Background: Dermatophytes are the main cause of onychomycoses, but various non-dermatophyte filamentous fungi are often isolated from abnormal nails. Objective: Our aim was the in situ identification of the fungal infectious agent in 8 cases of onychomycoses which could not be cured after systemic terbinafine and itraconazole treat- ment. Methods: Fungal DNA was extracted from nail samples, and infectious fungi were identified by restriction fragment length polymorphism (RFLP) of amplified fungal ribosomal DNA using a previously described PCR/RFLP assay. Results: PCR/RFLP identification of fungi in nails allows the identification of the infectious agent: Fusarium sp., Acremonium sp. and Aspergillus sp. were found as a sole infectious agent in 5, 2 and 1 cases, respectively. Conclusions:Fusarium spp. and other non-dermatophyte filamentous fungi are especially difficult to cure in onychomycoses utilising standard treatment with terbinafine and itraconazole. PCR fungal identification helps demonstrate the presence of moulds in order to prescribe alternative antifungal treatments.

Background: Tinea capitis is a worldwide-spread infection of the scalp caused by dermatophytes and is predominantly seen in children. The clinical manifestations range from mild scaling lesions to widespread alopecia or highly inflammatory suppurating lesions. Terbinafine and itraconazole seem to be promising therapies with shorter treatment durations than griseofulvin. Objective: The objective of the present study was to test the sensitivity of different species of dermatophytes towards terbinafine and itraconazole, and to compare the results with a retrospective study on 35 immunocompetent patients with tinea capitis who were treated with terbinafine (Lamisil^®). Methods: Minimal inhibitory concentrations (MIC) were measured with an agar dilution method. Results: Each tested species of dermatophyte was sensitive to terbinafine and itraconazole at different concentration ranges. The MIC for terbinafine ranged from 0.005 to 0.5 μg/ml and for itraconazole from 40 to 80 μg/ml. Microsporum canis was the dermatophyte least sensitive to terbinafine. Our retrospective study showed that the cure rate was excellent for Trichophyton violaceum and T. soudanense, variable for T. mentagrophytes and poor for M. canis and M. langeronii. Conclusions: (i) Regarding the results of susceptibility tests obtained with species involved in tinea capitis, clinical efficacy is not related to MIC measured in vitro; (ii) identification of the isolated dermatophyte from tinea capitis seems to be important for choosing the appropriate treatment.

Summary. Epidemiological studies require characterisation of pathogenic yeasts at and below the species level. The chromosomes of 130 strains of four pathogenic species of the genus Candida, isolated from clinical material, were separated by pulsed field electrophoresis with the clamped homogeneous electric field (CHEF) technique. Each species was characterised by a distinct electrophoretic karyotype (EK). Furthermore, smaller variations of the EK amongst strains belonging to the same species appeared to offer a useful means of strain differentiation. A karyotyping system is proposed for C. albicans. The EKs were assigned to a code of four numbers which designated the number of bands that could be resolved in each of four sets of chromosomes. Morphotypes of the colonies of C. albicans on malt agar plates, which did not correlate with the EK, could provide a complementary means of strain characterisation in epidemiological studies.

Background: Dermatophytes are the main cause of onychomycosis, but various non-dermatophyte moulds (NDMs) are often the infectious agents in abnormal nails. In particular, Fusarium spp. and other NDMs are mostly insensitive to standard onychomycosis treatment with topical agents as well as with oral terbinafine and itraconazole. Objective: The aim of this work is to report the efficacy of a topical amphotericin B solution on NDM onychomycosis in a series of 8 patients resistant to multiple conventional topical and systemic treatments. Methods: Treatment consisted in the application of an optimized amphotericin B solution once daily to the affected nails and surrounding tissue. No mechanical debridement or medications were allowed except for trimming excessively long nails or in some cases occasionally applying urea-based cream to soften thickened nail plates. Results: Onychomycosis was clinically cured in all patients after a 12-month treatment. Mycological cure was obtained in all but 1 patient. Conclusions: Topical amphotericin B is an efficacious, safe, cheap and easy-to-apply treatment which should be considered as first-line therapy for NDM onychomycosis.

Direct examination for fungi in skin and nail scrapings can be done by light microscopy with or without staining, or by fluorescence miroscopy using specific fluorochromes for the fungal cell wall constituants. The principal techniques described in the literature and two new methods (Congo red and Na₂S-Blankophor P flüssig) were compared for their efficiency and rapidity.

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Background: Fusarium onychomycoses are weakly responsive or unresponsive to standard onychomycosis treatments with oral terbinafine and itraconazole. Objective: To examine whether the use of terbinafine and itraconazole, which are highly effective in fighting Trichophyton onychomycoses, could be a cause of the high incidence of Fusarium nail infections. Methods: Polymerase chain reaction methods were used to detect both Fusarium spp. and Trichophyton spp. in nails of patients who had either received treatment previously or not. Results: No significant microbiological differences were found between treated and untreated patients. In 24 of 79 cases (30%), Fusarium spp. was detected in samples of patients having had no previous antifungal therapy and when Trichophyton spp. grew in culture. Conclusion: Oral terbinafine and itraconazole treatments do not appear to favor the establishment of Fusarium spp. in onychomycosis.