Avaliação dos métodos sorológicos e da técnica de Nested-PCR utilizando o iniciador GRA7 na detecção do Toxoplasma gondii no líquido amniótico de gestantes

摘要

Toxoplasmosis is the etiologic agent protozoan Toxoplasma gondii and usually cause asymptomatic infection in immunocompetent individuals. However, congenital transmission can lead to serious and death, representing a serious public health problem. In pregnant patients reactive to IgM anti-T. gondii is recommended molecular diagnosis using amniotic fluid qualitative PCR method with the primer B1. However, the diagnosis using this approach can be inefficient mainly for detection of hybrid strains found in Latin America. In this context, the objective of this study was to evaluate the effectiveness of serological methods and nested PCR technique using the primer GRA7 the detection of Toxoplasma gondii congenital transmission. The study was performed in 71 pregnant women seen at the Anita Garibaldi Health Center (CSAG), Macaíba-RN in the period 2011 to 2015, aged gestational variables and age group 15-49 years, subjected to routine procedures during the examination prenatal the case, therefore, a study of cross-sectional observational design accuracy. Samples of peripheral blood and amniotic fluid was collected. Initially it performed the serological diagnosis of toxoplasmosis with the help of ELISA and indirect immunofluorescence (IIF) for the detection of IgG and IgM anti-T. gondii. Subsequently, patients showed reactive serologic tests for IgM were selected to perform the nested PCR technique using the RE and GRA7 initiators. The seroreactivity detected by the presence of anti-IgG and IgM. T. gondii by the ELISA and IFA techniques were respectively 91.55% and 14.08%, 76.06% and 5.63%. Total positivity for IgM when combined the techniques of ELISA and IFA was 15.49% (11/71). However, analysis of positive using the nested PCR was 0% (0/11), 9,09% (1/11) and 54.5% (6/11) using the primers RE, B1 and GRA7 respectively. The results indicate that the proposed GRA7 initiator is more efficient in the detection of T. gondii in amniotic fluid B1 and RE primer, when using the nested PCR technique.