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.