Micafungin (MCFG) is a new lipopeptide antifungal agent of the echinocandin class. MCFG inhibits 1, 3-β-D-glucan synthesis in C. albicans and A. fumigatus in a non-competitive manner, and has antifungal activity against both Aspergillus and Candida species. In neutropenic mouse models of disseminated candidiasis and pulmonary aspergillosis, the efficacy of MCFG was superior to that of fluconazole and itraconazole, but comparable to that of amphotericin B.
The efficacy and safety of MCFG were investigated in 70 patients with deep-seated mycosis caused by Candida and Aspergillus species. The overall clinical response rates were 57.1% in aspergillosis and 78.6% in candidiasis. The incidence of adverse events related to micafungin was 17.9%, and there was no dose-related occurrence of any adverse events. The results from this study indicated that micafungin was effective in aspergillosis and candidiasis, with no tolerability problems.

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Voriconazole (VRCZ) is an azole-class antifungal agent with a broad spectrum. VRCZ shows high antifungal activity to Candida spp. including fluconazole less-susceptible species., Aspergillus spp. and Cryptococcus spp. VRCZ shows fungicidal activity to Aspergillus spp. In addition, voriconazole shows activity to rare pathogens like Fusarium spp. or Scedosporium spp. VRCZ is available in both IV and oral formulation. The oral formulation shows stable and almost 100% bioavailability. The protein binding ratio is approximately 58% and over 40% exists as unbound form. VRCZ shows a good tissue distribution including brain and CSF.
Outside Japan, several RCTs were conducted for the treatment of deep seated mycosis. The results show a very good drug profile superior to the existing antifungal agents.
VRCZ was approved by the FDA and EMEA in 2002. As of September 2004, it has been approved in over 50 countries worldwide.

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Liposomal amphotericin B (AmBisome™) is a DDS (drug delivery system) formulation of amphotericin B (AMPH-B), and has been developed in an attempt to reduce the toxicity of AMPH-B while retaining its therapeutic efficacy. AMPH-B has been the “gold standard” of antifungal therapy over the past four decades. It has a broad spectrum of fungicidal activity against a number of clinically important pathogens including Aspergillus and Candida. The mechanism of action of AMPH-B involves binding to ergosterol, the principal sterol in fungal cell membranes. Binding to ergosterol causes an increase in fungal membrane permeability, electrolyte leakage, and cell death. AMPH-B has affinity for cholesterol in mammalian membranes, which leads to severe side-effects including kidney damage.
AmBisome is a unilamellar vesicle composed of AMPH-B and phospholipid. Upon administration, AmBisome remains intact in the blood and distributes to the tissues where fungal infection may occur, and is disrupted after attachment to the outside of fungal cells, resulting in fungal cell death.
AmBisome and AMPH-B show similar in vitro and in vivo antifungal activity and clinical efficacy. However, AmBisome has less infusion-related toxicity and nephrotoxicity than AMPH-B.

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Candida albicans is the most common fungal opportunistic pathogen in humans. The AIDS epidemic, improved life-sustaining therapy, and aggressive anticancer therapy have contributed to a rise in the number of severely immunocompromised patients. This has led to an increase in oral and systemic fungal infection. Several factors, such as adherence, persistence, dimorphism, germ tube formation, and/or contact sensing, phenotypic switching, interference with the host defense system, synergism with bacteria, and the production of hydrolases or other metabolites, have been proposed to be virulence factors of this fungus. Among these virulence factors, adherence and persistence are thought to be the most important, since the colonization and subsequent biofilm formation of oral surfaces may serve as a reservoir for disseminated infections, such as aspiration pneumonia and gastrointestinal infection. In the review, we summarized the factors involved in the Candida albicans biofilm formation.

