Comparison of polymerase chain reaction, monoclonal antibody based enzyme immunoassay, and cell culture for detection of Chlamydia trachomatis in genital specimens.

ABSTRACT

An enzyme immunoassay (EIA; AntigEnz Chlamydia; Northumbria Biologicals, Northumberland, United Kingdom) and a polymerase chain reaction (PCR) assay (Genemed Biotechnologies, San Francisco, CA) were evaluated for the detection of Chlamydia trachomatis in urogenital specimens. Of 324 specimens, 23 were positive by cycloheximide-treated McCoy's cell culture method. Of 23 culture-positive specimens, 20 and 22 were found to be positive by EIA and PCR, respectively. Among 301 culture-negative samples, 4 were found to be positive by both PCR and EIA, 2 were PCR-positive and EIA-negative, and 3 PCR-negative and culture-negative specimens were found to be positive by EIA. In comparing nonculture methods with cell culture technique, combined sensitivities of 87.0% (90.9% in men and 83.3% in women) and 95.6% (90.9% in men and 100% in women), and specificities of 97.7% (99.4% in men and 95.7% in women) and 98.0% (99.4% in men and 96.5% in women) are achieved by EIA and PCR, respectively. The PCR proved to be the more sensitive of these two nonculture methods, and it can be used for the rapid diagnosis of C. trachomatis urogenital infection.

ABSTRACT

PIP A total of 324 endocervical or urethral swab specimens were collected from patients attending the sexually transmitted diseases clinic in China Medical College and Taichung Veterans General Hospital, Taichung, Taiwan. A total of 324 urethral (from 171 men) and endocervical (from 153 women) specimens were examined by cell culture, AntigEnz Chlamydia enzyme immunoassay (EIA) (Northumbria Biologicals, Northumberland, United Kingdom), and polymerase chain reaction (PCR) for the presence of Chlamydia trachomatis. Of 324 specimens, 23 (11 from men and 12 from women) were found to be positive by the McCoy's cell culture method. Of the 23 culture-positive samples, 20 (10 from men and 10 from women) were found to be positive by both EIA and PCR, 2 (both from women) were PCR-positive and EIA-negative, and the other (from a male patient) was found to be negative by EIA and PCR. Of 301 culture-negative specimens, 292 were found to be negative by both PCR and EIA. Of the remaining specimens, 4 (1 from a male patient and 3 from female patients) culture-negative and EIA-positive and 2 (both from women) culture-negative and EIA-negative specimens were found to be positive by PCR. In addition, 3 (all from women) PCR-negative and culture-negative specimens were found to be positive by EIA. If a positive cell culture result is considered as the standard, PCR demonstrated a sensitivity of 90.9% (10/11) in men and 100% (12/12) in women, and EIA revealed a sensitivity of 90.9% (10/11) in men and 83.3% (10/12) in women. Specificities of 99.4% (159/160) in men and 96.5% (136/141) in women, and of 99.4% (159/160) in men and 95.7% (135/141) in women were obtained by PCR and EIA, respectively. Combining the data for men and women, sensitivities of 95.6% (22/23) and 87.0% (20/23), and specificities of 98.0% (295/301) and 97.7% (294/301) were achieved by PCR and EIA, respectively. The PCR proved to be the more sensitive of these two nonculture methods, and it can be used for the rapid diagnosis of C. trachomatis urogenital infection.