Immuno-gold Labelling of Chlamydia trachomatis’ Elementary Bodies

Background: Chlamydia trachomatis is considered as an important cause of preventable sexually transmitted diseases, worldwide. It is known to be of an obligate intracellular nature and enters its target cells via an endocytic process. As major outer membrane protein (MOMP) is one of the main candidates for the attachment and entry of chlamydia to the host cells, we have tried to label the epitopes by using different techniques. Materials and Methods: McCoy cells were experimentally inoculated with 104 elementary bodies (EBs) followed by 24 hours incubation at 37°C. The infected cells were then processed for direct fluorescent antibody (DFA) and transmission electron microscopy (TEM) using anti- MOMP antibody and pre- and post-embedded labelling techniques. Results: DFA was able to detect 11/11 (100%) of the infected cells. These values were recorded as 9/11 (81.81%) and 8/11 (72.72%), using pre- and post-embedded techniques, respectively. Conclusion: MOMP is proposed to be one of the most important adhesion molecules for chlamydial attachment and entry into host cells.