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

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.

Synthesis and in vitro antifungal activity of isoniazid-derived hydrazones against Coccidioides posadasii.

Coccidioidomycosis is a potentially severe infection caused by dimorphic fungi Coccidioides immitis and Coccidioides posadasii. Although guidelines are well established, refractory disease is a matter of concern in the clinical management of coccidioidomycosis. In the present study three isoniazid-derived hydrazones N'-[(E)-1-(4-methoxyphenyl)ethylidene]pyridine-4-carbohydrazide, N'-[(E)-1-(4-methylphenyl)ethylidene]pyridine-4-carbohydrazide, and N'-[(E)-1-(phenyl)ethylidene]pyridine-4-carbohydrazide were synthesized and evaluated for antifungal activity against C.

Inhibition of heat-shock protein 90 enhances the susceptibility to antifungals and reduces the virulence of Cryptococcus neoformans/Cryptococcus gattii species complex.

Heat-shock proteins (Hsps) are chaperones required for the maintenance of cellular homeostasis in different fungal pathogens, playing an important role in the infectious process. This study investigated the effect of pharmacological inhibition of Hsp90 by radicicol on the Cryptococcus neoformans/Cryptococcus gattii species complex--agents of the most common life-threatening fungal infection amongst immunocompromised patients. The influence of Hsp90 inhibition was investigated regarding in vitro susceptibility to antifungal agents of planktonic and sessile cells, ergosterol concentration, cell membrane integrity, growth at 37 °C, production of virulence factors in vitro, and experimental infection in Caenorhabditis elegans.

Inhibitory activity of isoniazid and ethionamide against Cryptococcus biofilms.

In recent years, the search for drugs to treat systemic and opportunistic mycoses has attracted great interest from the scientific community. This study evaluated the in vitro inhibitory effect of the antituberculosis drugs isoniazid and ethionamide alone and combined with itraconazole and fluconazole against biofilms of Cryptococcus neoformans and Cryptococcus gattii. Antimicrobials were tested at defined concentrations after susceptibility assays with Cryptococcus planktonic cells.

Trichosporon inkin biofilms produce extracellular proteases and exhibit resistance to antifungals.

The aim of this study was to determine experimental conditions for in vitro biofilm formation of clinical isolates of Trichosporon inkin, an important opportunistic pathogen in immunocompromised patients. Biofilms were formed in microtitre plates in three different media (RPMI, Sabouraud and CLED), with inocula of 104, 105 or 106 cells ml- 1, at pH 5.5 and 7.

Histoplasma capsulatum in planktonic and biofilm forms: in vitro susceptibility to amphotericin B, itraconazole and farnesol.

It is believed that most microbial infections are caused by pathogens organized in biofilms. Recently, it was shown that the dimorphic fungus Histoplasma capsulatum, estimated to be the most common cause of fungal respiratory diseases, is also able to form biofilm. Although the antifungal therapy commonly used is effective, refractory cases and recurrences have been reported.

Candida tropicalis isolates obtained from veterinary sources show resistance to azoles and produce virulence factors.

Candida tropicalis has been associated with invasive candidiasis, being the first or second most common non-Candida albicans Candida species isolated in humans with candidemia and candiduria, as well as being frequently isolated from healthy animals. This study aimed to characterize C. tropicalis isolates (n = 64) obtained from several animal species regarding antifungal susceptibility and production of virulence factors.

In vitro inhibitory activity of terpenic derivatives against clinical and environmental strains of the Sporothrix schenkii complex.

Sporotrichosis is a subacute or chronic subcutaneous infection, caused by the fungus Sporothrix schenkii complex, occurring in human and animal tissues. Potassium iodide and itraconazole have been used as effective therapy for first-choice treatment, while amphotericin B may be indicated for disseminated infection. However, the adverse effects of potassium iodide and amphotericin B or the long duration of therapy with itraconazole often weigh against their use, leading to the search for alternatives for the treatment of severe infections.

The calcineurin inhibitor cyclosporin A exhibits synergism with antifungals against Candida parapsilosis species complex.

Candida parapsilosis complex comprises three closely related species, C. parapsilosis sensu stricto, Candida metapsilosis and Candida orthopsilosis. In the last decade, antifungal resistance to azoles and caspofungin among C.

In vitro inhibitory effect of miltefosine against strains of Histoplasma capsulatum var. capsulatum and Sporothrix spp.

Miltefosine (MIL), originally developed for use in cancer chemotherapy, has been shown to have important antifungal activity against several pathogenic fungi. Our aim in this study was to determine the in vitro activity of MIL against the dimorphic fungi Histoplasma capsulatum and Sporothrix spp. This was done using the broth microdilution method.

Synthesis and antifungal activity in vitro of isoniazid derivatives against histoplasma capsulatum var. capsulatum.

Histoplasmosis is a severe infection that affects millions of patients worldwide and is endemic in the Americas. Amphotericin B (AMB) and itraconazole are highly effective for the treatment of severe and milder forms of the disease, but AMB is toxic, and the bioavailability of itraconazole is erratic. Therefore, it is important to investigate new classes of drugs for histoplasmosis treatment.

Antigens of Coccidioides posadasii as an important tool for the immunodiagnosis of coccidioidomycosis.

Serologic diagnosis has been presented as a safe alternative for coccidioidomycosis. However, commercial kits based on coccidioidal antibodies available in the USA are considered too expensive for laboratories outside that country. In this study, we describe the preparation of antigens for detection of human coccidioidal antibodies by the immunodiffusion test (ID) and enzyme immunoassay (EIA).

Coccidioides posadasii infection in bats, Brazil.

To analyze the eco-epidemiologic aspects of Histoplasma capsulatum in Brazil, we tested 83 bats for this fungus. Although H. capsulatum was not isolated, Coccidioides posadasii was recovered from Carollia perspicillata bat lungs.

Cotrimoxazole enhances the in vitro susceptibility of Coccidioides posadasii to antifungals.

The aim of the present study was to evaluate the effect of cotrimoxazole on the in vitro susceptibility of Coccidioides posadasii strains to antifungals. A total of 18 strains of C. posadasii isolated in Brazil were evaluated in this study.

Synergistic effect of antituberculosis drugs and azoles in vitro against Histoplasma capsulatum var. capsulatum.

This study evaluated in vitro interactions of antituberculosis drugs and triazoles against Histoplasma capsulatum. Nine drug combinations, each including an antituberculosis drug (isoniazid, pyrazinamide, or ethambutol) plus a triazole (itraconazole, fluconazole, or voriconazole), were tested against both growth forms of H. capsulatum.