Histoplasma capsulatum: ¿un agente emergente para Chile? / Histoplasma capsulatum: an emerging agent in Chile?

Resumen En los últimos 11 meses, nuestro laboratorio ha diagnosticado 9 casos de histoplasmosis de presentación clínica en el territorio nacional. Todos los pacientes asociados a los cuadros clínicos son inmigrantes. Por medio del presente trabajo deseamos difundir y alertar a los profesionales de los laboratorios clínicos de nuestro país de la presencia y circulación de cepas de Histoplasma capsulatum en muestras clínicas. Asimismo, deseamos concientizar en el reforzamiento de las medidas de bioseguridad al interior de los laboratorios clínicos.

In the last eleven months, we have diagnosed 9 cases of Histoplasmosis in our country. All patients affected were from endemic areas of South-America. Here, we wish to inform and prevent to all clinical laboratories from Chile about the presence of Histoplasma capsulatum in clinical samples. In the same way we want to prepare and raising awareness of the strengthening of biosecurity measures.

Terpinen-4-ol, tyrosol, and ß-lapachone as potential antifungals against dimorphic fungi

Abstract This study aimed to evaluate the in vitro antifungal activity of terpinen-4-ol, tyrosol, and β-lapachone against strains of Coccidioides posadasii in filamentous phase (n = 22) and Histoplasma capsulatum in both filamentous (n = 40) and yeast phases (n = 13), using the broth dilution methods as described by the Clinical and Laboratory Standards Institute, to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of these compounds. The mechanisms of action of these compounds were also investigated by analyzing their effect on cell membrane permeability and ergosterol synthesis. The MIC and MFCf these compounds against C. posadasii, mycelial H. capsulatum, and yeast-like H. capsulatum, were in the following ranges: 350-5720 µg/mL, 20-2860 µg/mL, and 40-1420 µg/mL, respectively for terpinen-4-ol; 250-4000 µg/mL, 30-2000 µg/mL, and 10-1000 µg/mL, respectively, for tyrosol; and 0.48-7.8 µg/mL, 0.25-16 µg/mL, and 0.125-4 µg/mL, respectively for β-lapachone. These compounds showed a decrease in MIC when the samples were subjected to osmotic stress, suggesting that the compounds acted on the fungal membrane. All the compounds were able to reduce the ergosterol content of the fungal strains. Finally, tyrosol was able to cause a leakage of intracellular molecules.

Pulmonary blastomycosis on autopsy: a rare case report.

A case of pulmonary blastomycosis on autopsy in a middle aged male from rural background is presented herewith. Blastomycosis is a pyogranulomatous disease caused by the dimorphic fungus blastomyces dermatitidis. Blastomycosis is endemic in regions of North America that border the Great Lakes. It is one of the great mimickers in medicine. Pulmonary blastomycosis has a broad range of clinical presentations, varying from completely asymptomatic pulmonary infiltrates to diffuse and massive parenchymal involvement that can lead to Acute Respiratory Distress Syndrome (ARDS). Human infection occurs when soil containing microfoci of mycelia is distributed and airborne conidia are inhaled. If natural defences in the alveoli fail to contain the infection, lymphohematogenous dissemination ensues. Diagnosis is based on culture and direct visualization of round, multinucleated yeast forms that produce daughter cells from a single broad- based bud. Most of the cases of blastomycosis reported in India are imported from the endemic areas of the World except a few authochthonous cases in North India.