No abstract

The three main causes of vaginitis are bacterial vaginosis (BV), vulvovaginal candidiasis (VVC), and trichomoniasis (TV). Two multiplex assays are commercially available for detection of DNA from organisms associated with vaginitis: BD Affirm™ VPIII Microbial Identification Test (Affirm) and BD MAX™ Vaginal Panel (MAX VP). Here, the performance of MAX VP was compared to that of Affirm, which was considered the standard of care. Four vaginal swabs were collected from each subject with the following: BD Affirm™ VPIII Ambient Temperature Transport System (ATTS), BD MAX™ UVE Specimen Collection Kit, Hologic Aptima® Vaginal Swab Specimen Collection Kit, and BD ESwab™ collection and transport system (ESwab). Candida culture, Gram stain followed by Nugent scoring, and the Hologic Aptima® Trichomonas vaginalis assay were used for discordant analysis. Results were considered true positive if there were at least two tests positive for any vaginitis target. A total of 200 symptomatic women were evaluated in the study. The sensitivity and specificity of MAX VP for BV was 96.2% and 96.1%, respectively, compared to 96.2% and 81.6% for Affirm. The sensitivity and specificity of MAX VP for Candida spp. was 98.4% and 95.4%, respectively, compared to 69.4% and 100% for Affirm. MAX VP and Affirm showed 100% concordance for detection of TV. These results demonstrate improved accuracy of MAX VP compared to Affirm for the detection of BV and Candida spp. and no difference for detection of TV between the two tests.

The prompt and accurate identification of bacterial pathogens is fundamental to patient health and outcome. Recent advances in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) have revolutionized bacterial identification in the clinical laboratory, but uniform incorporation of this technology in the U.S. market has been delayed by a lack of FDA-cleared systems. In this study, we conducted a multicenter evaluation of the MALDI Biotyper CA (MBT-CA) System (Bruker Daltonics Inc, Billerica, MA) for the identification of aerobic gram-negative bacteria as part of a 510(k) submission to the FDA. A total of 2,263 aerobic gram negative bacterial isolates were tested representing 23 genera and 61 species. Isolates were collected from various clinical sources and results obtained from the MBT-CA System were compared to DNA sequencing and/or biochemical testing. Isolates that failed to report as a "high confidence species ID" [log(score) ≥2.00] were re-tested using an extraction method. The MBT-CA System identified 96.8% and 3.1% of isolates with either a "high confidence" or a "low confidence" [log(score) value between 1.70 and <2.00] species ID, respectively. Two isolates did not produce acceptable confidence scores after extraction. The MBT-CA System correctly identified 99.8% (2,258/2,263) to genus and 98.2% (2,222/2,263) to species level. These data demonstrate that the MBT-CA System provides accurate results for the identification of aerobic gram-negative bacteria.

The Bruker MALDI Biotyper CA System accurately identifies most clinically important bacteria and yeasts and has optional processing methods to improve isolate characterization.

No abstract