Evaluation of the Abbott RealTime™ CT assay with the BD ProbeTec™ ET assay for the detection of Chlamydia trachomatis in a clinical microbiology laboratory

The Abbott RealTime™ CT assay (Abbott Molecular, Des Plaines, IL) was evaluated by testing male urine samples (n = 204) and female urine samples (n = 207) with matched endocervical swabs (n = 207) collected from patients attending the Genito-Urinary Infectious Disease Clinic, St. James's Hospital, Dublin, Ireland. Results were compared with the BD ProbeTec™ ET assay (Becton Dickinson, Sparks, MD). Both assays were performed within 3 days of specimen collection. Samples positive with 1 or other assay were subjected to discrepant-based analysis using 2 additional assays, an “in house real-time polymerase chain reaction [PCR]” and a “nested PCR with amplicon sequence detection”. After resolution of discordant results, the Abbott RealTime™ CT assay demonstrated greater clinical sensitivity than the BD ProbeTec™ ET assay for the detection of Chlamydia trachomatis (CT) in all sample types. Both assays demonstrated acceptable analytic sensitivity with detection limits of 22 and 33 cryptic plasmid copies/reaction, respectively. The sensitivity of the Abbott RealTime™ CT assay combined with automated throughput establishes this assay as a quality diagnostic tool.