ÿþ<HTML><HEAD><TITLE>XI International Meeting on Paracoccidioidomycosis</TITLE><link rel=STYLESHEET type=text/css href=css.css></HEAD><BODY aLink=#ff0000 bgColor=#FFFFFF leftMargin=0 link=#000000 text=#000000 topMargin=0 vLink=#000000 marginheight=0 marginwidth=0><table align=center width=700 cellpadding=0 cellspacing=0><tr><td align=left bgcolor=#cccccc valign=top width=550><font face=arial size=2><strong><font face=Verdana, Arial, Helvetica, sans-serif size=3><font size=1>XI International Meeting on Paracoccidioidomycosis</font></font></strong><font face=Verdana size=1><b><br></b></font><font face=Verdana, Arial,Helvetica, sans-serif size=1><strong> </strong></font></font></td><td align=right bgcolor=#cccccc valign=top width=150><font face=arial size=2><strong><font face=Verdana, Arial, Helvetica, sans-serif size=1><font  size=1>Resume:84-1</font></em></font></strong></font></td></tr><tr><td colspan=2><br><br><table align=center width=700><tr><td><b>Poster (Painel)</b><br><table width="100%"><tr><td width="60">84-1</td><td><b>Antifungal activity of Altenusin isolated from the tropical endophytic fungus Alternaria sp. against clinical fungal strains of Paracoccidioides brasiliensis</b></td></tr><tr><td valign=top>Authors:</td><td><u>Susana Johann </u>  (UFMG - Universidade Federal de Minas GeraisFIOCRUZ - Fundação Oswaldo Cruz) ; Luiz Henrique Rosa   (UFMG - Universidade Federal de Minas Gerais) ; Carlos Augusto Rosa   (UFMG - Universidade Federal de Minas Gerais) ; Pilar Perez   (US - Universidad de Salamanca) ; Patrícia Silva Cisalpino   (UFMG - Universidade Federal de Minas Gerais) ; Betânia Barros Cota   (FIOCRUZ - Fundação Oswaldo Cruz) </td></tr></table><p align=justify><b><font size=2>Abstract</font></b><p align=justify class=tres><font size=2>The pathogenic fungus <i>Paracoccidioides brasiliensis</i> is the etiological agent of paracoccidioidomycosis (PCM), a human systemic mycosis for which the portal of entry of the fungus is via inhalation of airborne propagules into the respiratory tract. Although geographically confined,paracoccidioidomycosis constitutes one of the most prevalent deep mycoses in Central and Southern America region of the world. Antifungal chemotherapy is routinely used in cases of PCM, with initial treatment lasting from 2 to 6 months and involving sulfonamides, amphotericin B, or azoles. This extended period of treatment is necessary due to the significant frequency of relapsing disease.
 Altenusin is a biphenyl derivative isolated from different species of microorganisms, which shows different biological properties. In the present work, we report antifungal activity of altenusin isolated from endophytic fungus <i>Alternaria</i> sp. UFMGCB 55 against clinical isolates of <i>P. brasiliensis</i> as well as its action on cells walls of <i>P. brasiliensis</i> and the model yeast <i>Schizosaccharomyces pombe</i>.
The in vitro antifungal activities of this compound were evaluated using the broth microdilution method against eleven clinical strains of P. brasiliensis and one of S. pombe. The altenusin presented strong activity against <i>P. brasiliensis</i> with MIC range between 1.9 to 30µg/mL and minor activity against <i>S. pombe</i> with MIC value of 62.5µg/ml. The effects of the altenusin on the fungal cell wall were estimated using the sorbitol assay on cells of <i>S. pombe</i>. 
Our results demonstrated that when the medium supplemented with sorbitol was treated with altenusin, the MIC values were higher for <i>P. brasiliensis</i> (Pb18) (MIC value of 62.5µg/ml) and for S. pombe (MIC value of 125 µg/ml). In fluorescence microscopy, using Calcofluor white as stain, the cells of the <i>S. pombe</i> treated with altenusin were more rounded than untreated cell. These findings suggest that altenusin would act through the inhibition of cell wall synthesis or assembly  in both <i>P. brasiliensis</i> and <i>S. pombe</i> and represent an interesting prototype molecule for development of antifungal drugs.
</font></p><br><b>Keyword: </b>&nbsp;Altenusin, Cell wall, Paracoccidiodomycosis</td></tr></table></tr></td></table></body></html>