Performance assessment of the Allplex™ STI Essential real-time PCR assay for the diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis infections in genital and extra-genital sites.

Autor: Robinet, Sylvain, Parisot, François
Předmět:
Zdroj: Journal of Laboratory Medicine; Aug2019, Vol. 43 Issue 4, p191-200, 10p
Abstrakt: Background: Commercial kits performing Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) nucleic acid amplification tests (NAATs) for genital samples are recommended in association with culture, but the majority of real-time polymerase chain reaction (PCR) methods have not received regulatory approval for diagnostics in extra-genital sites. Since 2017, only the Hologic® Aptima Combo2 assay has an in vitro diagnostic (IVD) certification from the European Medicine Evaluation Agency. Methods: We assessed the Allplex™ STI-Essential Assay (EA) for the diagnosis of NG and CT in both genital and extra-genital sites. The performance of the extraction step was studied by means of a standard curve between the concentration of expected cultivable gonococci and the cycle threshold (Ct). Three later-generation NAATs were used as comparators, particularly to assess the specificity (Sp). Results: A relation between the gonococcal concentration, expressed as colony-forming unit (CFU) per milliliter logarithm, and the Ct was shown to be linear irrespective of the matrices (95% confidence interval [CI]). The detection limit was 10 CFU/mL, contrasting with the relatively poor sensitivity of culture due to inhibitory effects such as pH and the overgrowth of the commensal flora. NG molecular diagnostic is complex and the method comparisons showed some discrepancies when Ct was above 34. We decided to include interpretative comments on our reports on the basis of the Ct result. For CT, comparisons displayed a satisfactory agreement, and the detection limit was 50 copies/mL. Conclusions: The Seegene Allplex™ STI-EA showed acceptable performance characteristics for the detection of genital and extra-genital NG and CT. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index