R S N Brilhante1,2, E P Caetano1, R A C Lima1, D S C M Castelo Branco1, R Serpa1, J S Oliveira1, A J Monteiro3, M F G Rocha1,4, R A Cordeiro1,2, J J C Sidrim1,2. 1. Specialized Medical Mycology Center, Postgraduate Program in Medical Microbiology, Federal University of Ceará, Fortaleza, CE, Brazil. 2. Postgraduate Program in Medical Sciences, Federal University of Ceará, Fortaleza, CE, Brazil. 3. Department of Statistics and Applied Mathematics, Federal University of Ceará, Fortaleza, CE, Brazil. 4. Postgraduate Program in Veterinary Sciences, State University of Ceará, Fortaleza, CE, Brazil.
Abstract
AIMS: This study aimed to evaluate the in vitro activity of miltefosine and levamisole against strains of Coccidioides posadasii in the filamentous phase and strains of Histoplasma capsulatum in filamentous and yeast phases. METHODS AND RESULTS: Strains of C. posadasii in the filamentous phase (n = 22) and strains of H. capsulatum in filamentous (n = 40) and yeast phases (n = 13) were, respectively, submitted to broth macrodilution and broth microdilution methods, as described by the Clinical and Laboratory Standards Institute, to determine the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of miltefosine and levamisole. The effect of the drugs on cell membrane permeability under osmotic stress conditions and total ergosterol production were also assessed, along with quantification of extravasated molecules. The results show the inhibitory effect of levamisole and miltefosine against C. posadasii and H. capsulatum and the effect of these drugs on ergosterol synthesis and the permeability of the plasma membrane using subinhibitory concentrations against strains subjected to osmotic stress. Levamisole was also able to cause the release of nucleic acids. CONCLUSIONS: Miltefosine and levamisole are capable of inhibiting the in vitro growth of C. posadasii and H. capsulatum, probably by altering the permeability of the cellular membrane. SIGNIFICANCE AND IMPACT OF THE STUDY: This work presents alternatives for the treatment of histoplasmosis and coccidioidomycosis, raising the possibility of the use of miltefosine and levamisole as adjuvants in antifungal therapy, providing perspectives for the design of in vivo studies.
AIMS: This study aimed to evaluate the in vitro activity of miltefosine and levamisole against strains of Coccidioides posadasii in the filamentous phase and strains of Histoplasma capsulatum in filamentous and yeast phases. METHODS AND RESULTS: Strains of C. posadasii in the filamentous phase (n = 22) and strains of H. capsulatum in filamentous (n = 40) and yeast phases (n = 13) were, respectively, submitted to broth macrodilution and broth microdilution methods, as described by the Clinical and Laboratory Standards Institute, to determine the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) of miltefosine and levamisole. The effect of the drugs on cell membrane permeability under osmotic stress conditions and total ergosterol production were also assessed, along with quantification of extravasated molecules. The results show the inhibitory effect of levamisole and miltefosine against C. posadasii and H. capsulatum and the effect of these drugs on ergosterol synthesis and the permeability of the plasma membrane using subinhibitory concentrations against strains subjected to osmotic stress. Levamisole was also able to cause the release of nucleic acids. CONCLUSIONS:Miltefosine and levamisole are capable of inhibiting the in vitro growth of C. posadasii and H. capsulatum, probably by altering the permeability of the cellular membrane. SIGNIFICANCE AND IMPACT OF THE STUDY: This work presents alternatives for the treatment of histoplasmosis and coccidioidomycosis, raising the possibility of the use of miltefosine and levamisole as adjuvants in antifungal therapy, providing perspectives for the design of in vivo studies.
Authors: Erico S Loreto; Juliana S M Tondolo; Daniele C Oliveira; Janio M Santurio; Sydney H Alves Journal: Antimicrob Agents Chemother Date: 2018-02-23 Impact factor: 5.191
Authors: Patricia Akemi Assato; Julhiany de Fátima da Silva; Haroldo Cesar de Oliveira; Caroline Maria Marcos; Danuza Rossi; Sandro Roberto Valentini; Maria José Soares Mendes-Giannini; Cleslei Fernando Zanelli; Ana Marisa Fusco-Almeida Journal: BMC Microbiol Date: 2015-11-04 Impact factor: 3.605