A-268 Evaluation of a Real-Time Multiplex PCR Assay for Simultaneous Detection of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis in Urine Specimens

Abstract

Abstract Background Infections with Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) are among the most prevalent and treatable sexually transmitted diseases in the US. Currently, most available testing methods require patient samples to be split between CT/NG and TV assays. Here, we evaluate performance characteristics of the Seegene Novaplex STI Essential Assay, a real-time multiplex polymerase chain reaction assay for concurrent amplification and detection of multiple pathogens including CT, NG, and TV. Methods To prepare urine samples for extraction, 1 mL of each sample was centrifuged at 13 000 rpm for 15 min. The supernatant was discarded and the pellet was rehydrated in 190 µL of saline. Nucleic acid extraction was performed on a CyBio® FeliX liquid handler (Analytik Jena, Germany) using MagMAX™ Viral/Pathogen Nucleic Acid Isolation Kit (Thermo Fisher Scientific, MA). PCR amplification and detection were performed using Seegene Novaplex STI assay (Seegene Inc, South Korea) on a CFX96™ System (Bio-Rad Laboratories, CA). The assay utilizes Seegene MuDT™ technology that allows detection of multiple targets in a single channel without melting curve analysis. For method validation, precision studies were performed within-run and over 5 days. Limits of detection were verified by spiking known negative urine samples with CT/NG standards from Exact Diagnostics (Bio-Rad Laboratories, CA) and TV standards from ZeptoMetrix® (Antylia Scientific, IL). Method comparison was carried out by extracting and analyzing split patient urine samples against cobas® CT/NG assay (Roche Diagnostics, IL) and Solana® Trichomonas assay (Quidel, CA) performed by a reference laboratory. Additional accuracy studies were performed by spiking 20 negative patient samples with variable concentrations of the three pathogens. Results Within-run and between-day precision studies demonstrated consistent and reproducible results for all pathogens. Limit of detection was established at 10 copies/mL for CT and NG and 10 cells/mL for TV. Results of the spike-and-recovery studies were consistent with expected results for all three targets across evaluated concentrations. Patient correlation studies demonstrated 100% agreement with results obtained by the reference laboratory for both NG (32 total samples, 11 positive) and TV (22 total samples, 4 positive), and 96% agreement for CT (29 total samples, 10 positive). Conclusion The Seegene Novaplex STI Essential Assay offers a rapid and reliable method for detecting CT, NG, and TV in urine samples. The capability of the assay to detect multiple targets in a single sample well improves efficiency and turnaround time.