Detection of Chlamydia trachomatis inclusions in McCoy cell cultures with fluorescein-conjugated monoclonal antibodies

Abstract

We compared two methods for identification of Chlamydia trachomatis inclusion in McCoy cell monolayers: conventional iodine staining and immunofluorescence staining with monoclonal antibodies against the species-specific major outer membrane protein antigen of C. trachomatis. Among 878 urethral and cervical specimens tested in parallel, the immunofluorescence method detected eightfold more inclusion per monolayer, identified a higher proportion of positive specimens on first passage (98 versus 62% by iodine staining; P < 0.01), and improved overall sensitivity (98% of total positive specimens detected versus 84% by iodine staining; P < 0.01). Improved sensitivity was most evident in specimens with low numbers of inclusions. Compared with conventional iodine staining, immunofluorescence staining with monoclonal antibodies improves sensitivity and offers more rapid detection of chlamydial inclusions in cell culture.