Pathogenic fungi accumulate a quantity of pigments in mycelia and culture medium and it has been revealed that some of them are produced even by saprophytic fungi and possess hepato-toxicity to experimental animals. Several pigments have been isolated and their chemical structures have been determined. All pigments, whose structures have been clarified, are in dimer forms of naphthoquinone- or quinoid-compounds with lactone ring. Their biological activities are not fully understood. In our laboratory, chemical and biochemical properties of these pigments have been extensively investigated. Here, the obtained results are reviewed, and the relation between their biochemical properties and hepato-toxicities is also discussed. A strongly hydrophobic pigment, xanthomegnin which is most abundantly produced by various genera and species of dermatophytes, uncouples the oxidative phosphorylation, enhances the latent ATPase activity, and induces drastic swelling of mitochondria in rat liver. A quinoid pigment, floccosin, also exhibits a strong uncoupling effect on mitochondrial respiration. But the modes of action of floccosin on latent ATPase activity and swelling of mitochondria are not same as those of xanthomegnin, probably due to the difference in chemical structure. The molecular mechanism for the uncoupling activity of xanthomegnin on mitochondrial respiration was elucidated by the experiments with liposomes, purple membrane vesicles, and black lipid membranes. It has been, in addition, demonstrated that xanthomeginin undergoes enzymatic reduction by NAD-linked respiratory chain which results in electron transport shunt between NADH-dehydrogenase complex and cytochrome c in mitochondria.

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The taxonomic position of the pathogenic fungi were reviewed and the results of our mating studies on the Japanese isolates from animals were presented. The 6 isolates from canine and feline cryptococcosis were all identified as α type of Filobasidiella neoformans except one strain of untypable. The isolates of Microsporum canis from dogs and cats successfully mated were all revealed to be “-” mating type of Nannizzia otae except 3. The 2 out of 3 “+” strains were isolated in Hokkaido district. The canine and feline isolates of M. gypseum were identified to be N. gypsea and N. incurvata. In either species, there were no difference between the numbers of “+” and “-” isolates. The most of the animal isolates of Trichophyton mentagrophytes successfully mated were the “+” type of Arthroderma vanbreuseghemii.

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This paper deals with the conidial ontogenesis of black yeasts such as E. jeanselmei, E. gougerotti, E. dermatitidis and E. spinifera and a discussion of their phylogenesis. Conidial ontogenesis of E. jeanselmei, E. gougerotii and E. dermatitidis were almost the same. One to five annellated tips were observed at the apices of conidiogenous cells, which were bottle- or jar-shaped, by scanning electron microscopy. Annellations on the tips looked like fringes. Namely, the conidiogenous cells of these three species were annellides. These annellated tips were formed on hyphae and annelloconidia were also produced from them in the same way. Occasionally, secondary annellides were formed from the primary ones. They looked like monile-form hyphae. A daughter conidium sometimes budded directly from a mother one. The shapes and sizes of the conidia of these three species were almost the same. Conidial ontogenesis of E. spinifera was also annellidic. However, an annellated tip was usually formed on an annellide. The annellated tips of the fungus were long and more than 20 annellations were observed on their walls. There were no differences in the biological examinations except KNO₃ assimilation among these four species. The growth of E. jeanselmei and E. gougerotii was poor at 37°C. The GC contents of E. jeanselmei 1171, E. gougerotii CDC. B-1800, E. dermatitidis MM-7 and E. spinifera 2043 were 54.6, 54.6, 56.6 and 59.7%, respectively. The findings of the conidial ontogenesis and the results of the biological examinations and GC contents seem to suggest that these four species of Exophiala are related to basidiomycetous yeasts.

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Investigations so far made on induction and isolation of various types of mutants of Candida albicans and characteristics of some auxotrophic mutants were reviewed. Non-chromosomal, respiratory-deficient (“petitecolonie”) mutants of this pathogenic yeast induced by ethidium bromide were dealt to more details with special references to their biological properties concerned with the respiratory metabolism and those used as criterion for identification of C. albicans. There was an apparent relationship between the respiratory activity and the virulence for mice of this yeast.

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A high yield of protoplasts from Rhizoctonia solani Kühn was obtained with a combined enzyme system containing cellulase “onozuka” R-10 from Trichoderma viride, macerozyme R-10 from Rhizopus sp., and β-glucuronidase extracted from Helix pomatia gut juice. When 1g fresh weight of 15-hr-old mycelium was incubated with this enzyme mixture in 0.6M mannitol at pH 5.2, 6.0×10⁷ protoplasts were obtained within 3hr. The age of the mycelium strongly affected the yield of protoplasts. Intact protoplasts were separated from mycelial fragments and cell debris by aqueous two-phase system which consisted of 0.6M sucrose-0.6M mannitol. Purified protoplasts produced colonies after 48-72hr at 25°C. Intraspecific protoplast fusion after treatment with polyethylene glycol (PEG) has been described.

