AFONSO RAFAEL DA SILVA JUNIOR

Índice h a partir de 2011
3
Projetos de Pesquisa
Unidades Organizacionais
P ICHC, Hospital das Clínicas, Faculdade de Medicina

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Agora exibindo 1 - 2 de 2
  • article 35 Citação(ões) na Scopus
    Identification of Candida haemulonii Complex Species: Use of ClinProTools (TM) to Overcome Limitations of the Bruker Biotyper (TM), VITEK MS (TM) IVD, and VITEK MS (TM) RUO Databases
    (2016) GRENFELL, Rafaella C.; SILVA JUNIOR, Afonso R. da; NEGRO, Gilda M. B. Del; MUNHOZ, Regina B.; GIMENES, Viviane M. F.; ASSIS, Diego M.; ROCKSTROH, Anna C.; MOTTA, Adriana L.; ROSSI, Flavia; JULIANO, Luiz; BENARD, Gil; ALMEIDA JUNIOR, Joao N. de
    Candida haemulonli is now considered a complex of two species and one variety: C. haemulonii sensu strict, Candida duobushaemulonii and the variety C. haemulonii var. vulnera. Identification (ID) of these species is relevant for epidemiological purposes and for therapeutic management, but the different phenotypic commercial systems are unable to provide correct species ID for these emergent pathogens. Hence, we evaluated the MALDI-TOF MS performance for the ID of C. haemulonli species, analyzing isolates/strains of C. haemulonli complex species, Candida pseudohaemulonii and Candida auris by two commercial platforms, their databases and softwares. To differentiate C. haemulonli sensu sctricto from the variety vulnera, we used the ClinProTools (TM) models and a single-peak analysis with the software FlexAnalysis (TM). The Biotyper (TM) database gave 100% correct species ID for C. haemulonii sensu strict, C. pseudohaemulonii and C. auris, with 69% of correct species ID for C. duobushaemulonii. Vitek MS (TM) IVD database gave 100% correct species ID for C. haemulonii sensu stricto, misidentifying all C. duobushaemulonii and C. pseudohaemulonii as C. haemulonii, being unable to identify C. auris. The Vitek MS (TM) RUO database needed to be upgraded with in-house SuperSpectra to discriminate C. haemulonii sensu stricto, C. duobushaemulonii, C. pseudohaemulonii, and C. auris strains/isolates. The generic algorithm model from ClinProTools (TM) software showed recognition capability of 100% and cross validation of 98.02% for the discrimination of C. haemulonli sensu stricto from the variety vulnera. Single-peak analysis showed that the peaks 5670, 6878, or 13750 m/z can distinguish C. haemulonli sensu stricto from the variety vulnera.
  • article 12 Citação(ões) na Scopus
    Evaluation of Vitek MS for Differentiation of Cryptococcus neoformans and Cryptococcus gattii Genotypes
    (2019) SIQUEIRA, Lumena P. Machado; GIMENES, Viviane M. Favero; FREITAS, Roseli Santos de; MELHEM, Marcia de Souza Carvalho; BONFIETTI, Lucas Xavier; JR, Afonso Rafael da Silva; SANTOS, Leticia B. Souza; MOTTA, Adriana L.; ROSSI, Flavia; BENARD, Gil; JR, Joao N. de Almeida
    Cryptococcus neoformans and Cryptococcus gattii are the main pathogenic species of invasive cryptococcosis among the Cryptococcus species. Taxonomic studies have shown that these two taxa have different genotypes or molecular types with biological and ecoepidemiological peculiarities. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been proposed as an alternative method for labor-intensive methods for C. neoformans and C. gattii genotype differentiation. However, Vitek MS, one of the commercial MALDI-TOF MS instruments, has not been yet been evaluated for this purpose. Thus, we constructed an in-house database with reference strains belonging to the different C. neoformans (VNI, VNII, VNIII, and VNIV) and C. gattii (VGI, VGII, VGIII, and VGIV) major molecular types by using the software Saramis Premium (bioMerieux, Marcy-l'Etoile, France). Then, this new database was evaluated for discrimination of the different genotypes. Our in-house database provided correct identification for all C. neoformans and C. gattii genotypes; however, due to the intergenotypic mass spectral similarities, a careful postanalytic evaluation is necessary to provide correct genotype identification.