Hyperthermic treatment of chromomycosis with disposable chemical pocket warmers

A case of chromomycosis in which hyperthermia proved effective is reported. The patient was a 56-year-old male bean curd maker who, without any previous history of minor trauma, developed on the extensor side of the left upper arm an eczematous lesion that underwent gradual radial expansion. The lesion showed a well-defined, 7×10 cm infiltrated erythematous plaque with the central area healed and, at the upper and lower borders, adherent scales and crusts on the surface. Histological examination revealed granulomatous changes in the dermis, as well as sclerotic cells within giant cells and microabscesses. On culturing,Fonsecaea pedrosoi was isolated. The patient was treated with disposable chemical pocket warmers, which were secured over the lesion with a rather tight elastic bandage, so that they kept the affected area warm for 24 hours a day. After a month of such hyperthermic treatment, the erythema and infiltration had decreased considerably, and microscopic examination and culture of the crusts both yielded negative results. Examination of biopsy specimens of the lesion after the third month showed that it had cicatrized. The treatment was stopped after 4 months, and no relapse occurred. We also summarize the published results of local hyperthermic treatment of chromomycosis in Japan.     

Divergence Among an International Population of Trichophyton tonsurans Isolates

Trichophyton tonsurans is a widely distributed pathogen that demonstrates a significant degree of genetic and phenetic heterogeneity. To date, the degree of genetic relatedness among geographically segregated isolates has not been explored. This investigation evaluates the extent of genetic variation among an international population of T. tonsurans isolates and examines the relatedness of isolates within and between countries. Molecular strain typing was performed on 198 isolates obtained from 14 countries. A mixed-marker strategy utilizing 27 sequence variations in 13 gene loci was applied to all isolates and cluster analysis was performed to examine the relationship between strains. Phylogenetic analysis was used to corroborate the findings of the cluster analysis with T. equinum strains serving as an out-group. In total, 47 distinct strain types were identified represented by seven clusters and one singleton. There appeared to be a moderate degree of clustering among isolates obtained from North America, Asia and Australia, although European isolates were uniformly distributed among the majority of clusters. The degree of genetic variation observed in this study coupled with the geographic localization would support the argument for allopatric divergence within this species.     

Candida albicans abrogates the expression of interferon-gamma-inducible protein-10 in human keratinocytes

Candida albicans is the predominant causative agent of human cutaneous candidiasis. Epidermal keratinocytes play an important role in the cutaneous immune response through the production of cytokines and chemokines, including IFN-gamma-inducible protein 10 (IP-10). Here, we investigated the influence of C. albicans infection on IP-10 production by normal human epidermal keratinocytes (NHEK) in vitro. Our results showed that IFN-gamma-stimulated NHEK showed enhanced IP-10 mRNA and protein expression; this expression was downregulated by C. albicans infection. Candida tropicalis also impaired IFN-gamma-induced IP-10 expression, but Candida glabrata did not. Heat-killed C. albicans did not impair IFN-gamma-induced IP-10 expression. We found that coincubation of NHEK with live C. albicans without cell-to-fungi contact impaired IFN-gamma-induced IP-10 mRNA and protein expression in NHEK, suggesting the role of soluble factors derived from live C. albicans in this impairment. Enzyme-linked immunosorbent assay analysis revealed that C. albicans and C. tropicalis could produce marked levels of prostaglandin (PG) E(2), while C. glabrata produced low levels of this prostaglandin. Treatment with E-series prostaglandin receptor antagonists, AH6809 and AH23848, restored IFN-gamma-induced IP-10 expression in C. albicans-infected NHEK. Thus, Candida-derived PGE(2) may impair IFN-gamma-induced IP-10 expression in human keratinocytes and may play a role in the pathogenesis of cutaneous candidiasis.     

