This study evaluated the performance characteristics of a new research use transcription-mediated amplification (TMA) assay for detection of ribosomal RNA from Treponema pallidum (Tp). Analytical sensitivity determined using dark field quantitated Tp was 1.4 organisms/ml (95% CI: 0.7-6.33). Dilution of Tp IVT RNA in STM yielded 100% positivity (n=3) at 10 copies/ml (4 copies/reaction). Analytical specificity testing of non-target microorganisms (N=59), including the closely related non-syphilis treponemes T. denticola and T. phagedenis, yielded 0% positivity. TMA testing of mucosal swab specimens collected from men who have sex with men (MSM) attending a sexually transmitted disease clinic yielded 1.8% (17/944) TMA positive results. A collection of 56 serum specimens obtained from a separate cohort of patients with known rapid plasma reagin (RPR) status and syphilis clinical diagnosis were 19.6% (11/56) TMA positive overall, 29.7% (11/37) positive among subjects with syphilis diagnosis, including 8 (36.3%) of 22 persons with primary or secondary syphilis, 2 (20%) of 10 persons with early latent syphilis and 1 (20%) of 5 persons with late latent or unstaged syphilis. None (0%) of 18 RPR positive sera from patients with a history of treated syphilis was TMA positive. These results show TMA is an analytically sensitive and specific method for detection of Tp rRNA and is compatible with serum specimens in addition to pharyngeal and rectal mucocutaneous swab specimens. Automated real time TMA testing for T. pallidum may be useful as an adjunctive method with serology for screening and diagnostic testing of selected patient populations for syphilis.

Background Candida auris is an emerging fungus that presents a serious global health threat. It is often multidrug-resistant and difficult to identify with standard laboratory methods. C. auris outbreaks have been associated with high mortality in healthcare settings. Rapid and accurate screening for C. auris is crucial for preventing transmission and directing treatment. This study evaluated a new fully automated, lab-developed real-time PCR assay for the detection of C. auris. Methods Nasal swabs collected with Aptima Multitest swabs were used as a representative clinical matrix to evaluate C. auris detection using the Open Access™ functionality on the Panther Fusion® instrument. It provided fully automated nucleic acid extraction, amplification, and detection workflow. The primers and probe are published sequences designed by CDC which target the internal transcribed spacer 2 (ITS2) region of the C. auris ribosomal RNA gene. Analytical studies evaluated assay sensitivity, specificity, and inclusivity. An internal control is also included to ensure assay validity. Results The limit of detection (≥ 95% detection rate) of the Candida auris real-time PCR assay is 5 CFU/mL for nasal swabs. Eleven C. auris strains from CDC clinical isolates were reactive for inclusivity study. No cross reactivity or interference was observed from 60 microorganisms of closely related yeast, bacteria and viruses typically present in skin and groin samples. Conclusion A fully automated and high throughput real-time PCR test for C. auris with internal control, utilizing primers and probe sequences published by CDC, demonstrated excellent sensitivity, specificity, and inclusivity. This lab developed test (LDT) provides a rapid, sensitive, and scalable method for detection of C. auris. The results are crucial for timely detection, transmission prevention and targeted treatment of the multidrug-resistant C. auris. Disclosures All Authors: No reported disclosures.