Performance verification and clinical evaluation of the NAP-Fluo Cycler system for detecting five genital tract pathogens based on microfluidic technology

Introduction

Sexually transmitted infections (STIs) are among the most common infectious diseases worldwide, often leading to coinfections. Timely detection of genital tract pathogens in at-risk populations is crucial for preventing STIs. We evaluated the NAP-Fluo Cycler System, an innovative microfluidic nucleic acid detection platform, for its ability to simultaneously identify Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Ureaplasma urealyticum (UU), Mycoplasma genitalium (MG), and Mycoplasma hominis (MH) in urethral or cervical secretions.

Materials and methods

The limits of detection (LODs), repeatability, specificity, and interference resistance of the system were evaluated using standard strains, a panel of 24 pathogens, and seven interferents. We used the system to analyze 302 clinical samples and compared the results with those of five approved commercial reference kits.

Results

The system achieved LODs of 500 IFU/mL, 500 CFU/mL, and 500 CCU/mL for CT, NG, and UU/MG/MH, respectively, demonstrating high stability (coefficient of variation <1.1 %), specificity, and resistance to interference. Among 302 clinical samples, 237 tested positive with single, dual, and triple infection rates of 35.6 %, 16.2 %, and 3.0 %, respectively. The reference kits detected 138 positive samples. The concordance rates with commercial reference kits were 100 % for UU, NG, and MH; 94.85 % for CT; and 80.00 % for MG.

Conclusions

This system offers a streamlined, rapid, and multiplex detection method that reduces testing time and complexity. Although it performs well with pure strains, it has limitations when using clinical samples of CT and MG, suggesting the need for further refinement before its widespread use in the clinic.