XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:70-1

Poster (Painel)

70-1	TRANSCRIPTIONAL PROFILE OF THE HUMAN PATHOGENIC FUNGUS Paracoccidioides brasiliensis IN RESPONSE TO SULFAMETHOXAZOLE
Authors:	Amanda Gregorim Fernandes (UFG - UNIVERSIDADE FEDERAL DE GOIÁS) ; Patrícia Fernanda Zambuzzi Carvalho (UFG - UNIVERSIDADE FEDERAL DE GOIÁS) ; Marize Campos Valadares Bozines (UFG - UNIVERSIDADE FEDERAL DE GOIÁS) ; Célia Maria de Almeida Soares (UFG - UNIVERSIDADE FEDERAL DE GOIÁS) ; Maristela Pereira (UFG - UNIVERSIDADE FEDERAL DE GOIÁS)

Abstract

Paracoccidioidomycosis (PCM) is a systemic fungal infection caused by fungus Paracoccidioides brasiliensis. The fungus is thermo-dimorphic; the mycelial form grows in nature and in vitro at 23º-26ºC. Mycelia and conidia growing as saprophytes in soil, water and plants to room temperature are considered the infective forms of the fungus. The yeast phase occurs at 35º-37ºC in vitro and host tissues. Sulfonamides were the first drugs used for treatment of PCM and continue to be quite active medications nowadays against this fungal infection. It is known that, to bacteria, sulfa drugs are competitive antagonist of &rho-aminobenzoic acid (PABA), which condenses with 2-amino-4-hydroxy-6-hydroxymethyl-7,8 dihydropteridine pyrophosphate (DHPPP) to form dihydropteroate (DHP), a reaction catalyzed by dihydropteroate synthase (DHPS). However, no study was realized to P. brasiliensis. The aim of this work was investigate the global mechanism of action of sulfamethoxazole on P. brasiliensis. Yeast cells were grown on minimum medium in the presence and absence of sulfamethoxazole for 1 and 2 hours, at 36C. After extraction of total RNA, the cDNA was obtained and used to RDA experiments in order to identify the genes up and down regulated. ESTs sequences were clustering using the CAP3 program and classified in agreement with the functions by using BLAT2GO program. Several transcripts related to mitochondrial function were differentially expressed. Among them could be cited transmembrane GTPase, succinate/fumarate mitochondrial transporter, 3-demethylubiquinone-9-methyltransferase, ATP synthase subunit beta, NADPH dehydrogenase, carnitine/acyl carnitine carrier. Other transcripts related to metabolism, and also to unknown functions were up or down regulated. Aiming to validate the RDA and bioinformatics results, we identified genes potentially relevant and validated by real time PCR. Furthermore, to confirm the mitochondrial alteration, it was performed MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The results indicated that sufamethoxazol acts in P. brasiliensis as a competitor for the synthesis of amino acids and nucleic acids and destabilizing mitochondrial functions.਀ Financial Support: CAPES, CNPq, FINEP.

Keyword: Paracoccidioides brasiliensis, sulfamethoxazole, RDA, transcriptome, antifungal

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