In the period from 1992 to 2001, 303 cases of nocardioses were diagnosed in Japan, with the corresponding etiological agents isolated and characterized. Taxonomic analyses of these 303 strains showed that most nocardial infections were caused by members of the Nocardia asteroides group (72.3%). Speciation showed that 72 strains were N. asteroides, 31 strains were N. cyriacigeorgica, 2 strains were N. beijingensis, 81 strains were N. farcinica, and 33 strains were N. nova. Sixty-six strains of N. brasiliensis were the next most prevalent species of the total Nocardia isolates, followed by 14 strains of N. otitidiscaviarum. Infections by N. transvalensis (3 strains) and N. pseudobrasiliensis (1 strain) were also confirmed. The infections due to N. transvalensis, N. cyriacigeorgica, and N. beijingensis were the first reported in Japan. The most common factor that predisposed individuals to nocardial infection in Japan was therapy by immunosuppressive agents (22.4%), including SLE therapy (3.6%), followed by cancer (6.6%), diabetes (3.6%) and AIDS (2.0%). Nocardial infections occurred more commonly in the elderly, with most of the patients between the ages of 61 and 80 years of age. No significant difference regarding infectivity levels between the sexes was observed.

Sequences of the internal transcribed spacer (ITS) region including the 5.8S rRNA gene delineated seven genotypes within the three varieties of Cryptococcus neoformans via specific combinations of eight nucleotide differences located at positions 10, 11, 15, 19, 108 (ITS1), 221 (5.8S), 298 and 346 (ITS2). The ITS types correlated to polymerase chain reaction fingerprint/random amplification of polymorphic DNA (RAPD) molecular types: with ITS type 1 (ATACTAGC)=C. neoformans var. grubii, molecular types VNI+VNII and the serotype A allele of the AD hybrid, VNIIIA; ITS type 2 (ATATAGGC)=the serotype D allele of the AD hybrid, VNIIIB, and C. neoformans var. neoformans, VNIV; and ITS type 3 (GCGCTGGC) and ITS type 7 (ACGCTGGC)=VGI=RAPD type III, ITS type 4 (ACACTGAC)=VGII=RAPD type II, ITS type 5: (ACACTGGG)=VGIII=RAPD type I, ITS type 6 (ACACTGGC)=VGIV=RAPD type IV, all corresponding to C. neoformans var. gattii. Cloned sequences from serotype AD revealed that the hybrid serotype is diploid at the ITS1-5.8S-ITS2 locus carrying the ITS type 1 (ATACTAGC) and the ITS type 2 (ATATAGGC) alleles. ITS sequencing is a useful technique for genotyping the three C. neoformans varieties and for subtyping within C. neoformans var. gattii.

The characteristics of in vitro micafungin (FK463) antifungal activity against six species of dimorphic fungi were investigated in accordance with the NCCLS M27-A microdilution methods. MICs of micafungin, amphotericin B, itraconazole, and fluconazole for Histoplasma capsulatum var. capsulatum, Blastomyces dermatitidis, Paracoccidioides brasiliensis, Penicillium marneffei, and Sporothrix schenckii were determined both for the yeastlike form and mycelial form. Coccidioides immitis was tested only in its mycelial form. We have clearly demonstrated that the in vitro activity of micafungin depends considerably on the growth form of dimorphic fungi. Micafungin exhibited potent activity against the mycelial forms of H. capsulatum, B. dermatitidis, and C. immitis (MIC range, 0.0078 to 0.0625 g/ml), while it was very weakly active against their yeast-like forms (MIC range, 32 to >64 g/ml). Micafungin was also more active against the mycelial forms than the yeast-like forms of Paracoccidioides brasiliensis, Penicillium marneffei, and S. schenckii. The MICs of amphotericin B were 2 to 5 dilutions lower for the mycelial forms than for the yeast-like forms of B. dermatitidis and Paracoccidioides brasiliensis. There was no apparent difference in the activity of itraconazole between the two forms. The MICs of fluconazole for the yeast-like forms were generally lower than those for the mycelial forms, and considerably so for B. dermatitidis. These results suggest that the growth form employed in antifungal susceptibility testing of dimorphic fungi can considerably influence the interpretation of results. At present, it cannot be judged whether micafungin has clinical usefulness for dimorphic fungus infections, since for most fungi it remains uncertain which growth form correlates better with therapeutic outcome. However, the results of this study warrant further investigations of micafungin as a therapeutic agent for infections caused by dimorphic fungi.

The genetic diversity of recent clinical isolates of Candida albicans in Japan was studied on the basis of amplified DNA band lengths determined with a specific PCR primer reported to have been designed to span a transposable intron region in the 25S rRNA gene. Our analyses of 301 clinical isolates of C. albicans showed that they could be classified into five genotypes: genotype A (172 isolates), genotype B (66 isolates), genotype C (56 isolates), genotype D (C. dubliniensis; 5 isolates), and a new genotype (designated genotype E; 2 isolates). The new genotype E was characterized to have a group I intron-like sequence, which is longer than hitherto reported ones and which has a nucleotide sequence length of 962 bp. Our analysis of the 962-bp sequence indicated that it is composed of an intron similar to that of C. dubliniensis of 621 bp with a 341-bp insertion. Analysis of the sequence of the internal transcribed spacer (ITS) region of the genotype E strain showed that its sequence is identical to those of strains of other genotypes, with only a few base substitution differences. Throughout the study, the possible horizontal transfer of the group I intron between C. dubliniensis and C. albicans was suggested. A high degree of correlation between the presence of a group I intron in C. albicans genotype E and susceptibility to the antifungal agent flucytosine was observed. The five isolates of C. dubliniensis examined in the present study showed genetic diversity when they were compared by randomly amplified polymorphic DNA fingerprinting pattern analysis, and this diversity was also confirmed by the analysis of ITS region sequences.

We describe, to our knowledge, the first case of allergic bronchopulmonary mycosis (ABPM) caused by the basidiomycetous fungus Schizophyllum commune in an otherwise healthy woman. Bronchoscopic analysis repeatedly disclosed S. commune hyphae in the bronchi of the lingular lobe; these hyphae were originally misidentified as Aspergillus because the presence of clamp connections was overlooked. A lingular infiltrate with ectatic proximal bronchi, eosinophilia, an elevated serum level of IgE, and antibodies to S. commune supported the diagnosis. It is sometimes difficult to isolate and identify S. commune in clinical specimens, and hence only a limited number of cases of ABPM might have been correctly diagnosed in the past. We suspect, therefore, that some cases of ABPM caused by an allergic reaction to S. commune may be misdiagnosed as allergic bronchopulmonary aspergillosis or eosinophilic pneumonia of unknown origin. The significance of S. commune in allergic bronchopulmonary diseases is discussed.