Mycoplasmic localization patterns on spermatozoa from infertile men.

Two mycoplasmas have been observed with increasing frequency in patients with genitourinary disorders: Mycoplasma hominis and Ureaplasma urealyticum. Mycoplasma cells of both these species have been demonstrated to be capable of attaching to human spermatozoa of infertile patients. The mechanisms for the association of infertility and mycoplasma infection have not been established. The main objective of this article was to explain the significance of some morphologic features of spermatozoa of patients with unexplained infertility using light and electron microscopy. These studies and quantitative analysis of ureaplasmas in the semen indicate that at least two patterns can be seen. Frequently, sphere-shaped particles adhering mainly to the midpiece of spermatozoa were detected. In a second, more complex pattern ureaplasmas were seen inside a swollen zone on the midpiece, which suggests that the infection does not occur in the urethra, but at another unknown site. Furthermore, the sphere-shaped particles cannot be associated with ureaplasmas because their titers in the semen of infertile patients were much lower than those expected.