Sensibilidad in vitro de cepas chilenas de Cryptococcus neoformans de origen clínico / In vitro susceptibility of Chilean Cryptococcus neoformans strains of clinical source

Resumen Introducción: Las infecciones por levaduras del género Cryptococcus afectan principalmente a pacientes con déficit de la inmunidad mediada por células. Han sido escasos los estudios de sensibilidad realizados para este género en Chile. Objetivos: Determinar la sensibilidad in vitro de Cryptococcus sp a antifúngicos de uso habitual y evaluar la concordancia esencial entre sensibilidad determinada por microdilución en caldo y por difusión en agar con tiras comerciales. Materiales y Método: Estudio descriptivo de 21 cepas aisladas desde liquido céfalo-raquídeo y sangre. Las CIM50 y CIM90 para fluconazol, voriconazol y anfotericina B se determinaron por microdilución en caldo (Sensititre Yeast One®) y por difusión en agar con tiras comerciales (MIC Test Strips). Resultados: Todas las cepas correspondieron a C. neoformans. Los rangos de CIM50 y CIM90 para cada antifúngico estudiado fueron amplios por ambos métodos. La concordancia esencial entre microdilución y difusión en agar con tiras comerciales fue de 24, 62 y 29% para fluconazol, voriconazol y anfotericina B, respectivamente. Conclusiones: La prueba de Sensititre Yeast One® y la de difusión en agar con tiras comerciales, MIC Test Strips, tienen una pobre concordancia esencial para fluconazol y anfotericina B.

Abstract Background: Cryptococcus yeast infections primarily affect immunocompromised patients. There have been few susceptibility studies conducted for this genus in Chile. Aims: To determine the in vitro susceptibility to commonly used antifungals and evaluate the concordance between susceptibility determined by microdilution in broth and commercially available strips. Methods: Descriptive study of 21 Cryptococcus strains, isolated from cerebrospinal fluid and blood. The MIC50 and MIC90 for fluconazole, voriconazole and amphotericin B was determined by broth microdilution (Sensititre Yeast One®) and by commercial drug sensitivity strips (MIC Test Strips). Results: All strains corresponded to C. neoformans. The ranges of MIC50 and MIC90 for each antifungal studied were wide by both methods. The essential agreement between Sensititre Yeast One test and strips was 24, 62 and 29% for fluconazole, voriconazole and amphotericin B, respectively. Conclusions: The Sensititre Yeast One test and MIC Test Strips exhibited poor essential concordance, especially for fluconazole and amphotericin B.

Cancer drugs inhibit morphogenesis in the human fungal pathogen, Candida albicans

Candida infections are very common in cancer patients and it is a common practice to prescribe antifungal antibiotics along with anticancer drugs. Yeast to hyphal form switching is considered to be important in invasive candidiasis. Targeting morphogenetic switching may be useful against invasive candidiasis. In this study, we report the antimorphogenetic properties of thirty cancer drugs.

Fusariose em paciente imunocomprometido: sucesso terapêutico com voriconazol / Fusariosis in an immunocompromised patient: therapeutic success with voriconazole

A infecção por Fusarium solani é afecção fúngica potencialmente grave em pacientes imunocomprometidos, sobretudo naqueles portadores de neoplasias hematológicas. A mortalidade é alta,sendo limitadas as opções terapêuticas devido às condições da imunidade do doente e à relativa resistência do fungo aos antifúngicos utilizados de rotina. O voriconazol tem-se mostrado boa alternativa terapêutica em pacientes neutropênicos que apresentam fusariose refratária ou pouco responsiva à anfotericina B. Neste artigo relata-se caso de fusariose em doente imunocomprometido tratado com sucesso com voriconazol.

Fusarium infection is known to be potentially severe in immunocompromised patients, especially those with hematologic malignancies. Mortality rates are high and there are few therapeutic options, due to the severe underlying condition of this group of patients and the relative resistance of Fusarium to conventional antifungal therapy. Voriconazole has been shown to be an effective antifungal agent for neutropenic patients with fusariosis that are refractory or unresponsive to amphotericin B. We report the successful treatment of disseminated Fusarium infection in an immunocompromised host.

Biological Properties of a Polyene Antifungal Substance(AF1) Produced from Streptomyces sp. WCM-9 / 대한의진균학회지

BACKGROUND: Pathogenic fungi infect humans, especially immunocompromised patients, with superficial or deeply invasive pattern. In the past 20 years, fungal infections have been increased dramatically resulted by increment of organ transplantation, cancer, AIDS patients, or use of broad-spectrum antibacterial agents. Fungal infections are now important causes of morbidity and mortality of hospitalized patients. but there is no effective antifungal antibiotics as well as antibacterial antibiotics OBJECTIVE: Effective new antifungal antibiotics are needed for the treatment of mycosis. So in an effort to develop effective antifungal antibiotics, we screened over 600 isolates of Streptomyces sp. from soil. METHODS: Antifungal producing strain was selected using disk diffusion method, An antifungal substance (AF1) was purified with ethyl acetate extraction, silica gel column chromatography and reverse phase HPLC. MICs of AF1 were detected by agar dilition method. RESULTS: The compound showed UV maxima of 307, 321, 340, 359 nm indicating methylpentaene. Minimum inhibitory concentrations of the AF1 were 3.7 microgram/ml against mold, and 3.7 - 7.4 microgram/ml against Candida species. AFI was also active against Crytococcus neoformans, with MIC of 0.9 microgram/ml. The concentration of AF1 for K+ ion release from human red blood cell and hemolysis were 5 microgram/ml. CONCLUSION: The antibiotic purified from culture broth of Streptomyces sp. WCM-9 was a polyene antifungal antibiotic which have broad spectrum antifungal activity.

Isolation,purification and structure determination of antifungal antibiotic FW03-1149 produced by marine Micromonospora sp.FIM03-1149 / 中国海洋药物

Objective To study the antifungal metabolites from marine microorganism FIM03-1149.Methods The producing strain was identified by taxonomical studies.The antifungal compound FW03-1149 was extracted by organic solvents and purified by silica gel column and preparative HPLC from the culture broth of FIM 03-1149.The structure of FW03-1149 was determined by MS data analysis and physico-chemical properties.Results and Conclusion The producing strain was named as Micromonospora sp.FIM03-1149.Compound FW03-1149 was determined to be neorustmicin,showed strong antifungal activities.