A candidíase tem se tornado uma importante preocupação para a prática clínica, especialmente com o aumento da incidência de pacientes imunocomprometidos. Neste cenário, o desenvolvimento da resistência ao fluconazol se apresenta como um desafio ao tratamento dessas infecções oportunistas. O objetivo deste estudo consistiu em avaliar alguns aspectos epidemiológicos das infecções por Candida em um hospital universitário brasileiro, utilizando dados, anteriormente, indisponíveis. Nós observamos que 44% dos 93 isolados clínicos testados pertenciam à espécie Candida albicans e 56%, a espécies Candidanão-albicans (principalmente Candida tropicalise Candida glabrata). A maioria das cepas foi isolada de amostras de urina, onde C. albicans foi predominantemente detectada. 29 cepas apresentaram um fenótipo de resistência ao fluconazol e destas, 22 foram quimiosensibilizadas pelo FK506, um inibidor clássico dos transportadores ABC, envolvidos na resistência aos azóis. Estes dados sugerem a provável participação das bombas de efluxo nesse fenótipo de resistência. Nosso estudo ressalta a necessidade do desenvolvimento de medidas de controle efetivas para as infecções fúngicas, o uso racional de antifúngicos e o desenvolvimento de novas moléculas capazes de inibir o transporte ativo de antifúngicos.

Candidiasis has become an important concern for clinical practice, especially with the increasing incidence of immunocompromised patients. In this scenario, the development resistance to fluconazole presents a challenge for treating these opportunistic infections. The aim of this study was to evaluate some epidemiology features of Candidainfections in a Brazilian University Hospital using data, previously unavailable. We observed that 44% of the 93 clinical isolates tested, belonged to Candida albicansspecies and 56% belonged to non-Candida albicansspecies (mainly Candida tropicalis and Candida glabrata). Most strains were isolated from urine samples where C. albicans was predominantly detected. 29 strains presented a fluconazole resistance phenotype and of these, 22 were chemosensitised by FK506, a classical inhibitor of ABC transporters related to azoles resistance. These data suggest the probable role of efflux pumps in this resistance phenotype. Our study highlights the need for developing effective control measures for fungal infections, rational use of antifungal drugs and development of new molecules able to abrogate the active transport of antifungals.

Multidrug resistance of cancer cells and pathogenic microorganisms leading to the treatment failure of some forms of cancer or life-threatening bacterial or fungal infections is often caused by the overexpression of multidrug efflux pumps belonging to the ATP-binding cassette transporters superfamily. The multidrug resistance of fungal cells often involves the overexpression of efflux pumps belonging to the pleiotropic drug resistance (PDR) family of ABC transporters. Possibly the best-studied fungal PDR transporter is the multidrug resistance transporter Pdr5p of Saccharomyces cerevisiae. Some research groups have been searching for new inhibitors of these efflux pumps in order to alleviate resistance. Natural products are a great source for the discovery of new compounds with biological activity. Propolis is a complex resinous material collected by honeybees from exudates and buds of certain plant sources and this material is thought to serve as a defense substance for bee hives. Propolis is widely used in traditional medicine and is reported to have a broad spectrum of pharmacological properties. Literature reported some biological functionalities of propolis, such as antibacterial, antiviral, fungicidal, anti-inflammatory and anti-carcinogenic activities. The chemical composition of propolis is qualitatively and quantitatively variable. Components isolated from methanolic extract of red Brazilian propolis (Alagoas, Northeast of Brazil) are isoflavonoids (including pterocarpans, isoflavans, isoflavones), flavanones and polyprenylated benzophenones. In this work we demonstrated the effects of five different isolated compounds on the ATPase activity of Pdr5p. Out of all five substances tested, only BRP-1 was able to completely abolish the enzymatic activity while others worked as positive modulators of the enzyme activity. BRP-1also inhibited the efflux of Rhodamine 6G from yeast cells overexpressing Pdr5p. Taken together, these results demonstrate that Brazilian propolis could be a source of promising compounds that can alleviate the MDR phenomenon, particularly in some fungi, where it could be used as an adjuvant for the treatment with azoles.