ABSTRACT
BACKGROUND: The treatment of paracoccidioidomycosis (PCM) is a challenge, and the discovery of new antifungal compounds is crucial. The phenacylideneoxindoles exhibited promising antifungal activity against Paracoccidioides spp., but their mode of action remains unknown. METHODS: Through proteomic analysis, we investigated the effects of (E)-3-(2-oxo-2-phenylethylidene)indolin-2-one on P. brasiliensis. In addition, we investigated the metabolic alterations of P. brasiliensis in response to the compound. Furthermore, the effects of the compound on the membrane, ethanol production, and reactive oxygen species (ROS) production were verified. RESULTS: We identified differentially regulated proteins that revealed significant metabolic reorganization, including an increase in ethanol production, suggesting the activation of alcoholic fermentation and alterations in the rigidity of fungal cell membrane with an increase of the ergosterol content and formation of ROS. CONCLUSIONS: These findings enhance our understanding of the mode of action and response of P. brasiliensis to the investigated promising antifungal compound, emphasizing its potential as a candidate for the treatment of PCM.
ABSTRACT
BACKGROUND: Paracoccidioidomycosis is a systemic mycosis caused by the inhalation of conidia of the genus Paracoccidioides. During the infectious process, fungal cells use several carbon sources, leading to the production of propionyl-CoA. The latter is metabolized by the methylcitrate synthase, a key enzyme of the methylcitrate cycle. We identified an inhibitor compound (ZINC08964784) that showed antifungal activity against P. brasiliensis. METHODS: This work aimed to understand the fungal metabolic response of P. brasiliensis cells exposed to ZINC08964784 through a proteomics approach. We used a glucose-free medium supplemented with propionate in order to simulate the environment found by the pathogen during the infection. We performed pyruvate dosage, proteolytic assay, dosage of intracellular lipids and quantification of reactive oxygen species in order to validate the proteomic results. RESULTS: The proteomic analysis indicated that the fungal cells undergo a metabolic shift due to the inhibition of the methylcitrate cycle and the generation of reactive species. Proteolytic enzymes were induced, driving amino acids into degradation for energy production. In addition, glycolysis and the citric acid cycle were down-regulated while ß-oxidation was up-regulated. The accumulation of pyruvate and propionyl-CoA led the cells to a state of oxidative stress in the presence of ZINC08964784. CONCLUSIONS: The inhibition of methylcitrate synthase caused by the compound promoted a metabolic shift in P. brasiliensis damaging energy production and generating oxidative stress. Hence, the compound is a promising alternative for developing new strategies of therapies against paracoccidioidomycosis.
ABSTRACT
Paracoccidioidomycosis is a neglected disease that causes economic and social impacts, mainly affecting people of certain social segments, such as rural workers. The limitations of antifungals, such as toxicity, drug interactions, restricted routes of administration, and the reduced bioavailability in target tissues, have become evident in clinical settings. These factors, added to the fact that Paracoccidioidomycosis (PCM) therapy is a long process, lasting from months to years, emphasize the need for the research and development of new molecules. Researchers have concentrated efforts on the identification of new compounds using numerous tools and targeting important proteins from Paracoccidioides, with the emphasis on enzymatic pathways absent in humans. This review aims to discuss the aspects related to the identification of compounds, methodologies, and perspectives when proposing new antifungal agents against PCM.
ABSTRACT
Introduction: The term candiduria refers to the presence of yeast in urine and Candida albicans is the most common agent. In general, routine laboratories do not perform identification and cultivation of yeast. Objectives: To determine the prevalence of Candida species and to evaluate the antifungal susceptibility of the species isolated in urine of outpatients Jataí-GO, between January-October 2013. Material and method: Urine samples containing fungal structures were plated out on Sabouraud agar with chloramphenicol. Differentiation was taken with the urease test, nitrogen and carbon sources assimilation, germ tube test, morphology on cornmeal agar and chromogenic agar cultivation. Susceptibility was evaluated at antifungal itraconazole, fluconazole, amphotericin B and ketoconazole. Results: 1,215 urine tests were performed, and 64 had fungal structures (5.3%). Two samples were lost, thus here we considered 62 isolates. From this total, 43 were identified as C. albicans (67.2 %), eight C. glabrata (12.5 %), five C. krusei (7.8%), three C. tropicalis (4.7%), and three could not determine the species (4.7%). Amphotericin B and ketoconazole inhibited 94.9% of the isolates. On the other hand, 55.9% and 54.2 % were resistant to itraconazole and fluconazole, respectively. The resistance rates of both fluconazole and itraconazole for C. glabrata and C. albicans, as fluconazole for C. albicans and C. krusei, showed significant differences (p < 0.05). Conclusion: These data demonstrate the importance of conducting a full identification and susceptibility to antifungal agents in samples with yeast infection...
Introdução: O termo candidúria designa a presença de leveduras na urina e Candida albicans é o agente mais comum. Em geral, os laboratórios de rotina não realizam o cultivo e a identificação da levedura. Objetivos: Determinar a prevalência de espécies de Candida e avaliar o perfil de sensibilidade aos antifúngicos das espécies isoladas em urina de pacientes ambulatoriais do município de Jataí-GO, entre janeiro e outubro de 2013. Material e método: Amostras de urina que continham estruturas fúngicas foram semeadas em ágar Sabouraud com cloranfenicol. A diferenciação foi feita com provas da urease, assimilação de fontes de nitrogênio e carbono, tubo germinativo, morfologia em ágar fubá e cultivo em ágar cromogênico. Foi avaliada a sensibilidade aos antifúngicos itraconazol, fluconazol, anfotericina B e cetoconazol. Resultados: Foram realizados 1.215 exames de urina, sendo que 64 apresentaram estruturas fúngicas (5,3%). Houve perda de duas amostras, assim, considerou-se 62 isolados. Desse total, 43 foram identificadas como C. albicans (67,2%); oito, C. glabrata (12,5%); cinco, C. krusei (7,8%); três, C. tropicalis (4,7%); e em três não foi possível determinar a espécie (4,7%). Anfotericina B e cetoconazol inibiram 94,9% dos isolados. Por outro lado, 55,9% e 54,2%, respectivamente, apresentaram resistência a itraconazol e fluconazol. As taxas de resistência a itraconazol e fluconazol de C. glabrata e C. albicans e também do fluconazol entre C. albicans e C. krusei apresentaram diferenças significativas (p < 0,05). Conclusão: Os dados demonstram a importância de se realizar a identificação completa e também o antifungigrama para amostras que apresentam infecção por leveduras...
