[Detection of Chlamydia trachomatis in routine clinical practice: increased sensitivity of cell culture in comparison...

Recently, direct immunofluorescence staining has been reported as a new tool for detection of Chlamydia trachomatis. This assay is based on monoclonal antibodies directed against a protein present in all serological variations of Chlamydia known to date. In order to evaluate whether immunofluorescence staining could substitute for the time-consuming, expensive tissue culture technique, urethral and cervical swabs of 131 patients treated for sterility were examined for infection with Chlamydia by both methods. The tissue culture technique, based on cultivation of Chlamydia in mammalian cells, was regarded as 100% sensitive and specific. Employing this method, we demonstrated infection with Chlamydia in 20 patients (15.3%). Colonization of both, cervix and urethra was found in 11.5%, whereas solitary colonization of cervix and urethra was found in 2.3 and 1.5% respectively. However, the immunofluorescence assay applied ("Micro-Trak", Syva Company) showed positive results in only 6 out of 20 cases as determined by tissue culture, thus yielding a sensitivity of 30%. Out of 111 patients with negative results in the tissue culture, 108 were detected by immunofluorescence staining, amounting to a specificity of 97.3%. With special regard to the low sensitivity of the direct immunofluorescence assay, our results indicate a superior, yet unequalled role of the tissue culture technique for detection of Chlamydia trachomatis.