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

• The STDetect® Chip showed excellent analytic performance in its identification of 13 target pathogens.
• Comparing to multiplex PCR, STDetect® Chip showed better sensitivity for detecting M. hominis and U. urealyticum.
• In precision tests, CV values for signal intensities were ranged from 11.2% to 26.2%.

BackgroundTo 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.MethodsThe 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.ResultsThe 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%.ConclusionThe STDetect® Chip showed excellent analytical performance, and its result was in good agreement with that obtained by direct sequencing.