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Respiration-deficient (petite) mutation is caused by hereditary impairment in mitochondrial functions. Yeasts have been grouped into “petite-positive” and “petite-negative” yeasts. Candida albicans has been regarded as a member of the petite-negative yeasts in which the respiration deficiency cannot be easily induced. We have succeeded in inducing the petite mutation in C. albicans by culturing in the presence of a chemical mutagen, acriflavine, at an elevated temperature. In the present review, we describe the cell biology of C. albicans petite mutants on the basis of experiments performed by our research group: namely, on respiratory activity and cytochrome composition, fine structures of cells and mitochondria, mitochondrial DNA structure, pathogenicity, oxidative stress sensitivity, generation of reactive oxygen species (ROS) and the roles of ROS in antifungal actions. We discuss also the usefulness of petite mutants in Candida research.

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ABC (ATP binding cassette) transporters consist of transmembrane domains which confer specificity, and structurally conserved nucleotide binding domains that contain highly conserved amino acid motifs. They act not only as transporters but also as receptors or channels that use energy generated by ATP hydrolysis. ABC transporters are widely dispersed in nature. They are found in cells ranging from prokaryotes (bacteria) to eukaryotes (including humans) and several are considered to play crucial roles in cellular homeostasis. Defects in ABC transporters in humans are associated with severe diseases such as type 2 diabetes and cystic fibrosis. Some ABC transporters extrude xenobiotics and confer resistance to chemotherapeutics on microbial pathogens and cancer cells. Thus ABC transporters are of considerable medical importance. Structure-function analysis of ABC transporters has begun to elucidate their mechanisms of substrate recognition, the functional regulation of ATP-binding and hydrolysis and to identify intrinsic physiological functions. In pathogenic fungi, ABC transporters contribute to the clinical problem of drug resistance. The application of new technologies to the examination of fungal ABC transporter function is providing new insights into the use of antifungal drugs in medical mycology and contributing to a better understanding of these important membrane proteins.

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Isolates of Exophiala jeanselmei have been classified into 15 types based on their mitochondrial DNA (mtDNA). Thirteen of the 15 types and E. spinifera, which has been classified as E. jeanselmei Type 14, were confirmed to be also clearly differentiated by restriction fragment length polymorphism (RFLP) in internal transcribed spacer (ITS) regions of ribosomal RNA genes in their nuclear DNA (nDNA). Twenty strains of E. jeanselmei, newly identified or isolated from patients in Japan, were examined for mtDNA-RFLP and ITS-RFLP. The twenty isolates were comprised of: 11 E. jeanselmei Type 5, 6 E. jeanselmei Type 6, 2 Type 10, and 1 Type 8. E. jeanselmei Type 6 was the second most common strain in Japan after Type 5. Type 5 was definitely identified as E. jeanselmei var. jeanselmei and Type 8 was identified as E. jeanselmei var. lecanii-corni based on the genotypes of type strains of these species. However, two other types were still designated as E. jeanselmei Type 6 and E. jeanselmei Type 10.

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A 74-year-old woman presented in April, 2003, with cutaneous lesions of the face by Paecilomyces lilacinus infection. The patient had received predonisolone and azathioprine for 20 months for treatment of autoimmune hemolytic anemia. The lesion first developed on the right lateral eyelid 1.5 years earlier, and gradually enlarged. Physical examination revealed a dark reddish or brownish plaque and scattered papules and abscesses around the plaque on right lateral and lower eyelids, and the cheek. She noted mild tenderness on pressure. Cultures obtained from pus and biopsy specimen showed moulds, and those were identified as Paecilomyces lilacinus. Griseofulvin, 500mg per day, was not effective for the lesion, so itraconazole, 200-300mg per day, was administered orally for 11 weeks. Since culture from pus still yielded P. lilacinus despite clinical effectiveness, itraconazole pulse therapy (400mg daily, 7 days a month) was started. The lesion cleared after three cycles of the pulse therapy.