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A 39-year-old man was admitted to our hospital in January, 1979. His chief complaint was multiple subcutaneous abscesses with a violet red colored, board-like rigidity and sinuses in the back, buttock and lower extrimities. The lesions gradually developed since he had received wounds in the back in a traffic accident about two years before. At exploration, violet pus with “sulfur granules” was obtained. Gram positive branching filaments and rods were detected in smears of the granules. Anaerobic culture of the pus and of the granules yielded colonies abundant in gram positive, non acid-fast bacilli. We suspected them of Actinomyces. He was healthy generally and orodentally. The chest X-ray and barium enema were normal. The diagnosis of primary cutaneous actinomycosis was made. Shortly after admission, chemotherapy was commenced with intramuscular penicillin G, intravenous and oral ampicillin and oral sulfisomezole. Approximately six months of continued treatment primarily with penicillin brought about a perfect cure. Primary cutaneous actinomycosis is an extremely rare disease. It can be diagnos d only when the possibility of presence of a deeper focus has been excluded. Searce cases of the disease were mostly reported in Europe and North America.

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Alterations in phospholipid and fatty acid composition of Candida albicans were examined during the yeast cell to hypha transformation. The major phospholipids separated by thin layer chromatography were phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol/phosphatidylserine. Large increments of relative amounts of phosphatidylcholine and phosphatidylethanolamine with a profound decrement of phosphatidylinositol/phosphatidylserine were found to occur within 3 to 5h after the induction of the conversion. There was a great increase in linoleic (18:2) acid in all phospholipids, especially in phosphatidylcholine, with a compensatory decrease in the monounsaturated fatty acids. These alterations were considered to be confluent in the direction of increasing the degree of unsaturation, as ascertained by measuring the unsaturation indices. These alterations in cellular lipid composition were observed to coincide with the rapid elongation of the germ tubes. These results suggest that modification of membrane lipid composition might be associated with the transformation from yeast cell to hypha in C. albicans.

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A case of black dot ringworm caused by Trichophyton rubrum was reported. A 49-year-old woman visited our office complaining of her scaly erythematous eruptions of one year duration on her almost whole body. She was treated successfully by anti-fungal agents under diagnosis of tinea corporis, however, the rash relapsed eleven months later. In addition to the widespread lesions of tines corporis, nemerous black dots were seen on the parietooccipital area of the head. Light microscopic examination of the infected hairs showed large spores of the endothrix type. Wood's lamp examination was negative. Nails were also thickened and brittle. Physical examination revealed that she suffered from Cushing's syndrome. In macroscopic appearance, the center of thalli was heaped up and red pigment was beneath the thalli. Microscopically, longstrands of hyphae with tearshaped microaleuriospores and a small number of cylindrical form macroaleuriospores were observed. The production of red pigment on corn meal dextrose agar was also confirmed. Although the report of black dot ringworm was increased in Japan, only three cases out of 63 were caused by Trichophyton rubrum.

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Ketoconazole (KCZ), a recently synthesized water-soluble imidazole derivative, showed a broad antifungal spectrum in vitro. In the case that inoculum size were 10⁶cells/ml, KCZ inhibited the wide range of pathogenic fungi with geometric mean MIC values of 71.6μg/ml against Candida albicans, 0.62-80μg/ml against another Candida species, 1.76-7.94μg/ml against yeasts and yeast like fungi except Candida, 0.63-20μg/ml against dermatophytes, 1.25-2.5μg/ml against dematiaceous fungi, 1.25-20μg/ml against Aspergillus, 8.41μg/ml against Sporothrix schenckii, 0.62-5μg/ml against Trichosporon and 80μg/ml against Fusarium solani. KCZ was less active against bacteria with the MIC value of over than 100μg/ml against most of the bacteria including Staphylococcus aureus, Streptococcus pyogenes and anaerobic bacteria. The influences of various factors such as component of assay medium, incubation period, inoculum size, addition of serum and pH of assay medium affecting on MIC values for KCZ were investigated. On Sabouraud's glucose agar medium, the anti-Candida activity of KCZ were increased about 1, 000 times with the shift of pH of the medium from pH 3 to pH 8.

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Patient: 24-year-old woman. On November 18, 1981, she kept a catling which had crustling lesions on the scalp. Three days after the breeding, the cat went away from her house. On November 26, pale red erythematous lesions developed on her neck. A few days after, the periphery lesion enlarged rapidly while the center portion became depressed, and at the same time erythematous lesions were scattered on the neck, breast, right arm and left lower leg. Microsporum canis were isolated from her skin lesions. We were unable to see the catling, but the infection may be traced from the cat. Because the catling sleeped in her neck and initial lesions developed on her neck. These results indicate, when the subjects come into contact with infected animals closely, the primary lesions of Microsporum canis infection may develope at the site inoculation after an incubation period of about 5 to 8 days.

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