The influence of antifungal antibiotics on some determinants of virulence inCandida albicans andCryptococcus neoformans cells

Borowski, J; Jakoniuk, P; Jablońska, W; Jakubicz, W; Szpak, Andrzej

doi:10.1007/bf01923696

Cited by 3 publications

(2 citation statements)

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“…The C. neoformans capsule is antiphagocytic (31) and confers a large negative charge on the cell (33,47). An inverse association between capsule size and cell phagocytosis has been documented for several cryptococcal strains (1,19,26,53,60). Furthermore, poorly encapsulated and acapsular cells are rapidly phagocytosed and are nonpathogenic (3,7,22,34).…”

Section: Discussionmentioning

confidence: 99%

“…Two previous studies in the literature are relevant to the findings reported here. In 1974, Borowski et al (1) reported that growth of C. neoformans in the presence of low concentrations of AmB could reduce the size of the capsule and promote serum-mediated phagocytosis by murine macrophages. To our knowledge, that report was never followed up by further studies.…”

Section: Discussionmentioning

confidence: 99%

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Amphotericin B and Fluconazole Affect Cellular Charge, Macrophage Phagocytosis, and Cellular Morphology ofCryptococcus neoformansat Subinhibitory Concentrations

Nosanchuk¹,

Cleare

Franzot

et al. 1999

Antimicrob Agents Chemother

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Amphotericin B (AmB) and fluconazole (FLU) are the major antifungal drugs used in the treatment of cryptococcosis. Both drugs are believed to exert their antifungal effects through actions on cell membrane sterols. In this study we investigated whether AmB and FLU had other, more subtle effects on C. neoformans that could contribute to their therapeutic efficacy. C. neoformans cells were grown in media with subinhibitory concentrations of either AmB or FLU and analyzed for cellular charge, phagocytosis by macrophages with antibody and complement opsonins, appearance by scanning electron and light microscopies, and release of the capsular polysaccharide glucuronoxylomannan into the culture medium. Growth in the presence of either AmB or FLU resulted in major reductions in cellular charge, as measured by determination of the zeta potential. Phagocytosis studies demonstrated that exposure of C. neoformans to subinhibitory concentrations of AmB or FLU enhanced phagocytosis by macrophages. Scanning electron microscopy revealed that a large proportion of cells had an altered capsular appearance. Cells grown in medium with either AmB or FLU were smaller and released more glucuronoxylomannan into the culture medium than cells grown without antibiotics. The results suggest additional mechanisms of action for AmB and FLU that may be operative in body compartments where drug levels do not achieve the MICs. Furthermore, the results suggest mechanisms by which AmB and FLU can cooperate with humoral and cellular immune defense systems in controlling C. neoformansinfections.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Amphotericin B and Fluconazole Affect Cellular Charge, Macrophage Phagocytosis, and Cellular Morphology ofCryptococcus neoformansat Subinhibitory Concentrations

Nosanchuk¹,

Cleare

Franzot

et al. 1999

Antimicrob Agents Chemother

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Post‐antifungal effect of polyene, azole and DNA‐analogue agents against oral Candida albicans and Candida tropicalis isolates in HIV disease

Anil

Ellepola

Samaranayake

2001

J Oral Pathology Medicine

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Oropharyngeal candidiasis (OPC) is the most frequent AIDS-associated opportunistic infection, as up to 90% of HIV-infected individuals suffer at least one episode during the course of their disease. Various in vivo and in vitro procedures have been used to assess the effectiveness of antifungal agents used in HIV infection. In the present study, we evaluated in vitro the minimum inhibitory concentration (MIC) and the post-antifungal effect (PAFE) of two polyenes, two azoles and one DNA-analogue against 10 oral isolates of Candida albicans and 10 of Candida tropicalis, all from HIV-infected individuals, in order to obtain basic data on the pharmacodynamics of these drugs. One-hour exposure to twice the MIC of all the drugs, except fluconazole, elicited a consistently high PAFE in both Candida species. Furthermore, the PAFE elicited by the antifungals (except fluconazole) was significantly prolonged for C. tropicalis compared with C. albicans. This speedy recovery of C. albicans isolates exposed to transient low concentrations of antifungals appeared to reflect its virulence compared with lesser potent species, such as C. tropicalis. Taken together, the current data, while confirming the existence of PAFE in a non-albicans species of Candida, also provide further clues for the recalcitrance of C. albicans species in the face of antifungal therapy for oropharyngeal candidiasis.

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Morphogenesis in Candida Albicans

Odds

Kerridge

1985

CRC Critical Reviews in Microbiology

215

140

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This review will survey environmental controls on the morphology of Candida albicans, describe the cellular and ultrastructural events associated with morphological transitions in this fungus, and attempt to relate biochemical phenomena that have been reported to be associated with dimorphic change to C. albicans cell biology. The synthesis of the cell wall of C. albicans and its control remain largely undiscovered, but it is clear that the cell wall is the principal component involved in shape determination. Possible models for C. albicans dimorphism will be critically reviewed.

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The influence of antifungal antibiotics on some determinants of virulence inCandida albicans andCryptococcus neoformans cells

Cited by 3 publications

References 7 publications

Amphotericin B and Fluconazole Affect Cellular Charge, Macrophage Phagocytosis, and Cellular Morphology ofCryptococcus neoformansat Subinhibitory Concentrations

Amphotericin B and Fluconazole Affect Cellular Charge, Macrophage Phagocytosis, and Cellular Morphology ofCryptococcus neoformansat Subinhibitory Concentrations

Post‐antifungal effect of polyene, azole and DNA‐analogue agents against oral Candida albicans and Candida tropicalis isolates in HIV disease

Morphogenesis in Candida Albicans

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