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A 74-year-old woman visited a clinic in Kisarazu, Chiba Prefecture in December 2002 complaining of itching, scale and alopecia. She had been diagnosed as having tinea capitis by a direct microscopic examination of scales, and been treated with an antifungal cream and steroid lotion since 1999. The bald area spread from frontal to occipital in which multiple black dots and red papules were scattered. Abundant endothrix spores were observed in the hair shaft. A mycelial colony was isolated from the black dots. A giant colony on Sabouraud's agar was white, powdery and flattened with cottony elevation at the center in the obverse, and a reddish-brown pigmentation in the reverse. The isolate produced abundant microconidia that were round to club-and balloon-shaped with extreme swelling, while macroconidia and spiral bodies were few. Hair perforation test was negative and urease activity test was positive. ITS1-5.8S-ITS2 rDNA sequencing revealed 100% homology with T. tonsurans isolated from two old women in Niigata Prefecture. On the other hand, 3 bases were different from those of the outbreak isolates from judo and wrestling players infected through international matches. T. tonsurans has polymorphism and the present isolate might be an autochthonous genotype in Japan. This is the first time T. tonsurans was isolated in Chiba Prefecture. But this prefecture had been known as an endemic area of Trichophyton coccineum, which was very similar in morphological and physiological characteristics to those of T. tonsurans before World War II. These facts raise the question of whether T. tonsurans has existed in this prefecture before.

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Six cases of Trichophyton (T.) violaceum infection seen in a nursing home are reported. A 66-year-old female (case 1) was found with tinea corporis on her face, chest and shoulder, associated with black dot ringworm. A KOH examination of hair showed endothrix parasitism. Reddish purple colonies were isolated from the patient on Sabouraud's dextrose agar, and intercalary and terminal chlamydospores were observed on slide culture. PCR-RFLP analysis of the microorganism showed a pattern of T. violaceum type. Therefore, the isolated fungus was identified as T. violaceum, a typical anthropophilic dermatophyte which had spread among residents and staffs easily. Using a mycological method, we examined 59 persons (21 residents and 38 staff members) who had had contact with case 1. The results were as follows. An 85-year-old female (case 2) and an 83-year-old female (case 3) were carriers of T. violaceum. A 23-year-old male (case 4) had tinea corporis on his right forearm due to T. violaceum. A 24-year-old male (case 5) probably had tinea corporis on his right forearm due to T. violaceum. One year after case 1's first visit to our clinic, we observed an 88-year-old female (case 6) of tinea capitis by T. violaceum. It seems that the organism was preserved in surroundings and members of the nursing home. The contagion in our cases could either have been caused by directly touching the person or by sharing their comb. PCR-RFLP analysis was performed within a short time, so that we managed effectively to select a way of treatment and to prevent the infection from spreading.

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A total of 168 patients with tinea pedis, but without onychomycosis, were treated with 1 cycle of terbinafine (TBF) (1 cycle: defined as 250mg/day for 1 week). KOH preparation for direct microscopy was performed 4, 8 and 12 weeks after starting therapy to determine if testing was positive for tinea. Patients with no negative results on KOH examination or no evidence of obvious clinical improvement at 8 weeks, another cycle of the therapy was prescribed. The “cure, ” “no cure, ” “dropout, ” and “discontinuation/unevaluable” rates were 89.3%, 4.8%, 4.8% and 1.2%, respectively. The number of cycles required for cure in the plantar type was 1 cycle in 65.9% and 2 cycles in 54.5% of cases; in the interdigital type, 1 cycle in 79.1% and 2 cycles in 20.9% of cases; and mixed type, 1 cycle in 29.1% and 2 cycles in 60.9% cases. Among patients who were followed for at least 3 years after cure, the relapse rates were about 10% each year: 1 year, 11.3%; 2 years, 8.9%; and 3 years, 11.2%. The relapse rate of about 10% each year over a 3-year period suggests that reinfection may be likely.

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In order to confirm the phylogenetic relationships of Histoplasma capsulatum, the partial sequences of large subunit (28S) ribosomal gene (D1/D2 region) of 49 isolates were studied. The similarity values of the 49 isolates were more than 99.0% across 617 base pairs, however, the 49 isolates were divided into 9 groups. These 9 groups were independent of 3 varieties, var. capsulatum, var. farciminosum and var. duboisii. These results showed that analysis of the nucleotide sequence of the 28S rRNA gene was very effective for identification of H. capsulatum and that three varieties of H. capsulatum should be reclassified according to the phylogenetic relationship established from analysis of the D1/D2 region sequences.

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