activity against yeast cells of Histoplasma capsulatum. In a 16-h limiting dilution assay (LDA) (constant number of PMN versus decreasing numbers of yeast cells) where PMN to yeast cell ratios were high (0.4-1.5 x 10(5):1), murine PMN exhibited a limited fungicidal effect on H. capsulatum as measured by sterilization of cultures containing one to four yeast cells. On the other hand, inoculum colony forming units (c.f.u.) of H. capsulatum were not reduced by PMN in short-term (2 h) assays (PMN to yeast cell ratio, 500:1) even though H. capsulatum stimulated a brisk oxidative burst in PMN. In the same assays 84% of Candida albicans cells were killed. These findings indicate that H. capsulatum was resistant to killing by products of the oxidative burst generated by PMN and that it was slightly sensitive to PMN in 16-h LDA assays where a different microbicidal mechanism may be operative. In long-term co-culture assays, where the PMN to yeast cell ratio was 500:1, PMN consistently inhibited the replication of H. capsulatum after 24, 48, or 72 h of incubation. Inoculum c.f.u. failed to increase significantly in co-cultures, whereas in culture medium alone c.f.u. increased several-fold in 72 h. Based on these novel findings, we speculate that PMN might play a role in resistance to H. capsulatum due to their strong fungistatic activity and to a lesser extent their limited fungicidal action.
Volume 29(3)
Pages 133-43
Published 1991
PMID 1890560
MeSH Animals Candida albicans / growth & development Candida albicans / immunology* Cells, Cultured Histoplasma / growth & development Histoplasma / immunology* Histoplasma / isolation & purification Hydrogen Peroxide / pharmacology Luminescent Measurements Male Mice Mice, Inbred BALB C NADP Neutrophils / immunology* Neutrophils / metabolism Peritoneal Lavage Phagocytosis / immunology*
Times Cited 16
Pathogenic microorganisms IFM 41329