ROSELI SANTOS DE FREITAS
Projetos de Pesquisa
Unidades Organizacionais
LIM/53 - Laboratório de Micologia, Hospital das Clínicas, Faculdade de Medicina
LIM/05 - Laboratório de Poluição Atmosférica Experimental, Hospital das Clínicas, Faculdade de Medicina
LIM/05 - Laboratório de Poluição Atmosférica Experimental, Hospital das Clínicas, Faculdade de Medicina
4 resultados
Resultados de Busca
Agora exibindo 1 - 4 de 4
- Fast and cost-effective protocol to produce Paracoccidioides spp. antigens(2023) FERNANDES-BERALDO, Karolina Rosa; FREITAS-XAVIER, Roseli Santos de; PARDINI-VICENTINI, AdrianaIntroduction. The existing methods for Paracoccidioides spp. antigen production are problematic in terms of standardization, specificity, stability, repeatability, and reproducibility.Objective. To optimize the methodology for Paracoccidioides spp. antigen production and evaluate its applicability in paracoccidioidomycosis immunodiagnosis.Materials and methods. The antigens were obtained from Paracoccidioides lutzii isolates (01, 66, and 8334), Paracoccidioides brasiliensis sensu stricto (113), and Paracoccidioides restripiensis (B-339). These fungi were grown at 36 degrees C +/- 1 degrees C, on modified Fava-Netto agar, according to Freitas et al. (2018). Paracoccidioides lutzii antigens were obtained after 5, 10, and 20 days of culture, whereas P. brasiliensis and P. restripiensis antigens were obtained after 10 days. Antigens were evaluated in natura, 10 and 20 times concentrated. Antigenic capacity was evaluated using a double immunodiffusion assay against serum samples from patients with paracoccidioidomycosis, histoplasmosis, and aspergillosis, and random blood donors.Results. Cross-reactivity between Paracoccidioides spp. antigens was observed when P. brasiliensis, P. restrepiensis antigens, and P. lutzii antigens were evaluated with the polyclonal antibodies against P. lutzii and P. brasiliensis, respectively. No cross-reactivity was obtained for polyclonal antibodies against Histoplasma capsulatum, Aspergillus fumigatus, and random blood donors. The proposed protocol allowed stable, repeatable, and reproducible genus-specific antigen production at a low cost and in a short cultivation time.Conclusion. The proposed protocol allowed us to obtain genus-specific antigens that can be developed and reproduced in all laboratories in Brazil and South America, where paracoccidioidomycosis is a neglected disease, contributing to an early diagnosis, especially in endemic regions, regardless of the species.
article Fast and cost-effective protocol for the production of Paracoccidioides spp. antigens(2023) FERNANDES-BERALDO, Karolina Rosa; FREITAS-XAVIER, Roseli Santos de; VICENTINI, Adriana PardiniIntroduction: Existing methods for the production of Paracoccidioides spp. antigens are problematic considering standardization, specificity, stability, repeatability, and reproducibility. Objective: To optimize the methodology for producing Paracoccidioides spp. antigens and to evaluate its applicability in paracoccidioidomycosis immunodiagnosis. Materials and methods: The antigens were obtained from isolates of Paracoccidioides lutzii (01, 66 and 8334), Paracoccidioides brasiliensis sensu stricto (113) and Paracoccidioides restripiensis (B-339) grown at 36 degrees +/- 1 degrees C, on modified Fava-Netto agar, according Freitas et al. (2018). The P. lutzii antigens were obtained after 5, 10 and 20 days of culture and those of P. brasiliensis and P. restripiensis, after 10 days. The antigens were evaluated in natura, 10 and 20 times concentrated. The antigenic capacity was evaluated using the double immunodiffusion assay against serum samples from patients with paracoccidioidomycosis, histoplasmosis, aspergillosis and from random blood donors. Results: Cross-reactivity between Paracoccidioides spp. antigens was observed when P. brasiliensis and P. restrepiensis antigens were evaluated against polyclonal antibody anti-P. lutzii and when P. lutzii antigens were evaluated against polyclonal antibody anti-P. brasiliensis. There was no cross-reactivity against polyclonal antibodies anti-Histoplasma capsulatum and anti-Aspergillus fumigatus and random blood donors. The proposed protocol allowed the production of gender-specific, stable, repeatable and reproducible antigens, in a shorter cultivation time and at a lower cost. Conclusion: The proposed protocol allowed obtaining gender-specific antigens and can be developed and reproduced in all laboratories in Brazil and South America, where paracoccidioidomycosis is neglected, contributing to the early diagnosis, especially in endemic regions, regardless of the species.