Detection of experimental Chlamydia trachomatis eye infection in conjunctival smears and in tissue culture by use of fluorescein-conjugated monoclonal antibody.

The immunofluorescent staining of conjunctival cytology smears with an antichlamydial monoclonal antibody is a new method for the detection of chlamydial eye infection. Using a monkey model of chlamydial eye infection, we compared the monoclonal antibody staining cytology with the established methods of Giemsa-stained cytology and chlamydial culture with cycloheximide-treated McCoy cells. Compared with either culture or monoclonal antibody-stained cytology, Giemsa cytology had a low sensitivity (30 and 24%, respectively) but was highly specific (100% in each case). Compared with culture, monoclonal antibody-stained cytology was highly sensitive (94%) but appeared to lack specificity (70%). However, examination of the changes in identification rates with time suggested that monoclonal antibody-stained cytology may be even more sensitive than culture and detect lower levels of infection. This study showed that monoclonal antibody-stained cytology of conjunctival smears might be a rapid, efficient, and inexpensive method of diagnosing ocular chlamydial infection.