Molecular testing (strand displacement assay) for identification of urethral gonorrhoea in men: can it replace culture as the gold standard?

Abstract

The objective was to evaluate the performance of Becton Dickinson's BD Probe Tec(TM) (BDPT) strand displacement amplification (SDA) test for the detection of Neisseria gonorrhoeae on urethral specimens from men with urethritis compared with conventional culture and to show that SDA improves the diagnostic yield of gonorrhoea infections (GC). Anonymized retrospective testing of stored urethral swab samples from men attending genitourinary services in East London was performed using SDA. The prevalence of GC culture positive infections in this sample was 20/152 (13%). The sensitivity, specificity, positive predictive value and negative predictive value for the BDPT-SDA system compared with culture were 100%, 95%, 77% and 100%, respectively. In this study population, the BDPT-SDA assay was a highly sensitive and specific test for the diagnosis of N. gonorrhoeae from urethral swabs in men. Therefore, SDA can be used to complement culture in the diagnosis of N. gonorrhoeae infection. No ethics committee approval was obtained as all samples were anonymized.