- Seasonality of sporotrichosis in Brazil: A modelled analysis of the epidemic in Sao Paulo, 2011-2020(2023) FREITAS, Vera Lucia Teixeira de; ROCHA, Francisco Marcelo Monteiro; RIBEIRO, Emanoella Nogueira; LINDOSO, Jose Angelo Laulleta; BITTENCOURT, Amanda Azevedo; PIVETTA, Dhara Nicole Araujo Greco; BENARD, Gil; FREITAS-XAVIER, Roseli Santos deBackground: Sporotrichosis is an endemic subcutaneous mycosis classically caused by the Sporothrix schenckii species complex. Recently, sporotrichosis has emerged in Brazil as a cat-transmitted epidemic caused by a new species, Sporothrix brasiliensis. Objectives: To survey the clinical-epidemiological profile of all sporotrichosis cases diagnosed between 2011 and 2020 at a reference hospital in Sao Paulo metropolitan area and evaluate the annual distribution of cases in relation to seasonality. Methods: Patients' demographic and clinical-epidemiological data were surveyed. A generalized linear model was fitted to relate the quarterly number of sporotrichosis cases detected between 2015 and 2019 with precipitation and temperature series. Prediction of the number of cases from 2011 to 2014 was attempted based on the fitted model without the trend component that appears from 2015. Results: Among 271 suspected cases admitted during 2011-2020, 254 were confirmed by fungal isolation and/or clinical-epidemiological criteria. We observed that 2015 onwards the number of cases regularly increased during Autumn and Winter, the driest and coldest stations of the year. We verified that temperature series affected the number of cases (p = .005) because an increase of 1 degrees C in the temperature series was associated with a 14.24% decrease in the average cases number, with the average number of cases increasing by 10.96% (p < .0001) every quarter, corresponding to an annual increase of 52%. Between 2011 and 2014, the predicted number of sporotrichosis cases averaged 10-12 per year, with 33%-38% occurring in the winter. Conclusion: We hypothesize that sporotrichosis seasonality is associated with the felines' oestrus cycle, which may provide alternative, cat-directed approaches to the sporotrichosis epidemic control.
- Comparative analysis of diagnostic methods for the detection of Cryptococcus neoformans meningitis(2023) DANTAS, Katia Cristina; FREITAS-XAVIER, Roseli Santos de; LOMBARDI, Suzete Cleusa Ferreira Spina; MENDRONI JUNIOR, Alfredo; SILVA, Marcos Vinicius da; CRIADO, Paulo Ricardo; FREITAS, Vera Lucia Teixeira de; ALMEIDA, Terezinha Morato Bastos deAuthor summaryCryptococcal meningitis is an infectious disease of global importance with high morbidity and mortality, especially among individuals with HIV/AIDS. While there have been improvements in the last two decades in the diagnosis of Cryptococcus neoformans, the methods presently employed are problematic for public hospitals in Brazil and other locations due to their extreme cost. In this study, we present a low-cost option for detection and identification of C. neoformans in noninvasive serum sample in immunosuppressed individuals, including those with HIV/AIDS. A nested PCR (5.8SrDNA-ITS) associated with the latex agglutination test has high precision in detection of suspected Cryptococcus spp. BackgroundCryptococcosis is a devastating opportunistic infection in immunocompromised individuals, primarily in people living with HIV/AIDS. This study evaluated a protocol for the early diagnosis of meningitis due to C. neoformans, utilizing established molecular techniques from serum and CSF samples. MethodsThe 18S and 5.8S (rDNA-ITS) sequence-specific nested PCR assays were compared with direct India ink staining and the latex agglutination test for detection of C. neoformans in serum and cerebrospinal fluid (CSF) from 49 Brazilian suspected meningitis patients. Results were validated with samples obtained from 10 patients negative for cryptococcosis and HIV, and by analysis of standard C. neoformans strains. Principal findingsThe 5.8S DNA-ITS PCR was more sensitive (89-100%) and specific (100%) than the 18S rDNA PCR and conventional tests (India ink staining and latex agglutination) for identification of C. neoformans. While the 18S PCR exhibited a sensitivity (72%) similar to that of the latex agglutination assay in serum samples, it was superior to the latex agglutination assay when testing CSF, with a sensitivity of 84%. However, the latex agglutination was superior to the 18SrDNA PCR in specificity in CSF (92%). The 5.8S DNA-ITS PCR yielded the highest levels of accuracy (96-100%) of any test for detection (serological and mycological) of C. neoformans in both serum and CSF. ConclusionUse of the nested 5.8S PCR was superior to other techniques for the diagnosis of cryptococcosis. The possibility of using serum, a non-invasively collected material, in a targeted 5.8S PCR analysis to identify Cryptococcus spp. is recommended, especially in immunosuppressed patients. Our results indicate that nested 5.8S PCR can increase the diagnostic capability of cryptococcosis, and we suggest its use to monitor patients in the future.