<p>&nbsp / </p> <p align="left">One of the most common HIV-associated opportunistic infections is candidiasis, caused by <i><font face="TimesNewRoman,Italic">Candida albicans </font></i><font lang="KO" face="TimesNewRoman">or other </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species. In immune suppressed subjects, this commensal organism can cause an increase in patient morbidity and mortality due to oropharyngeal or systemic dissemination. Limited information exists on the prevalence and antifungal susceptibility of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species in the African continent, the most HIV-affected region globally and home to new and emerging drug resistant </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species. The mechanisms of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">drug resistance in the African continent have also not been described. In this study, 255 </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species isolated from the oral mucosa of HIV-positive South African and Cameroonian patients were identified using differential and chromogenic media and their drug susceptibility profiles tested using the disk diffusion method and the TREK Sensititre system, an automated broth microdilution method. </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">cell wall fractions were run on SDSPAGE and HPLC-MS with the aim of identifying peptides specifically expressed by antifungal drug resistant isolates. Comparisons between the two groups of isolates revealed differences in </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species prevalence and drug susceptibility with interesting associations observed between specific drug resistance and duration of ARV therapy. This study showed that fluconazole, the drug of choice for the treatment of candidiasis in the African continent, is not an effective therapy for most cases of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">infection, and suggests that regional surveillance be implemented in the continent. A multiple-drug resistant </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">strain was identified in this study, a finding that has not previously been documented. The use of proteomics tools allowed for the identification of peptides involved in drug resistance and the elucidation of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">colonization mechanisms in HIV-infected African patients.</font></i></i></i></i></i></i></i></i></i></i></p>

<p>&nbsp / </p> <p align="left">One of the most common HIV-associated opportunistic infections is candidiasis, caused by <i><font face="TimesNewRoman,Italic">Candida albicans </font></i><font lang="KO" face="TimesNewRoman">or other </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species. In immune suppressed subjects, this commensal organism can cause an increase in patient morbidity and mortality due to oropharyngeal or systemic dissemination. Limited information exists on the prevalence and antifungal susceptibility of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species in the African continent, the most HIV-affected region globally and home to new and emerging drug resistant </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species. The mechanisms of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">drug resistance in the African continent have also not been described. In this study, 255 </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species isolated from the oral mucosa of HIV-positive South African and Cameroonian patients were identified using differential and chromogenic media and their drug susceptibility profiles tested using the disk diffusion method and the TREK Sensititre system, an automated broth microdilution method. </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">cell wall fractions were run on SDSPAGE and HPLC-MS with the aim of identifying peptides specifically expressed by antifungal drug resistant isolates. Comparisons between the two groups of isolates revealed differences in </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">species prevalence and drug susceptibility with interesting associations observed between specific drug resistance and duration of ARV therapy. This study showed that fluconazole, the drug of choice for the treatment of candidiasis in the African continent, is not an effective therapy for most cases of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">infection, and suggests that regional surveillance be implemented in the continent. A multiple-drug resistant </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">strain was identified in this study, a finding that has not previously been documented. The use of proteomics tools allowed for the identification of peptides involved in drug resistance and the elucidation of </font><i><font face="TimesNewRoman,Italic">Candida </font><font lang="KO" face="TimesNewRoman">colonization mechanisms in HIV-infected African patients.</font></i></i></i></i></i></i></i></i></i></i></p>

Philosophiae Doctor - PhD / One of the most common HIV-associated opportunistic infections is candidiasis, caused by Candida albicans or other Candida species. In immune suppressed subjects, this commensal organism can cause an increase in patient morbidity and mortality due to oropharyngeal or systemic dissemination. Limited information exists on the prevalence and antifungal susceptibility of Candida species in the African continent, the most HIV-affected region globally and home to new and emerging drug resistant Candida species. The mechanisms of Candida drug resistance in the African continent have also not been described. In this study, 255 Candida species isolated from the oral mucosa of HIV-positive South African and Cameroonian patients were identified using differential and chromogenic media and their drug susceptibility profiles tested using the disk diffusion method and the TREK Sensititre system, an automated broth microdilution method. Candida cell wall fractions were run on SDSPAGE and HPLC-MS with the aim of identifying peptides specifically expressed by antifungal drug resistant isolates. Comparisons between the two groups of isolates revealed differences in Candida species prevalence and drug susceptibility with interesting associations observed between specific drug resistance and duration of ARV therapy. This study showed that fluconazole, the drug of choice for the treatment of candidiasis in the African continent, is not an effective therapy for most cases of Candida infection, and suggests that regional surveillance be implemented in the continent. A multiple-drug resistant Candida strain was identified in this study, a finding that has not previously been documented. The use of proteomics tools allowed for the identification of peptides involved in drug resistance and the elucidation of Candida colonization mechanisms in HIV-infected African patients.

