ABSTRACT
BACKGROUND: Dermatophytoses affect more than 20% of the world's population and is caused by filamentous fungi, mainly of the genus Trichophyton. The species identification through microscopic direct examination and culture methods is challenging, with molecular presenting high sensitivity and specificity. Although there are several therapy options for dermatophyte infections, treatment failures and antifungal resistance are growing concerns. OBJECTIVE: This study aimed to identify clinical isolates of Trichophyton spp. from southern Brazil using molecular methods and determine their in-vitro antifungal susceptibility. MATERIAL AND METHODS: Seventy-five isolates were identified through sequencing of the ITS region. The exposure to seven antifungals drugs was performed according to protocol M28-A2 of the Clinical and Laboratory Standards Institute (CLSI). RESULTS: Sixty-one isolates (81%) were identified as T. interdigitale, which differs from the epidemiological data present in the literature. Thirteen isolates were identified as T. rubrum and one as T. tonsurans. Terbinafine was the most effective antifungal, followed by itraconazole and voriconazole, which is in accordance with the results reported in previous studies. CONCLUSIONS: The use of molecular methods to identify Trichophyton spp. clinical isolates and the performance of susceptibility tests are relevant to epidemiological data, identification of the emergence of antifungal resistance, and to help to translate the in-vitro antifungal susceptibility results into clinical practice.
Subject(s)
Arthrodermataceae , Trichophyton , Antifungal Agents/pharmacology , Brazil , Microbial Sensitivity Tests , Terbinafine , Trichophyton/geneticsABSTRACT
We evaluated the growth and the susceptibility to oxidative stress of Sporothrix spp., exposed to different iron concentrations in culture medium, and the susceptibility of Sporothrix spp. to itraconazole, alone and in combination with to the iron chelator deferasirox. The results showed that the growth of S. brasiliensis isolates was more affected by iron availability in comparison to S. schenckii, but both fungal species conidia became more prone to oxidative stress when iron was added to culture medium. Conversely, the combination of itraconazole and deferasirox only resulted in synergism against a minority of S. schenckii isolates.
Subject(s)
Antifungal Agents/pharmacology , Iron/pharmacology , Itraconazole/pharmacology , Sporothrix/drug effects , Sporothrix/growth & development , Culture Media/chemistry , Deferasirox/pharmacology , Drug Synergism , Iron/metabolism , Microbial Sensitivity Tests , Spores, Fungal/drug effects , Sporothrix/metabolism , Sporotrichosis/drug therapy , Sporotrichosis/microbiologyABSTRACT
We report a case of a 56-year-old Brazilian woman, with relapsing lepromatous leprosy, and onychomycosis caused by a non-dermatophyte filamentous fungi. The pathogenic fungi was identified as Arthrinium arundinis and treated with chemical abrasion of the nail with 40% urea and application of terbinafine cream. Onychomycosis caused by Arthrinium species is rare, and this is the second reported case.
ABSTRACT
We report a case of phaeohyphomycosis that affected the leg of a 45-year-old Brazilian man, car mechanic and renal transplanted. The direct mycological examination evidenced dematiaceous septated hyphae. The pathogenic fungal species was identified as Exophiala xenobiotica. Antifungal activity in vitro revealed terbinafine as the best antifungal. For treatment, it was chosen surgical excision of the entire lesion and used systemic itraconazole. Phaeohyphomycosis caused by Exophiala xenobiotica is extremely rare and is closely related to transplant patients.
ABSTRACT
Chromoblastomycosis (CBM) is a chronic cutaneous and subcutaneous infection caused by melanized fungal species. We quantified the extractable melanin of 77 strains of CBM agents distributed within five genera. Moreover, resistance to oxidative stress was evaluated in strains exposed or not to the melanin inhibitor tricyclazole. The median percentage of melanin mass extracted from dry fungal mass varied from 0.69 (Rhinocladiella similis) to 3.81 (Phialophora americana). Inhibition of melanin synthesis decreased survival rates to hydrogen peroxide. Together, these data highlight the importance of melanin in CBM agents.
Subject(s)
Ascomycota/chemistry , Ascomycota/physiology , Chromoblastomycosis/microbiology , Melanins/analysis , Oxidative Stress , Antifungal Agents/pharmacology , Ascomycota/drug effects , Ascomycota/isolation & purification , Humans , Hydrogen Peroxide/pharmacology , Melanins/biosynthesis , Microbial Viability/drug effects , Oxidative Stress/drug effects , Phialophora/chemistry , Phialophora/drug effects , Phialophora/isolation & purification , Phialophora/physiology , Species Specificity , Spores, Fungal/physiology , Thiazoles/pharmacologyABSTRACT
We report a case of a patient with lymphocutaneous sporotrichosis in the right upper limb. The fungus was identified as Sporothrix schenckii senso stricto by calmodulin gene sequencing. The initial treatment was itraconazole (200 mg/day), but in vitro antifungal susceptibility demonstrated high resistant to this and another six antifungals, with exception to terbinafine. The lesions did not regress with itraconazole treatment. Thus, 500 mg/day of terbinafine was prescribed and clinical cure was obtained after four months.
ABSTRACT
O gênero Acanthamoeba pertencente ao grupo das amebas de vida livre e é amplamente distribuído no ambiente. Estes protistas são conhecidos por causarem doenças graves, como a Encefalite Amebiana Granulomatosa em pacientes imunocomprometidos e ceratite amebiana, especialmente em usuários de lentes de contato imunocompetentes. Própolis verde é uma substância resinosa e balsâmica, conhecida na medicina alternativa por exibir várias atividades biológicas. Neste estudo avaliou-se a atividade amebicida de um extrato aquoso de própolis verde contra trofozoítos e cistos de A. castellanii. Nas concentrações de 10 e 20 mg/mL, o extrato foi capaz de inativar 100% de trofozoítos no prazo de 24 horas e 48 horas, enquanto a uma concentração de 5 mg/mL 100% dos trofozoítos foram inativados em 72 horas. Os cistos foram inativados após 24 horas de exposição ao extrato à concentração de 40 mg/mL. O efeito do extrato foi avaliado sobre células HCE (epiteliais de córnea humana), empregando-se ensaio de viabilidade baseado na redução do sal de tetrazólio MTT. O extrato não apresentou efeito citotóxico significativo sobre as células HCE, nas concentrações de 0,312, 0,625, 1,25 e 2,5 mg/mL. O teste de adesão realizado mostrou que a fixação de Acanthamoeba a células HCE apresenta comportamento dose- dependente em relação ao extrato de própolis. Assim, este estudo demonstrou a eficácia da própolis verde contra trofozoítos e cistos de Acanthamoeba e provou ser uma substância promissora especialmente para a formulação de soluções para desinfecção de superfícies. No entanto, mais estudos são necessários para entender seu mecanismo de ação.
