KATIA CRISTINA DANTAS
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Patologia, 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
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- Importance of the association of molecular and immunological diagnosis in immunocompetent patient with Histoplasma capsulatum and Cryptoccocus neoformans infection: a case report(2014) DANTAS, Katia Cristina; FREITAS, Roseli Santos de; GARCIA, Roberta Scholz Pinto; SILVA, Marcos Vinicius da; MURICY, Edna Cleide Mendes; KOHARA, Valdelene Sayuri; VICENTINI, Adriana PardiniThis case reports an immunocompetent 29-year-old woman with suspected pneumonia, suggestive of fungal infection. Immunoblotting analysis reactivity against Histoplasma capsulatum and Paracoccidioides brasiliensis were observed. Nested-PCR in blood employing species-specific primers was positive for H. capsulatum and Cryptococcus neoformans. The evaluation of paucisymptomatic patients with positive results for H. capsulatum and C. neoformans could be relevant for the prevention as well as the possible evaluation of the reactivated quiescent foci. In conclusion, the associated methodology may have contributed to the monitoring endogenous reactivation of these diseases.
- The use of nested Polymerase Chain Reaction (nested PCR) for the early diagnosis of Histoplasma capsulatum infection in serum and whole blood of HIV-positive patients(2013) DANTAS, Katia Cristina; FREITAS, Roseli S.; MOREIRA, Adriana Pardini Vicentini; SILVA, Marcos Vinicius da; BENARD, Gil; VASCONCELLOS, Cidia; CRIADO, Paulo RicardoThe aim of the study was to detect the rDNA sequences and their regions in Histoplasma capsulatum, which could be considered species-specific and used as a molecular method for this diagnosis by the technique of nested polymerase chain reaction (nested PCR), employing specific sequences (primers) for H. capsulatum: 18S rDNA region (HC18), 100 kDa (HC100) and the sequence 5.8 S-ITS rDNA (HC5.8). The PCR sequences HC18, HC100 and HC5.8 resulted in a specificity of 100%. The molecular assays may increase the specificity, sensitivity and speed in the diagnosis of Histoplasmosis.
- Comparison of diagnostic methods to detect Histoplasma capsulatum in serum and blood samples from AIDS patients(2018) DANTAS, Katia Cristina; FREITAS, Roseli Santos de; SILVA, Marcos Vinicius da; CRIADO, Paulo Ricardo; LUIZ, Olinda do Carmo; VICENTINI, Adriana PardiniBackground Although early and rapid detection of histoplasmosis is essential to prevent morbidity and mortality, few diagnostic tools are available in resource-limited areas, especially where it is endemic and HIV/AIDS is also epidemic. Thus, we compared conventional and molecular methods to detect Histoplasma capsulatum in sera and blood from HIV/AIDS patients. Methodology We collected a total of 40 samples from control volunteers and patients suspected of histoplasmosis, some of whom were also infected with other pathogens. Samples were then analyzed by mycological, serological, and molecular methods, and stratified as histoplasmostic with (group I) or without AIDS (group II), uninfected (group III), and infected with HIV and other pathogens only (group IV). All patients were receiving treatment for histoplasmosis and other infections at the time of sample collection. Results Comparison of conventional methods with nested PCR using primers against H. capsulatum 18S rRNA (HC18S), 5.8S rRNA ITS (HC5.8S-ITS), and a 100 kDa protein (HC100) revealed that sensitivity against sera was highest for PCR with HC5.8S-ITS, followed by immunoblotting, double immunodiffusion, PCR with HC18S, and PCR with HC100. Specificity was equally high for double immunodiffusion, immunoblotting and PCR with HC100, followed for PCR with HC18S and HC5.8-ITS. Against blood, sensitivity was highest for PCR with HC5.8S-ITS, followed by PCR with HC18S, Giemsa staining, and PCR with HC100.Specificity was highest for Giemsa staining and PCR with HC100, followed by PCR with HC18S and HC5.8S-ITS. PCR was less efficient in patients with immunodeficiency due to HIV/AIDS and/or related diseases. Conclusion Molecular techniques may detect histoplasmosis even in cases with negative serology and mycology, potentially enabling early diagnosis.
- 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.