Evaluation of Chlamydia trachomatis and Neisseria gonorrhoeae detection in urine, endocervical, and vaginal specimens by a multiplexed isothermal thermophilic helicase-dependent amplification (tHDA) assay.

We have developed a new research assay that combines sequence-specific sample preparation and isothermal amplification for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae infections. The assay targets both the omp gene and the cryptic plasmid of C. trachomatis and the multicopy opa gene of N. gonorrhoeae, which are amplified and detected in a single reaction. We evaluated the ability of the assay to detect C. trachomatis and N. gonorrhoeae infections in first-catch urine, swab, and liquid-based cytology samples. Total agreement between the new assay and APTIMA Combo 2 varied between 95.3% and 100%, depending on the sample type and target detected. Total agreement between the new assay and BD ProbeTec varied between 96.7% and 100%, depending on the sample type and target detected. The assay has a simple work flow, and endpoint results can be achieved in 3 h, including sample preparation. The assay described here was evaluated for research use and was compared to commercially available assays.