Arlete Emily Cury

Susceptibility of sequential Fonsecaea pedrosoi isolates from chromoblastomycosis patients to antifungal agents

Fourteen Fonsecaea pedrosoi isolates from six chromoblastomycosis patients were submitted to susceptibility testing. Some patients were undergoing treatment with itraconazole (ITZ) and/or cryosurgery with liquid nitrogen. The antifungal agents amphotericin B (AMB), ITZ, fluconazole (FCZ), ketoconazole (KCZ), 5‐fluorocytosine (5‐FC), and terbinafine (TBF) were tested. AMB and FCZ showed less activity for all isolates. The most active agents were KCZ and TBF. Sequentially isolates from four patients presented ITZ minimal inhibitory concentration (MIC) higher than the previous ones; for two of these patients, response to therapy with this agent was not observed. These results suggest development of microbiologic resistance to ITZ in four instances, two of them coinciding with lack of clinical response to this drug.

Yeasts from the oral cavity of children with AIDS: exoenzyme production and antifungal resistance

The oral fungal microbiota of 30 children with AIDS, of both genders, aged from two to six years, receiving outpatient treatment, was evaluated and compared with that of a control group composed of 30 healthy subjects with matching ages and genders. Virulence factors, such as exoenzyme production, and susceptibility to five antifungal agents using an E-Test kit were evaluated. C. albicans predominated over other species in the AIDS group, showing a higher production of proteinase and phospholipase when compared with that observed in the control group. In this study few clinical manifestations of and low selectivity for C. albicans (23.3%) were observed in the AIDS group. The enzymatic studies showed that 53.8% of the AIDS strains were strongly positive whereas only 33.3% of the non-AIDS strains were positive. Amphotericin B was the most effective drug among the antifungal agents tested against C. albicans. The frequency, selectivity and level of exoenzyme production by C. albicans suggest a higher pathogenicity in the AIDS children than in the control children.

Suscetibilidade a antifungicos de cepas de Candida albicans isoladas de pacientes com estomatite protetica

Users of total prosthesis present in general a high frequency of the so called denture stomatitis, associated to erythematous candidiasis. So, we evaluated the susceptibility of oral yeast to three antifungal agents. Strains of Candida albicans isolated from patients with denture stomatitis were evaluated in relation to the susceptibility of the antifungal drugs as amphotericin B (polyenic derivatives), and azole agents as ketoconazole and miconazole. The antifungal activity was evaluated, and the minimal inhibitory concentration (MIC) and minimal fungicide concentration (MFC) were determined utilizing the agar dilution method. The results demonstrated low values for MICs and MFCs (0.15 mg/ml) for AmB in face of all yeast present. For miconazole and ketoconazole, MICs were invariably £ 4.00 mg/ml, while values of the MFC were ³ 16.00 mg/ml for the majority of the strains. We could conclude that AmB presented a major fungicidal action in vitro, while azoles demonstrated a fungistatic but not fungicidal profile. So, we can consider that new drugs, mainly topical ones, are needed to treat lesions related to denture stomatitis, so commonly observed in wearers of dental prostheses.

Antifungal susceptibility of Candida albicans isolated from oral mucosa of patients with cancer

O crescente numero de infeccoes fungicas bucais em pacientes imunocomprometidos tem estimulado a pesquisa de drogas mais eficientes. Procuramos, assim, avaliar a suscetibilidade in vitro de cepas de Candida albicans de pacientes com câncer submetidos ou nao a radioterapia frente as seguintes drogas: anfotericina B, cetoconazol, miconazol e itraconazol. A tecnica de diluicao em agar YNB e o subcultivo em AS foram respectivamente utilizados para determinacao da CIM (Concentracao Inibitoria Minima) e da CFM (Concentracao Fungicida Minima). Com esta metodologia, a droga que mostrou melhor atividade antifungica para cepas de C. albicans isoladas de qualquer dos grupos de pacientes foi a anfotericina B, apresentando baixos valores de CIM em comparacao aos azois, e de CFM. Contudo, e necessario lembrar que o tratamento com antibioticos polienicos pode causar efeitos toxicos, mesmo em doses necessarias para se atingir bons resultados com os antifungicos. A coexistencia de outras especies nesses pacientes, principalmente entre os submetidos a radioterapia, as condicoes locais, bem como o uso de outras drogas, devem ser tambem considerados. Acredita-se, porem, que o uso adequado dos antifungicos atuais e a disponibilidade de novas drogas que nao produzam consequencias indesejaveis possam conduzir a melhores resultados na clinica diaria.

Studies on components of the chloroform-methanol extract from Madurella grisea

Some of the lipids described in many fungi were found in Madurella grisea, in addition to other diethyl ether-soluble components with peculiar characteristics. One fraction structurally related to ethane diol (ethylene glycol) accounted for about 41% and a compound identified as methyl terephthalate represented about 38% of the extract. No steroids were detected. The absence of these lipids may perhaps explain the resistance of this organism to polyene antibiotics.