Multicentric comparative assessment of the Bio-Evolution® Toxoplasma gondii detection kit with eight laboratory-developed PCR assays for the molecular diagnosis of congenital toxoplasmosis.

[congenital toxoplasmosis]

Detection of Toxoplasma gondii in amniotic fluid is an essential tool for the prenatal diagnosis of congenital toxoplasmosis and today is essentially based upon PCR . Although some consensus is emerging , this molecular diagnosis suffers from a lack of standardization and an extreme diversity of laboratory-developed methods . Commercial kits for the detection of T . gondii by PCR have been recently developed and offer certain advantages ; however they must be assessed in comparison with optimized reference PCR assays . The present multicentric study aimed at comparing the Bio-Evolution ® Toxoplasma gondii detection kit with laboratory-developed PCR assays set up in eight proficient centers in France . The study compared 157 amniotic fluid samples and found a concordance of 99 % and 100 % using 76 T . gondii-infected samples and 81 uninfected samples , respectively . Moreover , taking into account the classification of the European Research Network on Congenital Toxoplasmosis , the overall diagnostic sensitivity of all assays was identical and calculated at 86 % (54 /63 ); specificity was 100 % for all . Finally , the relative quantification results were in good agreement between the kit and the laboratory-developed assays . The good performances of this commercial kit are probably in part linked to the use of a number of good practices : detection in multiplicate , amplification of the repetitive DNA target 're p 529 ', use of an internal control for the detection of PCR inhibitors . The only drawbacks noted at the time of the study were the absence of Uracil-N-glycosylase , as well as small defects in the reliability of the production of different reagents .