Retrospective study of Chlamydia trachomatis using the polymerase chain reaction on archival Papanicolaou-stained cytologic smears.

OBJECTIVE: To detect chlamydial DNA on archived Papanicolaou-stained (Pap) smears using the polymerase chain reaction (PCR) technique. STUDY DESIGN: A PCR assay was designed to identify chlamydial DNA using consensus sequences unique to the genus Chlamydia in the 16S rRNA gene. This assay produced a 109 base pair product containing a single Pvu II restriction site. One hundred cervicovaginal Pap smears from a teen clinic population were processed for DNA isolation and PCR. Amplifiable DNA was isolated from 93 of the 100 cases as determined by a human growth hormone gene. These specimens were subjected to chlamydial PCR. RESULTS: PCR analysis of the 93 samples yielded 6 that were positive for the chlamydial 16S rRNA sequence. The six positive chlamydial amplicons were purified and subjected to Pvu II restriction enzyme analysis to validate their identity. The analysis confirmed the identity of the products, as a single Pvu II restriction site resulted in 41 base pair and 68 base pair products, as predicted. CONCLUSION: PCR testing for Chlamydia trachomatis can be performed on DNA isolated from archival Pap smears. Using this methodology, 6.5% of young women in our teen clinic population were positive for chlamydial DNA.