Ultrastructural observations on the entry of Chlamydia trachomatis into human spermatozoa.

Chlamydia trachomatis infections are an important problem in human reproduction and family planning. In this study, the significance of chlamydial infection in male infertility and artificial insemination has been investigated. Electron microscope observations on male ejaculates have revealed the presence of the elementary and reticulate body forms of C.trachomatis in spermatozoa. Furthermore, the entry of the elementary body into the human spermatozoon head has been demonstrated. After the passage of the infectious elementary body into the nucleus, all stages of reticulate body formation in the head of the spermatozoon were detected. According to ultrastructural findings, C.trachomatis not only adhered to but also penetrated into the tail structure. Thus two different functional and morphological forms of C.trachomatis can infect and be transmitted by spermatozoa and may cause infertility.