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
2 resultados
Resultados de Busca
Agora exibindo 1 - 2 de 2
- Rapid identification of moulds and arthroconidial yeasts from positive blood cultures by MALDI-TOF mass spectrometry(2016) ALMEIDA JR., Joao N. de; SZTAJNBOK, Jaques; SILVA JUNIOR, Afonso Rafael da; VIEIRA, Vinicius Adriano; GALASTRI, Anne Layze; BISSOLI, Leandro; LITVINOV, Nadia; NEGRO, Gilda Maria Barbaro Del; MOTTA, Adriana Lopes; ROSSI, Flavia; BENARD, GilMoulds and arthroconidial yeasts are potential life-threatening agents of fungemia in immunocompromised patients. Fast and accurate identification (ID) of these pathogens hastens initiation of targeted antifungal therapy, thereby improving the patients' prognosis. We describe a new strategy that enabled the identification of moulds and arthroconidial yeasts directly from positive blood cultures by MALDI-TOFmass spectrometry (MS). Positive blood cultures (BCs) with Gram staining showing hyphae and/or arthroconidia were prospectively selected and submitted to an in-house protein extraction protocol. Mass spectra were obtained by Vitek MS (TM) system, and identifications were carried out with in the research use only (RUO) mode with an extended database (SARAMIS (TM) [v.4.12] plus in-house database). Fusarium solani, Fusarium verticillioides, Exophiala dermatitidis, Saprochaete clavata, and Trichosporon asahii had correct species ID by MALDI-TOF MS analysis of positive BCs. All cases were related to critically ill patients with high mortality fungemia and direct ID from positive BCs was helpful for rapid administration of targeted antifungal therapy.
- 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. deCandida 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.