Ultrastructure of Sporothrix schenckii treated with iodine-potassium iodide solution

The ultrastructural changes produced by iodine-potassium iodide solution on yeast cells of Sporothrix schenckii were investigated by transmission electron microscopy in order to clarify the mechanism of oral potassium iodide therapy for sporotrichosis. Yeast cells were dipped with solutions containing various concentrations of iodine. The rate of germination decreased markedly between the range of iodine concentrations from 0.63 g/ml to 5.0 g/ml. No significant ultrastructural changes were seen at the concentration of the iodine of 1.25 g/ml (80% germination) or less. In the concentration of 2.5 g/ml (50% germination), normal cells and degenerated cells coexisted. When the cells were treated with 5.0 g of iodine per ml (0% germination) or more, their interior structures were completely destroyed. It is assumed that iodine treatment of the organism causes rapid destruction in the whole cell.     

Genotype Analyses of Human Commensal Scalp Fungi,Malassezia globosa,and Malassezia restricta on the Scalps of Patients with Dandruff and Healthy Subjects

Dandruff and seborrheic dermatitis are common afflictions of the human scalp caused by commensal scalp fungi belonging to the genus Malassezia. Malassezia globosa and Malassezia restricta are the predominant species found on the scalp. The intergenic spacer regions of these species’ rRNA genes contain short sequence repeats (SSR): (GT)n and (CT)n in M. globosa and (CT)n and (AT)n in M. restricta. In the present study, we compared the genotypes (SSR) of M. globosa and M. restricta colonizing the scalps of patients with dandruff and healthy individuals. For M. globosa, the genotype (GT)₁₀:(CT)₈ (40.3 %, 25/62) was predominant followed by (GT)₉:(CT)₈ (14.5 %, 9/62) and (GT)₁₁:(CT)₈ (14.5 %, 9/62) in patients with dandruff, whereas the genotypes in healthy subjects were diverse. For M. restricta, the genotype (CT)₆:(AT)₆ (59.7 %, 37/62) was predominant followed by (CT)₆:(AT)₈ (24.2 %, 15/62) in patients with dandruff, while four genotypes, (CT)₆:(AT)₆ (10.5 %, 6/57), (CT)₆:(AT)₇ (22.8 %, 13/57), (CT)₆:(AT)₈ (17.5 %, 10/57), and (CT)₆:(AT)₁₀ (21.1 %, 12/57), accounted for 71.9 % of all combinations in healthy subjects. The results of this study suggest that the M. globosa genotype (GT)₁₀:(CT)₈ and the M. restricta genotype (CT)₆:(AT)₆ may be involved in the development of dandruff.     

Localized cutaneous nocardiosis in Japan

A turbidometric method was used to measure Candida albicans yeast cell growth and to quantitate the postantifungal effect (PAFE) after exposure to various concentrations of flucytosine and amphotericin B, alone and in combination, for 2 hr at 30°C. The drug concentrations used in the PAFE assays were determined by initial MIC and FIC (fractional inhibitory concentration) evaluations. The PAFE was calculated by the difference in time (hr) required for growth of the control and test cultures to reach the 0.5 absorbance level following removal of the drug by dilution. A synergistic PAFE was evidenced with combinations of the two drugs at concentrations below their individual MICs. Combinations of flucytosine (0.012 to 0.049 g ml^–1) and amphotericin B (0.195 to 0.39 g ml^–1) produced PAFEs ranging from 6.3 to 21.8 hr. These PAFEs persisted from 0.3 to 14.7 hr longer than those achieved when each of the two agents was assayed separately.     

Genotype analysis of the variable internal repeat region in the rRNA gene of Trichophyton tonsurans isolated from Japanese Judo practitioners

Tinea capitis due to Trichophyton tonsurans is currently epidemic among Japanese Judo practitioners. T. tonsurans has seven genotypes in a variable internal repeat (VIR) region of the rRNA gene. All 101 isolates obtained from Japanese Judo practitioners had the identical genotype. This suggests that a specific genotype strain occurs throughout Japan.