The modern antimycotic era began with the introduction of griseofulvin in the 1950's, which had a tremendous impact on the management of dermatophytoses. Subsequent advances in therapy have lowered our threshold to treat recalcitrant cutaneous mycoses, such as onychomycosls. Newer generation antifungals including the triazoles, itraconazole and fluconazole, as well as the allylamine, terbinafine, may significantly reduce the prevalence of onychomycosis, as fungal nails are no longer incurable. The AIDS epidemic has been associated with an increase in the number of cutaneous and systemic mycotic infections. In spite of recent advances, organisms recalcitrant or resistant to therapy are common. Newer antifungal agents, improved diagnostic techniques, and standardization of fungal susceptibility testing are required to adequately treat patients with systemic and cutaneous mycoses.

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The dimorphic transition from yeast-to-mycelial growth is considered to be one of the virulence factors for the opportunistic pathogen Candida albicans. Although many investigations have been carried out during the last two decades, the mechanism of dimorphism and its contribution to the pathogenesis of C. albicans remains unknown. However, the rapid development of molecular genetic techniques now enables the analysis of gene expression during C. albicans morphogenesis. In this review, recent advances in differential gene expression during dimorphism in C. albicans are described, and possible avenues for the isolation of morphogenesis-specific genes are discussed.

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Adaptation of Aspergillus niger to amphotericin B (AMPH) and two imidazoles (miconazole (MCZ) and ketoconazole (KCZ)) was observed at a single hypha level with a continuous measurement system. It was found that a test hypha adapted to MCZ or KCZ was also adapted to AMPH but that a hypha adapted to AMPH was not adapted either to MCZ or KCZ. These adaptation phenomena to respective agents did not occur after incubation in the medium supplemented with ergosterol. The cross adaptation phenomena were suspected to be due to modification of the synthesis pathway of ergosterol and related derivatives.

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The non-dialyzable fraction of culture filtrate antigen of Aspergillus fumigatus was fractionated by anion exchange chromatography and gel filtration, connecting each column of Mono Q and Superose 6 sequentially. Fractions which had a high protein and reacted strongly with an immunoglobulin-M monoclonal antibody (MAb) 8-3C F5 G9, as determined by enzyme-linked immunosorbent assay (ELISA), were pooled to give four antigenic fractions (F1-F4). Gas-liquid chromatography analysis of the 4 antigenic fractions showed the presence of mannose and galactose. An immunoelectron microscopic experiment with MAb revealed the distribution of antigen on the surface of the hyphae. The fractions had no proteolytic activity. Fraction 4, relatively small in its molecular size but with the highest recovery of the reactivity with MAb among F1 to F4, was selected for further characterization. Antigenic reactivity of F4 with MAb was heat-stable but fully retained after sodium metaperiodate treatment. Pronase E almost destroyed the antigenic reactivity of F4 with MAb. MAb affinity chromatography of F4 gave the specific antigen, F4-AF. In both sodium dodecyl sulfate-polyacrylamide gel electrophoresis by Coomassie blue staining and Western blotting with MAb, F4-AF showed a single band with molecular mass of 66 kDa.

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A biocell-tracer developed by Matsuoka et al. determines the growth rate of single hyphae by monitoring their tips. This new apparatus was used to investigate the antifungal effect of miconazole (MCZ) on Aspergillus fumigatus.
Eight-tenths (1/4 MIC) to 6.25μg/ml (2 MIC) of MCZ completely inhibited the hyphal growth within 60min at 30°C, and 12.5 (4 MIC) to 100μg/ml (32 MIC) of MCZ did so within 20min.
Morphologically, when 0.8 to 1.6μg/ml of MCZ was added in an assay system hyphal tips became club-shaped, and when 3.2 to 25μg/ml of MCZ was added, hyphae formed short aberrant branches at the apical and subapical regions.
Next, examination of the effect of human serum containing 1.1μg/ml, 3μg/ml or 7.6μg/ml of MCZ on A. fumigatus showed that the latter amount inhibited the hyphal growth.
In conclusion, the biocell-tracer proved useful in this study on antifungal activity in filamentous fungi, and MCZ was suggested to be effective to treat systemic aspergillosis.

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Mitochondrial DNA restriction fragment length polymorphism was analyzed in 15 strains of Aspergillus fumigatus, 19 strains of A. neoellipticus, and 13 strains of Neosartorya fischeri. Their restriction patterns showed there were 3 types of A. fumigatus, 6 types of A. neoellipticus, and 2 types of N. fischeri. The restriction patterns were thus considered useful in the identification of species and discrimination of strains. Phylogenetic trees were prepared for each type based on the estimated values of the rate of base pair substitution in mtDNA. The results suggested that genetically A. fumigatus and A. neoellipticus are separate species, while A. neoellipticus may be anamorph of N. fischeri.

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Therapeutic effects of a traditional medicine, Juzen-taiho-to (TJ-48) against experimental fungal infections in mice were investigated. Normal or cyclophosphamide-treated immunosuppressed mice (ICR, female) were challenged intravenously with Candida albicans and given TJ-48 orally once daily for 5 consecutive days, beginning 3hr after C. albicans inoculation. The treatment with TJ-48 inhibited the Candida growth in kidneys of the infected mice, and prolonged their life span in a dose dependent manner with a optimal daily dose of 2.0g/kg. This therapeutic regimen was more effective than a prophylactic regimen, and when combined with the chemotherapeutic agent, fluconazole, efficacy was significantly increased. TJ-48 was found to be similarly efficacious against experimental infection by Aspergillus fumigatus, though not by Cryptococcus neoformans.

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The major membrane phospholipids of Candida albicans (C. albicans) are phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidylserine (PS). In Saccharomyces cerevisiae (S. cerevisiae), the most abundant component PC is considered to be synthesized mainly by two pathways; stepwise methylation pathway of PE produced from PS by decarboxylation (de novo pathway) and diacylglycerol (DG)/CDP-choline pathway. However, relatively little information is available regarding the phospholipid biosynthesis in C. albicans. In order to clarify the phospholipid metabolism of this organism, we have investigated the ³²Pi incorporation into different phospholipids by continuous and pulse-labeling in cells grown in the synthetic medium (SM) and yeast extractproteose peptone-dextrose (YPD) medium.
The continuous labeling with ³²Pi in YPD medium showed that the decreases in radioactivity in acidic phospholipids (PA, PI and PS) were followed by the great increase in PC, suggesting the existence of de novo pathway. In SM cultured cells showing no growth, PS and PI were heavily labeled, while PC was much less labeled. By the switch from SM to YPD, the rapid increase in ³²P-labeled PC occurred at the expense of PI and PS, suggesting that the principal PC synthesis for membrane biogenesis is via the de novo pathway in C. albicans.

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