Performance evaluation of a DNA chip assay in the identification of major genitourinary pathogens.

BACKGROUND

To prevent the recurrence of genitourinary infections and to reduce the risks of their complications, accurate and rapid diagnosis are required. STDetect® Chip is a DNA chip which allows for the simultaneous detection of 13 major genitourinary pathogens in a single vaginal swab or urine specimen. We evaluated the analytical performance of the STDetect® Chip for detecting target pathogens that commonly cause genitourinary infections.

METHODS

The target pathogens of the STDetect® Chip are Chlamydia trachomatis, Candida albicans, Enterococcus faecalis, Gardnerella vaginalis, Mycoplasma hominis, Neisseria gonorrhoeae, Mycoplasma genitalium, Ureaplasma urealyticum, Staphylococcus aureus, Klebsiella pneumoniae, Trichomonas vaginalis, and Herpes simplex virus types 1 and 2. Performance of the STDetect® Chip for the detection of target pathogens was evaluated comparing with the result of direct sequencing and conventional multiplex PCR assay. And precision tests for STDetect® Chip were performed with quality control materials.

RESULTS

The STDetect® Chip showed high sensitivities (95.1%-100%), specificities (93.4% to 100%), concordance rates (95.0%-100%), positive predictive values (69.8%-100%), and negative predictive values (93.1%-100%) in its identification of 13 target pathogens. The STDetect® Chip had a particularly excellent concordance rate (96.5%) for the 4 major pathogens, C. albicans, G. vaginalis, M. hominis, and U. urealyticum, compared with direct sequencing. Comparing to multiplex PCR assay, STDetect® Chip showed better sensitivity for detecting M. hominis (97.0% vs. 54.5%) and U. urealyticum (93.2% vs. 65.9%). In precision tests, coefficients of variations for signal intensities were ranged from 11.2% to 26.2%.

CONCLUSION

The STDetect® Chip showed excellent analytical performance, and its result was in good agreement with that obtained by direct sequencing.