Infection and phagocytosis: analysis in semen with transmission electron microscopy

Chlamydia trachomatis is the most prevalent bacterial pathogen causing sexually transmitted disease in the world. Also, several mycoplasmas species have been isolated from the human genital tract. There is conflicting evidence regarding the influence of infections with C. trachomatis and mycoplasmas on male infertility, and their exact role in development of this pathology is still debated. Transmission electron microscopy can be of great help in the study of the cellular mechanisms that underlie this male infertility condition. This is especially obvious when the small size of C. trachomatis and mycoplasmas is considered. On the other hand, there is a correlation between genital infection with these bacteria and the appearance of leukocytes in semen. There is controversy on the significance of leukocytes in semen. Finally, reports regarding phagocytosis of spermatozoa by epithelial cells of the male genital tract are controversial. In this article are presented ultrastructural findings that we encountered in semen samples of infertile men infected with C. trachomatis and/or mycoplasmas: a) structural damage of spermatozoa, b) phagocytosis of damaged spermatozoa by leukocytes, c) destruction of bacteria by leukocytes, d) persistence of bacteria in leukocytes, and e) phagocytosis of damaged spermatozoa and leukocytes by epithelial cells of the genital tract.