Philosophiae Doctor - PhD / One of the most common HIV-associated opportunistic infections is candidiasis, caused by Candida albicans or other Candida species. In immune suppressed subjects, this commensal organism can cause an increase in patient morbidity and mortality due to oropharyngeal or systemic dissemination. Limited information exists on the prevalence and antifungal susceptibility of Candida species in the African continent, the most HIV-affected region globally and home to new and emerging drug resistant Candida species. The mechanisms of Candida drug resistance in the African continent have also not been described. In this study, 255 Candida species isolated from the oral mucosa of HIV-positive South African and Cameroonian patients were identified using differential and chromogenic media and their drug susceptibility profiles tested using the disk diffusion method and the TREK Sensititre system, an automated broth microdilution method. Candida cell wall fractions were run on SDSPAGE and HPLC-MS with the aim of identifying peptides specifically expressed by antifungal drug resistant isolates. Comparisons between the two groups of isolates revealed differences in Candida species prevalence and drug susceptibility with interesting associations observed between specific drug resistance and duration of ARV therapy. This study showed that fluconazole, the drug of choice for the treatment of candidiasis in the African continent, is not an effective therapy for most cases of Candida infection, and suggests that regional surveillance be implemented in the continent. A multiple-drug resistant Candida strain was identified in this study, a finding that has not previously been documented. The use of proteomics tools allowed for the identification of peptides involved in drug resistance and the elucidation of Candida colonization mechanisms in HIV-infected African patients.

Although A. fumigatus strains are generally susceptible to azoles, recently, acquired resistance to a number of antifungal compounds has been reported, especially to triazoles possibly due to widespread clinical use of triazoles or through exposure to azole fungicides in the environment. The significant clinical problem of azole resistance has led to study the antifungal resistance mechanisms for developing effective therapeutic strategies. Of 230 clinical A. fumigatus isolates submitted during 2008 and 2009 to the Mycology Reference Centre Manchester, UK (MRCM), 64 (28%) were azole resistant and 14% and 20% of patients had resistant isolates, respectively. Among the resistant isolates, 62 of 64 (97%) were itraconazole resistant, 2 of 64 (3%) were only voriconazole resistant and 78% were multi-azole resistant. The gene encoding 14-α sterol demethylase (cyp51A) was analyzed in 63 itraconazole resistant (ITR-R) and 16 ITR-susceptible clinical and environmental isolates of A. fumigatus respectively. Amino acid substitutions in the cyp51A, the commonest known mechanism of azole resistance in A. fumigatus, were found in some ITR-R isolates. Fifteen different amino acid substitutions were found in the cyp51A three of which, A284T, M220R and M220W, have not been previously reported. In addition, several mutations were found in the cyp51A gene in one of the A. fumigatus environmental isolates. Importantly, a remarkably increased frequency of azole-resistant isolates without cyp51A mutations was observed in 43% of isolates and 54% of patients. Other mechanisms of resistance must be responsible for resistance. In order to assess the contribution of transporters and other genes to resistance, particular resistant isolates that did not carry a cyp51A mutation were studied. The relative expression of three novel transporter genes; ABC11, MFS56 and M85 as well as cyp51A, cyp51B, AfuMDR1, AfuMDR2 AfuMDR3, AfuMDR4 and atrF were assessed using real-time RT-PCR in both azole susceptible and resistant isolates, without cyp51A mutations. Interestingly, deletion of ABC11, MFS56 and M85 from a wild-type strain increased A. fumigatus susceptibility to azoles and these genes showed changes in expression levels in many ITR-R isolates. Most ITR-R isolates without cyp51A mutations showed either constitutive high-level expression of the three novel genes or induction of expression upon exposure to itraconazole. One isolate highly over-expressed cyp51B, a novel finding. Our results are most consistent with over-expression of one or more of these genes in ITR-R A. fumigatus without cyp51A mutations being at least partially responsible for ITR resistance. Multiple concurrent possible resistance mechanisms were found in some isolates. My work probably explains the mechanism(s) of resistance in A. fumigatus isolates with cyp51A mutations. Other ITR resistance mechanisms are also possible. To determine taxonomic relationships among A. fumigatus clinical and environmental isolates, the sequences of the ITS, β-tubulin, actin and calmodulin gene of 23 clinical and 16 environmental isolates were analyzed phylogenetically. Actin and calmodulin sequences proved to be good for species differentiation of A. fumigatus while both ITS, β-tubulin regions did not, in this dataset. Many cryptic species of A. fumigates (complex) were found. All environmental A. fumigates complex isolates were ITR susceptible and no cross resistance was found.

