In Vivo and In Vitro Impairment of Human and Ram Sperm Nuclear Chromatin Integrity by Sexually Transmitted Ureaplasma urealyticum Infection1

Abstract

The incidence of Ureaplasma urealyticum infection in the semen of infertile men is variable (7%-42%). Evidence has accumulated through routine semen analysis to suggest that this infection can cause embryo loss without necessarily affecting sperm quality. The aim of this study was to specifically investigate the effects of U. urealyticum infection on sperm chromatin stability and DNA integrity, which are known to be correlated to pregnancy outcome. Sperm cells isolated from human semen infected in vivo with U. urealyticum exhibited a low percentage of stable chromatin as determined by nuclear chromatin decondensation assay (42% +/- 4.8%, n = 8) and a high percent of denatured DNA as determined by sperm chromatin structure assay (60.9% +/- 9.1%, n = 7). After doxycyclin treatment, a significant improvement in both parameters was observed (73.7% +/- 3.6%, P: < 0.001 and 30.1% +/- 3.5%, P: < 0.008, respectively). Sperm cells infected in vitro exhibited higher rates of viability and motility than uninfected cells. In contradistinction, U. urealyticum caused significant dose- and time-dependent chromatin decondensation and DNA damage. The percentage of human sperm cells with denatured DNA increased significantly by 54.9% +/- 23.9% and 47. 9% +/- 12.1%, after 30 min infection with serotypes 8 and 3, respectively, at a multiplicity of infection of 100 ureaplasmas per sperm compared with uninfected control cells. The damage to DNA was significantly more pronounced in infected ram sperm (180.9% +/- 21. 5%). These results indicate that preserved sperm activity post U. urealyticum infection resulted in damage to paternal DNA, although a high fertilization rate was maintained, and embryonic development may, therefore, be impaired.

The Severity of Chorioamnionitis in Pregnant Sheep Is Associated with In Vivo Variation of the Surface-Exposed Multiple-Banded Antigen/Gene of Ureaplasma parvum1

“…However, spermatozoa infected with ureaplasmas in vivo [14] and in vitro [16] have higher motility levels, and ureaplasmas adherent to the surface of spermatozoa could therefore gain access to the female upper genital tract and colonize the endometrium prior to implantation and the amniotic fluid persistently throughout pregnancy.…”

<i>Ureaplasma urealyticum</i> and <i>Mycoplasma hominis</i> in Men Attending for Routine Semen Analysis

“…Earlier studies indicate that mycoplasmas lead to inflammatory reactions in the urethra, prostate and epididymis [1][2][3]. Likewise, conclusive evidence indicates that mycoplasmas affect sperm motility [4], chromatin integrity [5] and spermatogenesis [6] decreasing the sperm function.…”

Role of genital tract infections and inflammatory processes in male infertility

“…These agents colonize the vagina of women who have contact with several partners. In the in vitro fertilization systems, the presence of U. urealyticum in either the seminal material or the female genital tract leads to an increase in the failure rate (Montagut et al, 1991;Reichart et al, 2000). Ureaplasmas are also etiological agents of male infertility (Radhonane et al, 2007).…”