The human mutilating disease chromoblastomycosis is caused by melanized members of the order Chaetothyriales. To assess population diversity among 123 clinical strains of agents of the disease in Brazil we applied sequencing of the rDNA internal transcribed spacer region, and partial cell division cycle and β-tubulin genes. Strains studied were limited to three clusters divided over the single family Herpotrichiellaceae known to comprise agents of the disease. A Fonsecaea cluster contained the most important agents, among which F. pedrosoi was prevalent with 80% of the total set of strains, followed by 13% for F. monophora, 3% for F. nubica, and a single isolate of F. pugnacius. Additional agents, among which two novel species, were located among members of the genus Rhinocladiella and Cyphellophora, with frequencies of 3% and 1%, respectively.
Sporotrichosis is a subacute or chronic mycosis caused worldwide by the dimorphic species complex, Sporothrix schenckii. We studied 85 isolates recovered in Brazil to verify their identification and evaluate their in vitro antifungal susceptibility patterns. Based on phenotypic tests (microscopic features, ability to grow at 30°C and 37°C, colony diameters, as well as assimilation of sucrose and raffinose) and molecular assays (amplification of a fragment of the calmodulin gene), the strains were identified as S. schenckii, S. brasiliensis and S. globosa, with a predominance of S. schenckii isolates. There was 37.7% disagreement between the phenotypic and genotypic identification methodologies. In general, terbinafine was the most active drug, followed by ketoconazole and itraconazole, and the less active fluconazole and voriconazole. Five isolates (one S. globosa and four S. schenckii) were found to be itraconazole-resistant strains but, in general, there were no differences in the in vitro antifungal susceptibility profiles among the Sporothrix species.
Fusarium species have emerged as an important human pathogen in skin disease, onychomycosis, keratitis and invasive disease. Onychomycosis caused by Fusarium spp. The infection has been increasingly described in the immunocompetent and immunosuppressed hosts. Considering onychomycosis is a difficult to treat infection, and little is known about the genetic variability and susceptibility pattern of Fusarium spp., further studies are necessary to understand the pathogenesis and better to define the appropriate antifungal treatment for this infection. Accordingly, the objective of this study was to describe the in vitro susceptibility to different antifungal agents and the genetic diversity of 35 Fusarium isolated from patients with onychomycosis. Fusarium spp. were isolated predominantly from female Caucasians, and the most frequent anatomical location was the nail of the hallux. Results revealed that 25 (71.4%) of isolates belonged to the Fusarium solani species complex, followed by 10 (28.5%) isolates from the Fusarium oxysporum species complex. Noteworthy, the authors report the first case of Neocosmospora rubicola isolated from a patient with onychomycosis. Amphotericin B was the most effective antifungal agent against the majority of isolates (60%, MIC ≤4 μg/mL), followed by voriconazole (34.2%, MIC ≤4 μg/mL). In general, Fusarium species presented MIC values >64 μg/mL for fluconazole, itraconazole and terbinafine. Accurate pathogen identification, characterisation and susceptibility testing provide a better understanding of pathogenesis of Fusarium in onychomycosis.
Introduction: Dermatophytoses are considered a public health problem. The objectives of this study were to determine the evolution of their prevalence in the metropolitan area of Porto Alegre, Brazil, and to analyze the dermatophyte species distribution according to body site and demographic characteristics of the patients. Methodology: This work was a retrospective analysis of data from patients attending a tertiary care hospital during 1996-2011. Results: There were 9,048 cases with cultures positive for dermatophytes. Trichophyton rubrum occurred in 59.6% of the cases, followed by Trichophyton interdigitale (34%), Microsporum canis (2.6%), Epidermophyton floccosum (1.5%), Microsporum gypseum (1.3%), and Trichophyton tonsurans (0.9%). The angular coefficients for T. interdigitale, E. floccosum, T. rubrum, and M. canis were +1.119, +0.211, -0.826 and -0.324% per year, respectively. Males presented higher prevalence of infection (79.3% versus 53.9%). Tinea unguium occurred in 48.5% of the cases, followed by tinea pedis (33.1%). T. rubrum was the predominant species in all regions of the body except the scalp, where M. canis was responsible for 75% of the cases. Conclusion: Monitoring of the evolution of dermatophytosis tracks changes in prevalence over the years and may assist practical measures for the public health control of this disease.
Chromoblastomycosis is a chronic mycosis that affects the skin and subcutaneous tissues caused by several genera of dematiaceous fungi. There is not a treatment of choice. Thus, tools that help guide clinical practice are fundamental. In this sense, antifungal activity tests in vitro could be useful. However, trials with chromoblastomycosis agents are scarce. The aim of this study was to evaluate both the in vitro susceptibility of 60 chromoblastomycosis agents to five antifungals and the combination of amphotericin B (AMB) and terbinafine (TRB). TRB, itraconazole (ITZ) and ketoconazole (KTZ) were, in this order, the drugs which showed better activity against the chromoblastomycosis agents. The less active drugs were voriconazole (VRZ) and AMB. The more differentiated group was Exophiala spinifera. Cladophialophora carrionii and Fonsecaea spp. are significantly more susceptible to KTZ than Phialophora verrucosa, whereas C. carrionii is significantly more sensitive to VRZ than P. verrucosa and E. spinifera. Assays in this direction allow the knowledge of the susceptibility of the causative agents which may help the management of patients with this disease. This study includes the largest number of these agents and of genera found in the literature.
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