Comparison of DNA Extraction Protocols and Molecular Targets to Diagnose Tuberculous Meningitis.

Tuberculous meningitis (TBM) is a severe form of extrapulmonary tuberculosis. The aims of this study were to evaluate in-house molecular diagnostic protocols of DNA extraction directly from CSF samples and the targets amplified by qPCR as an accurate and fast diagnosis of TBM. One hundred CSF samples from 68 patients suspected of TBM were studied. Four DNA extraction techniques (phenol-chloroform-thiocyanate guanidine, silica thiocyanate guanidine, resin, and resin with ethanol) were compared and CSF samples were used to determine the best target (IS6110, MPB64, and hsp65 KDa) by qPCR. The extraction protocol using the phenol-chloroform-thiocyanate guanidine showed the best results in terms of quantification and sensitivity of PCR amplification, presenting up to 10 times more DNA than the second best protocol, the silica guanidine thiocyanate. The target that showed the best result for TBM diagnosis was the IS6110. This target showed 91% sensitivity and 97% specificity when we analyzed the results by sample and showed 100% sensitivity and 98% specificity when we analyzed the results by patient. The DNA extraction with phenol-chloroform-thiocyanate guanidine followed by IS6110 target amplification has been shown to be suitable for diagnosis of TBM in our clinical setting.

Oligella urethralis isolada em hemocultura de paciente internada no complexo HSP/UNIFESP / Oligella urethralis isolated in hemoculture from patient interned in HSP-UNIFESP complex

Primeiro isolado de Oligella urethralis em duas amostras de sangue periférico detectado por metodologia de monitoração contínua de metabolismo (sistema Bactec®) e identificado pelo sistema automatizado Phoenix® (BD System) em paciente com linfoma retroperitoneal com metástase em sistema nervoso central (SNC) no Hospital São Paulo da Universidade Federal de São Paulo (HSP/UNIFESP).

First time isolation of Oligella urethralis in two samples of peripheral blood detected by continuous metabolism monitoring methodology (Bactec 61650 system) and identified by the automatized Phoenix 61650 system (BD System) in patient with retro-peritoneal lymphoma with metastasis in the central nervous system at São Paulo hospital of Federal University of São Paulo (HSP/UNIFESP).