<p dir="ltr"><i>Candida glabrata</i> is a member of the gut microbiota that can become an opportunistic pathogen under certain conditions. It is known for its inherent resistance to azole antifungal drugs and its ability to rapidly develop resistance during treatment. However, the regulatory mechanisms that enable this commensal organism to survive in low-oxygen environments, such as the gut, and to develop antifungal resistance when it becomes pathogenic, are not fully understood. In this study, we demonstrate for the first time the roles of two zinc cluster transcription factors in <i>C. glabrata</i>, Hap1A and Hap1B, in contributing to azole drug resistance in both laboratory strains and drug-resistant clinical isolates, adaptation to hypoxia, and resistance to other antifungal drugs like polyenes and echinocandins under specific conditions.</p><p dir="ltr">Azole drugs, which target the Erg11 protein, are widely used to treat <i>Candida</i> infections. The regulation of azole-induced <i>ERG</i> gene expression and activation of drug efflux pumps in <i>C. glabrata</i> has primarily been linked to the zinc cluster transcription factors Upc2A and Pdr1. Here, we investigated the roles of <i>S. cerevisiae</i> Hap1 orthologs, Hap1A and Hap1B, in <i>C. glabrata</i> as direct regulators of <i>ERG</i> genes upon azole exposure.</p><p dir="ltr">Our research shows that deleting <i>HAP1</i> in the yeast model <i>S. cerevisiae</i> increases sensitivity to fluconazole due to the failure to induce <i>ERG11 </i>expression in the <i>hap1Δ</i> mutant compared to the wild-type strain. Although <i>C. glabrata</i> is closely related to <i>S. cerevisiae</i>, a whole genome duplication (WGD) event allowed <i>C. glabrata</i> to retain two HAP1 ohnologs, while <i>S. cerevisiae</i> lost one copy. Through phylogenetic and syntenic analyses, we identified Hap1A and Hap1B in <i>C. glabrata</i> as ohnologs of Hap1 in <i>S. cerevisiae</i>, which is known to regulate <i>ERG</i> gene expression under both aerobic and hypoxic conditions. Interestingly, deleting <i>HAP1B</i> in <i>C. glabrata</i> increased sensitivity to both triazole and imidazole drugs, similar to Hap1 in <i>S. cerevisiae</i>, while deleting <i>HAP1A </i>did not affect azole sensitivity.</p><p dir="ltr">Gene expression analysis revealed that the increased azole sensitivity in the <i>hap1BΔ </i>strain was due to reduced azole-induced <i>ERG</i> gene expression, leading to lower total endogenous ergosterol levels. Additionally, the loss of <i>HAP1B</i> in <i>C. glabrata</i> clinical isolates like SM1 and BG2, as well as in drug-resistant strains like SM3, also led to increased azole hypersusceptibility. While it was already known that losing <i>UPC2A</i> in <i>C. glabrata</i> increases azole sensitivity, our study is the first to demonstrate that the combined loss of both <i>HAP1B </i>and <i>UPC2A</i> makes <i>C. glabrata</i> strains even more sensitive to azoles than losing either gene alone. Additionally, we show that the loss of both <i>HAP1B </i>and the H3K4 histone methyltransferase <i>SET1</i> increases azole hypersensitivity more than the loss of either gene alone.</p><p dir="ltr">Interestingly, the Hap1A protein is barely detectable under aerobic conditions but is specifically induced under hypoxia, where it plays a crucial role in repressing <i>ERG</i> genes. In the absence of Hap1A, Hap1B compensates by acting as a transcriptional repressor. Our RNA sequencing analysis further showed that losing both <i>HAP1A</i> and <i>HAP1B</i> not only affects genes in the ergosterol biosynthesis pathway but also upregulates iron transport-related genes <i>FET3 </i>and <i>FTR1</i>. Moreover, we found that the hypoxic growth defect caused by the loss of both <i>HAP1A</i> and <i>HAP1B</i> is exacerbated when treated with the echinocandin caspofungin and the cell wall-damaging agent calcofluor white, indicating that these Hap1 ohnologs contribute to maintaining cell wall integrity under hypoxic conditions. Since <i>HAP1A</i> transcript levels remain stable under aerobic conditions, we suspect that Hap1A expression is regulated post-transcriptionally.</p><p dir="ltr">Furthermore, we discovered that the simultaneous loss of both HAP1A and HAP1B leads to increased hypersensitivity to the polyene antifungal drug amphotericin B, though the exact mechanism behind this phenotype remains unclear. Altogether, our study is the first to show that Hap1A and Hap1B have evolved distinct roles, enabling <i>C. glabrata</i> to adapt to specific host and environmental conditions.</p>

