VIVIANE MAZO FAVERO GIMENES
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/53 - Laboratório de Micologia, Hospital das Clínicas, Faculdade de Medicina
LIM/53 - Laboratório de Micologia, Hospital das Clínicas, Faculdade de Medicina
5 resultados
Resultados de Busca
Agora exibindo 1 - 5 de 5
- Aspects related to biofilm production and antifungal susceptibility of clinically relevant yeasts of the genus Trichosporon(2023) LARA, Bruna Rossini; CAMARGO, Bruno Braidotti de; PAULA, Claudete Rodrigues; MONARI, Gabrielle Pires de Morais; GARCES, Hans Garcia; ARNONI, Mariana Volpe; SILVEIRA, Monica; GIMENES, Viviane Mazo Favero; LEITE JUNIOR, Diniz Pereira; BONFIETTI, Lucas Xavier; OLIVEIRA, Lidiane; MELHEM, Marcia de Souza Carvalho; AULER, Marcos; RAMOS, Regina Teixeira Barbieri; DIAS, Amanda Latercia Tranches; SILVA, Naiara Chaves; MOREIRA, Debora; RICHINI-PEREIRA, Virginia Bodelao; ANVERSA, Lais; RUIZ, Luciana da SilvaLay Summary This study investigated 59 isolates of the medically important yeast Trichosporon in relation to their ability to form biofilms and the susceptibility of biofilms to antifungal agents. All isolates were able to produce biofilms and biofilms showed lower antifungal susceptibility. Trichosporonosis corresponds to a systemic fungal disease that leads to high mortality rates and is frequently associated with medical devices. It affects immunosuppressed patients in particular and is strongly linked to acquired human immunodeficiency, organ and tissue transplants, and malignant hematologic diseases such as leukemia and lymphomas. Trichosporon infections have been increasingly reported worldwide; however, little information is available either about their characteristics or the causative microorganism. Thus, the aims of the present study were: to investigate 59 yeasts of the genus Trichosporon by verifying the biofilm formation capacity of isolates; to analyze the susceptibility patterns of planktonic cells against the antifungals fluconazole, itraconazole, amphotericin-B, voriconazole, and caspofungin by comparing European Committee for Antimicrobial Susceptibility Testing (EUCAST) broth microdilution technique with the commercial method Etest; and to assess the susceptibility patterns of biofilm cells (sessile) against the same antifungals through broth microdilution. The ability to form biofilm on the surface of polystyrene plates was noted for all isolates, and 54.3% of samples were considered strong producers. Comparison between the antifungal susceptibility techniques evidenced that Etest showed higher and discordant minimum inhibitory concentrations (MICs) from those obtained by the microdilution method, especially for fluconazole, itraconazole, and caspofungin. Considering the susceptibility of biofilms, most species had high MIC50 and MIC90 against the tested antifungals, showing 4-to-66-fold higher concentrations for amphotericin B and 2-to-33-fold greater concentrations for caspofungin. These results highlight the importance of further studies with Trichosporon spp. for comparison between laboratory findings and in vivo response, considering both the susceptibility tests and the behavior of biofilm cells against drugs.
- Comparing the phenotypic, genotypic, and proteomic identification of Trichosporon species: A globally emerging yeast of medical importance(2021) LARA, Bruna Rossini; CAMARGO, Bruno Braidotti de; PAULA, Claudete Rodrigues; LEITE JUNIOR, Diniz Pereira; GARCES, Hans Garcia; ARNONI, Mariana Volpe; SILVEIRA, Monica; GIMENES, Viviane Mazo Favero; SIQUEIRA, Lumena Pereira Machado; TAKAHASHI, Juliana Possatto Fernandes; MELHEM, Marcia de Souza Carvalho; RICHINI-PEREIRA, Virginia Bodelao; ANVERSA, Lais; RUIZ, Luciana da SilvaTrichosporon spp. are widely distributed in the nature, comprising species that inhabit different ecological niches and can be found in the water, soil, and body surface of animals and humans. Such microorganisms have been classically associated with superficial infections; however, in the last decades, they have also been related to disseminated infections in immunocompromised patients, behaving as opportunistic agents, which demands rapid and accurate species identification for efficient therapy. Concordance level between the traditional phenotypic method and the molecular technique (gold standard) in the identification of all 59 Trichosporon samples was 59.3%. Identification concordance between MALDI-TOF spectrometry and the molecular technique was 71.2%. No isolate of environmental origin was identifiable by MALDI-TOF mass spectrometry (MS), and 100% of such environmental isolates were discordant for IGS region sequencing and phenotypic characterization. Both comparisons evidenced greatest concordance in the identification of T. asahii. The species T. debeurmannianum, T. dermatis, T. venhuisii and T. insectorum were not properly identified by both MALDI-TOF MS and the phenotypic technique. MALDI-TOF MS, in particular, seems to be appropriate to investigate yeasts of the genus Trichosporon; however, database updates are still necessary, especially for species that are not common in the clinical routine. With the aim of helping understand the aspects involved in early and accurate diagnosis of infections caused by this opportunistic agent, the present study compared the phenotypic, molecular (IGS region) and mass-spectrometry (MALDI-TOF) identification of 59 yeasts of the genus Trichosporon which had clinical and environmental origin and were kept in a mycology collection.
