High-throughput multistrain polymerase chain reaction quantification of Chlamydia trachomatis from clinical and preclinical urogenital specimens.

Chlamydia trachomatis (CT) is the most prevalent sexually transmitted bacterial pathogen worldwide and causes severe reproductive tract infections. Currently, nucleic acid amplification tests (NAATs) are the gold standard for clinical diagnosis, but most NAATs are labor intensive and limited to specific CT serovars. We developed and validated a quantitative polymerase chain reaction (qPCR) assay that reproducibly detected CT serovars D, E, F, Ia, and Chlamydia muridarum over a linear range of 2 log(10) to 10 log(10) genomes with low coefficients of variation from both experimental and human urine samples. CT DNA loads from human vaginal, endocervical, and male urethral swabs correlated well with the BD ProbeTec ET assay (Becton Dickinson Diagnostic Systems, Franklin Lakes, NJ) run in parallel. In a preclinical microbicide evaluation, C. muridarum DNA loads in mouse swabs and tissues correlated well with an immunofluorescence assay. The optimized qPCR system provided enhanced sensitivity and facilitated the quantitative evaluation of clinical and experimental preclinical samples for anti-CT therapeutic and microbicide evaluation.