INTRODUÇÃO: A frequência de Candida parapsilosistem apresentado considerável aumento em UTIs neonatais. Embora a taxa de resistência dessa espécie aos azólicos seja baixa, recentemente têm sido relatados surtos de candidemia por isolados resistentes. A capacidade de adesão e formação de biofilme por essa espécie confere maior potencial patogênico e resistência aos antifúngicos. Portanto, a vigilância epidemiológica, tanto da resistência aos antifúngicos como da virulência dos isolados, é fundamental para o controle e prevenção das infecções e surtoshospitalares. A técnica de MALDI-TOF MS pode ser uma ferramenta útil para realizar análises proteômicas das células planctônicas e sésseis de Candida parapsilosis,e identificar possíveis alvos terapêuticos ou biomarcadores, específicos do biofilme. MÉTODOS: Isolados clínicos do complexo Candida parapsilosis de dois hospitais universitários públicos brasileiros, foram submetidos à identificação por RAPD, RFLP e MALDI-TOF MS e aos testes de suscetibilidade aos antifúngicos. Ensaios de formação de biofilme foram realizados para quantificar a biomassa, a atividade metabólica e ainda, avaliar atividade in vitrodos antifúngicos contra as células sésseis dos isolados com alta formação de biofilme. A análise proteômica por MALDI-TOF MS das células planctônicas e sésseis dos isolados com alta formação de biofilme, foi realizada nas plataformas VITEK-MS(TM) e Microflex(TM). Isolados de Candida parapsilosis (sensu stricto) foram genotipados por PFGE e análise de microssatélites. Os genótipos foram correlacionados com dadosclínicos, para investigar a ocorrência de um surto em CTI adulto, e as sequências do gene ERG11dos isolados não suscetíveis aos azólicos (NSA) foram analisadas. RESULTADOS: Foram obtidos 38 isolados do complexo Candida parapsilosis, sendo Candida parapsilosis(sensu stricto) a espécie de maior frequência, superando 80% em ambos os hospitais, seguida de C. orthopsilosis e C. metapsilosis. Embora todos os isolados tenham sido suscetíveis à anfotericina B ( < 2 mg/L) e apresentado suscetibilidade intermediária à anidulafungina, caspofungina e micafungina ( > 0,002 mg/L), elevada frequência de não suscetibilidade (resistência ou suscetibilidade intermediária) ao fluconazol e voriconazol foi observada entre isolados de um dos hospitais. Alta formação de biofilme foi observada apenas entre os isolados da espécie Candida parapsilosis(sensu stricto). Por outro lado, a maioria dos isolados NSA, apresentou baixa formação de biofilme e baixa atividade metabólica. Apenas anfotericina B apresentou atividade contra os biofilmes de Candida parapsilosis. As duas plataformas de MALDI-TOF MS conseguiram diferenciar os perfis proteômicos das células planctônicas e sésseis dos isolados. A genotipagem de Candida parapsilosis(sensu stricto) revelou a persistência de isolados clonais NSA e a mutação A395T no gene ERG11foi identificada exclusivamente entre os isolados resistentes ao azólicos. O uso de corticosteroide foi associado, estatisticamente, com a ocorrência de isolados clonais NSA. CONCLUSÕES: Candida parapsilosis (sensu stricto) se mantém como a principal espécie do complexo em infecções sanguíneas. Isolados resistentes aos azólicos, com mutações no gene ERG11, ocorreram nos dois hospitais avaliados. A correlação dos genótipos com os dados clínicos evidenciou a ocorrência de um surto envolvendo isolados clonais NSA, com associação estatisticamente