European Confederation of Medical Mycology
Confédération Européenne de Mycologie Médicale

In the year 2005, During 11th ECMM Congress (2 TIMM) in Berlin, Germany, Elisabete Ricardo, biochemist and Master Degree student in the Microbiology Laboratory at the School of Medicine in Porto University, Portugal, won the Young Investigator Travel grant for the poster entitled: “Reversion of resistance of Candida due to efflux: a phenotype and genotype study”. In the photo: Elisabete Ricardo (on the right) from Porto University, Portugal, was awarded the 2005 ECMM Young Investigators Travel Award

Elisabete Ricardo. From Mycology Newsletter, 2006, P. 16-17 I’m a biochemist and a Master Degree student in the Microbiology Laboratory at the School of Medicine in Porto University, Portugal. For me it was an enormous surprise and even a great honour to receive the Young Investigators Travel Award for my poster presentation entitled “Reversion of resistance of Candida due to efflux: a phenotype and genotype study” (authors: Cidália Pina-Vaz, Sofia Costa-de-Oliveira, Elisabete Ricardo, Acácio Rodrigues Gonçalves) presented in the 11th Congress of ECMM, 2nd Trends in Medical Mycology, October 2005, Berlin, Germany and also published in a supplement of “Mycoses”. It was my first presenting poster and my first international congress, so the award had a special meaning in my personal life as a beginning researcher. I mostly work with C. albicans, studying gene expression profiles associated with resistance mechanisms involving efflux pumps, one of the main research topic. In our laboratory we also work with all Candida spp, a human fungal pathogen that could cause candidemia in imunocompromised individuals as well as filamentous fungals like Aspergillus spp, its mechanisms of virulence and its susceptibility. Candida species are the most common opportunistic yeasts, especially C. albicans. It causes oral, vaginal and systemic infections with high morbidity. Such infections are associated with immune disorders, endocrine abnormalities and unrestricted use of large spectrum antimicrobians. Candidoses are usually treated with antifungals, being the most widely used the azoles like fluconazole, itraconazole and voriconazole (Smith e Edlind, 2002). There are several mechanisms of azole resistance in C.albicans: reduced accumulation of drugs through active efflux (over expression of genes like CDR1, CDR2 and MDR1), alteration or overexpression of the target enzyme 14– sterol-demethylase, encoded by ERG11, and loss of function downstream mutation in the ergosterol pathway (defective d-5, 6-desaturase encoded by ERG3).Frequent cross-resistance also stresses the need for developing new therapeutic alternatives. I’m focusing my work on the study of CDR1 and CDR2 gene, which belong to the family of ABC transporter genes that encode ATP-dependent efflux pumps, over expressed in many azoles resistant clinical isolates. The primary aim of my research is to determine differences in gene expression profile in clinical isolates of C.albicans clinical isolates, in a central hospital, exhibiting different phenotypes (susceptible and resistant, determined by the Clinical Laboratory Standards Institute, formerly CLSI) and try to understand the molecular mechanism involved. It has already been described in some clinical isolates, with the resistance mechanism associated to efflux, a considerable increase in CDR1 and CDR2 expression, but little is known about how the regulation of expression proceeds and if this is an intrinsic characteristic of the resistant strains or if they acquire it.We just know that resistant strains have over expression of them, so it would be very important to understand what’s going on in the cells. C.albicans genes encode other efflux pumps but these seem to be the most important and prevalent in resistance. Flow cytometry is also used in our laboratory to provide consistent results concerning the susceptibility of Candida to fluconazole in a few hours. Using the fluorescent stain FUN-1, allows classifying Candida strains as susceptible, susceptible dose dependent or resistant to fluconazole. We can even predict the resistance mechanism associated with a certain isolate by blocking efflux pumps and register differences in the fluorescence signal. This technique also helped to clarify the mode of action of some non – antifungals, such as local anaesthetics, sex hormones or ibuprofen as potential blockers for efflux pumps reverting resistance in clinical isolates. Particularly, the results of the awarded poster strongly suggest that ibuprofen, a potent anti-inflammatory and analgesic drug,might have a future role in therapy of candidoses, with association with a classical antifungal drug like fluconazole. I would like to thank Drª Cidália Pina-Vaz and Dr Acácio Rodrigues for the opportunity to work with them and for trusting on me; I would also like to thank all my laboratory colleagues in Microbiology Laboratory for all the support. And off course, to the ECMM group, I congratulate for the magnificent congress in Berlin, where I had the opportunity to talk and mostly learn with so many important researchers, directly or indirectly through the different sessions presented. It was a really enjoyable experience. Thank you so very much for giving me the opportunity to take my work abroad through the Young Investigators Travel Award.