Padronização do diagnóstico por PCR tempo real para meningite meningocócica e teste de amostras clínicas de liquor de crianças com suspeita de meningoencefalite

Abstract

Bacterial meningitis is responsible for high morbidity and mortality in children, despite the latest advances in diagnostic methods, the antimicrobial treatment and prophylactic measures. Due its, severity and high potential for causing epidemics, bacterial meningitis is a compulsory notification disease and the invvestigation is mandatory i. The bacterial etiological agents that most commonly cause meningitis are Haemophilus influenzae b (Hib), Streptococcus pneumoniae (pneumococcus) and Neisseria meningitidis (meningococcus). The prognosis of meningitis depends on the precocity of diagnosis, therapy and the support measures. A rapid and sensitive diagnosis is of great importance for the identification of the involved etiological agent. In this study we developed a rapid e economical efficient diagnosis of l Neisseria meningitidis (meningococcus) by qPCR (quantitative polymerase chain reaction). The technique of molecular biology consists of an in vitro amplification reaction of DNA in real time. This reaction combines a PCR methodology with a mechanism of detection and quantification by fluorescence. The analysis allows that the process of amplification, detection and quantification of DNA could be performed in a single step, speeding the results, reducing the risk of contamination and obtaining higher precision. A total of 204 samples of cerebrospinal fluid from hospitalized children of the Hospital João Paulo II with clinical suspicion of meningoencephalitis were analyzed by qPCR. The positivity of the test was 2.9% and 1.9% were not detected in other tests. The test was specific and was not able to detect up to 10,000 CFU / mL. The proposed method is without the stage of DNA extraction which represents a risk of contamination and a step were nucleic acid loss could occur. The test is fast compared to conventional tests.