significativa, ao uso prévio de corticosteroides. Candida parapsilosis (sensu stricto) foi a única espécie que apresentou alta formação de biofilme, o qual demonstrou elevada resistência às equinocandinas. As duas plataformas de MALDI-TOF MS, diferenciaram os perfis proteômicos, das células planctônicas e sésseis de Candida parapsilosis, demonstrando o potencial emprego dessa tecnologia na identificação de possíveis alvos terapêuticos ou biomarcadores, específicos de biofilmes / INTRODUCTION: The frequency of Candida parapsilosis isolates has increased considerably in neonatal ICUs. Although resistance to azoles is usually low in this species, candidemia outbreaks by resistant isolates have been recently reported. Theability of adhesion and biofilm formation by this species confers higher pathogenic potential and resistance to antifungal agents. Therefore, establishment of profiles of antifungal susceptibility and virulence, besides the epidemiological surveillance ofC. parapsilosisisolates are essential for the control and prevention of nosocomial infections and outbreaks. The MALDI-TOF MS technique can be a useful tool to perform proteomic analyzes of the planktonic and sessile cells of Candida parapsilosis, identifying possible biofilm-specific therapeutic targets or biomarkers. METHODS: Candida parapsilosisclinical isolates from two Brazilian public university hospitals were identified by RAPD, RFLP and MALDI-TOF MS and submitted to antifungal susceptibility tests. Biofilm formation assays were carried out to quantify the biomass and metabolic activity, and to evaluate the in vitroactivity of antifungal drugs against the sessile cells of the isolates with high biofilm formation. Proteomic analysis of the planktonic and sessile cells of the isolates with high biofilm formation was performed in two MALDI-TOF MS platforms, VITEK-MS(TM) and Microflex(TM). Candida parapsilosis(sensu stricto) isolates were genotyped by PFGE and microsatellite analysis. The genotypes were correlated with clinical data to investigate the occurrence of an outbreak in the adult ICU andERG11gene sequences from non-susceptible to azoles (NSA) isolates were also analyzed. RESULTS: 38 clinical isolates of the Candida parapsilosiscomplex were obtained, with Candida parapsilosis(sensu stricto) being the most frequent species (exceeding 80% in both hospitals), followed by C. orthopsilosisand C. metapsilosis. Although all isolates were susceptible to amphotericin B ( < 2 mg/L) and showed intermediate susceptibility to anidulafungin, caspofungin e micafungin ( > 0,002 mg/L), high frequency of non-susceptibility (resistance or intermediate susceptibility) to fluconazole and voriconazole was observed among isolates from one of the hospitals. High biofilm formation was only observed among isolates of the Candida parapsilosis. (sensu stricto) species. On the other hand, most of the NSA isolates presented low biofilm formation and low metabolic activity. Only amphotericin B showed activity against Candida parapsilosisbiofilms. The two MALDI-TOF MS platforms were able to differentiate the proteomic profiles of planktonic and sessile cells of isolates. Candida parapsilosis(sensu stricto) genotyping revealed the persistence of clonal NSA isolates. The A395T mutation in the ERG11gene was identified exclusively among azole resistant isolates. The use of corticosteroid was statistically associated with the occurrence of clonal NSA isolates. CONCLUSIONS: Candida parapsilosis(sensu stricto) remains the main species of the complex in bloodstream infections. Azole-resistant isolates with mutations in the ERG11gene are emerging in the two hospitals evaluated. Additionally, the correlation between the genotypes and the clinical data showed the occurrence of an outbreak involving isolates resistant to azoles, with a statistically significant association with previous use of corticosteroids. Candida parapsilosis(sensu stricto) was the only species that presented high biofilm formation and resistance against echinocandins. The two MALDI-TOF MS platforms differentiated the proteomic profiles of the planktonic and sessile cells of Candida parapsilosis, demonstrating the potential use of this technology to identify possible biofilm-specific therapeutic targets or biomarkers