- Whole-genome sequencing of Candida haemulonii species complex from Brazil and the United States: Genetic diversity and antifungal susceptibility(2023) RODRIGUES, Dality Keffelen de Barros; LOCKHART, Shawn R.; BERKOW, Elizabeth L.; GADE, Lalitha; BONFIETTI, Lucas Xavier; GIMENES, Viviane Mazo Favero; RUIZ, Luciana Silva; MACIONI, Milena Bronze; MELHEM, Marcia de Souza CarvalhoLay Summary Candida haemulonii complex species is worldwide distributed, and this study aimed to evaluate the resistance to antifungal drugs in cases from Brazil and the United States, and also compare their genetic relationships. A total of 50 strains were studied; most of them from Brazil were from cases of bloodstream infections, while the strains from the United States came from cases of wounds and may be associated with diabetic patients. The vast majority of strains were resistant to amphotericin B, one of the most effective drugs, and susceptible to fluconazole. In addition, 50% of C. pseudohaemulonii strains were resistant to echinocandins. The strains from Brazil and the United States had no genetic relationship and formed two distinct groups. In three Brazilian hospitals, strains were clonal, indicating an intra-hospital transmission. Our findings contribute to guiding therapy in bloodstream fungal infections caused by C. haemulonii species and alerting for nosocomial transmission of this yeast complex species. Candida haemulonii complex species can be multidrug-resistant and cause infections such as candidemia. This study determined the genetic relationship between isolates from Brazil and the United States through whole-genome sequencing and performed antifungal susceptibility testing to investigate drug resistance. Contrary to what is widely described, most isolates were susceptible to azoles. However, an atypical susceptibility profile was found in 50% of Candida pseudohaemulonii strains, including resistance to the three echinocandins. Isolates from both countries formed distinct clusters with wide genetic diversity. Isolates from three hospitals in Brazil were clonal and involved in candidemia cases, pointing to the importance of improving hospital infection control measures and molecular identification.
- Evaluating VITEK MS for the identification of clinically relevant Aspergillus species(2020) AMERICO, Fernanda M.; SIQUEIRA, Lumena P. Machado; NEGRO, Gilda Maria B. Del; GIMENES, Viviane M. Favero; TRINDADE, Mario Roberto S.; MOTTA, Adriana L.; FREITAS, Roseli Santos de; ROSSI, Flavia; COLOMBO, Arnaldo L.; BENARD, Gil; ALMEIDA JUNIOR, Joao N. deAspergillus spp. identification has become more relevant in clinical practice since azole-resistant cryptic species have been related to invasive fungal infections. Conventional morphologic identification is not able to discriminate Aspergillus species, and DNA sequencing is not feasible for clinical laboratories. MALDI-TOF mass spectrometry is an emergent technology that has been explored to provide fast and accurate identification of microorganisms, including clinically relevant moulds. However, only a few studies have explored the platform VITEK MS for the identification of Aspergillus species. Hence, we provided additional data regarding the performance of the VITEK MS system for the identification of Aspergillus species, including azole-resistant ones. We also improved the RUO system by adding additional spectral profiles from well-identified Aspergillus strains belonging to different noncryptic and cryptic species. The IVD library correctly identified 91.6% of the organisms at genus and section level, and 84.7% at species level, including the azole-resistant Aspergillus lentulus and Aspergillus calidoustus. The organisms belonging to Aspergillus cryptic species had only 31.2% of correct species identification. The RUO library plus our in-house SuperSpectra correctly identified 100% of the organisms at genus and section level and 91.6% at species level. Among organisms belonging to Aspergillus cryptic species, 68.7% had correct species identification. Some closely related Aspergillus cryptic species showed similar spectral profiles and were difficult to be differentiated.
- Environmental Clonal Spread of Azole-Resistant Candida parapsilosis with Erg11-Y132F Mutation Causing a Large Candidemia Outbreak in a Brazilian Cancer Referral Center(2021) THOMAZ, Danilo Y.; ALMEIDA, Joao N. de; SEJAS, Odeli N. E.; NEGRO, Gilda M. B. Del; CARVALHO, Gabrielle O. M. H.; GIMENES, Viviane M. F.; SOUZA, Maria Emilia B. de; ARASTEHFAR, Amir; CAMARGO, Carlos H.; MOTTA, Adriana L.; ROSSI, Flavia; PERLIN, David S.; FREIRE, Maristela P.; ABDALA, Edson; BENARD, GilClonal outbreaks due to azole-resistant Candida parapsilosis (ARCP) isolates have been reported in numerous studies, but the environmental niche of such isolates has yet to be defined. Herein, we aimed to identify the environmental niche of ARCP isolates causing unremitting clonal outbreaks in an adult ICU from a Brazilian cancer referral center. C. parapsilosis sensu stricto isolates recovered from blood cultures, pericatheter skins, healthcare workers (HCW), and nosocomial surfaces were genotyped by multilocus microsatellite typing (MLMT). Antifungal susceptibility testing was performed by the EUCAST (European Committee for Antimicrobial Susceptibility Testing) broth microdilution reference method and ERG11 was sequenced to determine the azole resistance mechanism. Approximately 68% of isolates were fluconazole-resistant (76/112), including pericatheter skins (3/3, 100%), blood cultures (63/70, 90%), nosocomial surfaces (6/11, 54.5%), and HCW's hands (4/28, 14.2%). MLMT revealed five clusters: the major cluster contained 88.2% of ARCP isolates (67/76) collected from blood (57/70), bed (2/2), pericatheter skin (2/3), from carts (3/7), and HCW's hands (3/27). ARCP isolates were associated with a higher 30 day crude mortality rate (63.8%) than non-ARCP ones (20%, p = 0.008), and resisted two environmental decontamination attempts using quaternary ammonium. This study for the first time identified ARCP isolates harboring the Erg11-Y132F mutation from nosocomial surfaces and HCW's hands, which were genetically identical to ARCP blood isolates. Therefore, it is likely that persisting clonal outbreak due to ARCP isolates was fueled by environmental sources. The resistance of Y132F ARCP isolates to disinfectants, and their potential association with a high mortality rate, warrant vigilant source control using effective environmental decontamination.