INTRODUÇÃO: A frequência de Candida parapsilosistem apresentado considerável aumento em UTIs neonatais. Embora a taxa de resistência dessa espécie aos azólicos seja baixa, recentemente têm sido relatados surtos de candidemia por isolados resistentes. A capacidade de adesão e formação de biofilme por essa espécie confere maior potencial patogênico e resistência aos antifúngicos. Portanto, a vigilância epidemiológica, tanto da resistência aos antifúngicos como da virulência dos isolados, é fundamental para o controle e prevenção das infecções e surtoshospitalares. A técnica de MALDI-TOF MS pode ser uma ferramenta útil para realizar análises proteômicas das células planctônicas e sésseis de Candida parapsilosis,e identificar possíveis alvos terapêuticos ou biomarcadores, específicos do biofilme. MÉTODOS: Isolados clínicos do complexo Candida parapsilosis de dois hospitais universitários públicos brasileiros, foram submetidos à identificação por RAPD, RFLP e MALDI-TOF MS e aos testes de suscetibilidade aos antifúngicos. Ensaios de formação de biofilme foram realizados para quantificar a biomassa, a atividade metabólica e ainda, avaliar atividade in vitrodos antifúngicos contra as células sésseis dos isolados com alta formação de biofilme. A análise proteômica por MALDI-TOF MS das células planctônicas e sésseis dos isolados com alta formação de biofilme, foi realizada nas plataformas VITEK-MS(TM) e Microflex(TM). Isolados de Candida parapsilosis (sensu stricto) foram genotipados por PFGE e análise de microssatélites. Os genótipos foram correlacionados com dadosclínicos, para investigar a ocorrência de um surto em CTI adulto, e as sequências do gene ERG11dos isolados não suscetíveis aos azólicos (NSA) foram analisadas. RESULTADOS: Foram obtidos 38 isolados do complexo Candida parapsilosis, sendo Candida parapsilosis(sensu stricto) a espécie de maior frequência, superando 80% em ambos os hospitais, seguida de C. orthopsilosis e C. metapsilosis. Embora todos os isolados tenham sido suscetíveis à anfotericina B ( < 2 mg/L) e apresentado suscetibilidade intermediária à anidulafungina, caspofungina e micafungina ( > 0,002 mg/L), elevada frequência de não suscetibilidade (resistência ou suscetibilidade intermediária) ao fluconazol e voriconazol foi observada entre isolados de um dos hospitais. Alta formação de biofilme foi observada apenas entre os isolados da espécie Candida parapsilosis(sensu stricto). Por outro lado, a maioria dos isolados NSA, apresentou baixa formação de biofilme e baixa atividade metabólica. Apenas anfotericina B apresentou atividade contra os biofilmes de Candida parapsilosis. As duas plataformas de MALDI-TOF MS conseguiram diferenciar os perfis proteômicos das células planctônicas e sésseis dos isolados. A genotipagem de Candida parapsilosis(sensu stricto) revelou a persistência de isolados clonais NSA e a mutação A395T no gene ERG11foi identificada exclusivamente entre os isolados resistentes ao azólicos. O uso de corticosteroide foi associado, estatisticamente, com a ocorrência de isolados clonais NSA. CONCLUSÕES: Candida parapsilosis (sensu stricto) se mantém como a principal espécie do complexo em infecções sanguíneas. Isolados resistentes aos azólicos, com mutações no gene ERG11, ocorreram nos dois hospitais avaliados. A correlação dos genótipos com os dados clínicos evidenciou a ocorrência de um surto envolvendo isolados clonais NSA, com associação estatisticamente significativa, ao uso prévio de corticosteroides. Candida parapsilosis (sensu stricto) foi a única espécie que apresentou alta formação de biofilme, o qual demonstrou elevada resistência às equinocandinas. As duas plataformas de MALDI-TOF MS, diferenciaram os perfis proteômicos, das células planctônicas e sésseis de Candida parapsilosis, demonstrando o potencial emprego dessa tecnologia na identificação de possíveis alvos terapêuticos ou biomarcadores, específicos de biofilmes / INTRODUCTION: The frequency of Candida parapsilosis isolates has increased considerably in neonatal ICUs. Although resistance to azoles is usually low in this species, candidemia outbreaks by resistant isolates have been recently reported. Theability of adhesion and biofilm formation by this species confers higher pathogenic potential and resistance to antifungal agents. Therefore, establishment of profiles of antifungal susceptibility and virulence, besides the epidemiological surveillance ofC. parapsilosisisolates are essential for the control and prevention of nosocomial infections and outbreaks. The MALDI-TOF MS technique can be a useful tool to perform proteomic analyzes of the planktonic and sessile cells of Candida parapsilosis, identifying possible biofilm-specific therapeutic targets or biomarkers. METHODS: Candida parapsilosisclinical isolates from two Brazilian public university hospitals were identified by RAPD, RFLP and MALDI-TOF MS and submitted to antifungal susceptibility tests. Biofilm formation assays were carried out to quantify the biomass and metabolic activity, and to evaluate the in vitroactivity of antifungal drugs against the sessile cells of the isolates with high biofilm formation. Proteomic analysis of the planktonic and sessile cells of the isolates with high biofilm formation was performed in two MALDI-TOF MS platforms, VITEK-MS(TM) and Microflex(TM). Candida parapsilosis(sensu stricto) isolates were genotyped by PFGE and microsatellite analysis. The genotypes were correlated with clinical data to investigate the occurrence of an outbreak in the adult ICU andERG11gene sequences from non-susceptible to azoles (NSA) isolates were also analyzed. RESULTS: 38 clinical isolates of the Candida parapsilosiscomplex were obtained, with Candida parapsilosis(sensu stricto) being the most frequent species (exceeding 80% in both hospitals), followed by C. orthopsilosisand C. metapsilosis. Although all isolates were susceptible to amphotericin B ( < 2 mg/L) and showed intermediate susceptibility to anidulafungin, caspofungin e micafungin ( > 0,002 mg/L), high frequency of non-susceptibility (resistance or intermediate susceptibility) to fluconazole and voriconazole was observed among isolates from one of the hospitals. High biofilm formation was only observed among isolates of the Candida parapsilosis. (sensu stricto) species. On the other hand, most of the NSA isolates presented low biofilm formation and low metabolic activity. Only amphotericin B showed activity against Candida parapsilosisbiofilms. The two MALDI-TOF MS platforms were able to differentiate the proteomic profiles of planktonic and sessile cells of isolates. Candida parapsilosis(sensu stricto) genotyping revealed the persistence of clonal NSA isolates. The A395T mutation in the ERG11gene was identified exclusively among azole resistant isolates. The use of corticosteroid was statistically associated with the occurrence of clonal NSA isolates. CONCLUSIONS: Candida parapsilosis(sensu stricto) remains the main species of the complex in bloodstream infections. Azole-resistant isolates with mutations in the ERG11gene are emerging in the two hospitals evaluated. Additionally, the correlation between the genotypes and the clinical data showed the occurrence of an outbreak involving isolates resistant to azoles, with a statistically significant association with previous use of corticosteroids. Candida parapsilosis(sensu stricto) was the only species that presented high biofilm formation and resistance against echinocandins. The two MALDI-TOF MS platforms differentiated the proteomic profiles of the planktonic and sessile cells of Candida parapsilosis, demonstrating the potential use of this technology to identify possible biofilm-specific therapeutic targets or biomarkers