Semen microbiota and cytokines of healthy and infertile men

Abstract

In this study, we determined the levels of cytokine secretory inhibitors and the microbiota biofilms of semen from healthy and infertile subjects. A total of 118 clinical bacterial isolates were isolated and tested. Cytokine secretory inhibitors were determined based on the difference in cytokine content between the control and experimental samples of cell-free supernatants of isolated microorganisms. Biofilm formation was studied by determining the adhesion of microorganisms to the surface of a 96-well sterile plate and expressed as the optical density at 630 nm (OD630). Cell-free supernatants of Staphylococcus contained higher levels of secretory inhibitor of cytokines in conditionally healthy than in infertile patients. In contrast, in infertile men, the ability to reduce cytokine levels was more characteristic of Enterococcus and Corynebacterium. Seminal Staphylococcus, Corynebacterium, and Enterococcus isolated from infertile subjects showed a greater ability to form biofilms than the same bacteria isolated from healthy men. Further research is needed on this topic, since it is necessary to determine the relationships between decreased secretory inhibitors of cytokines, production of biofilms by bacteria in semen, and infertility. It is likely that the ability of microorganisms to change the concentration of cytokines and increase the level of biofilm formation in semen may be associated with minimal impairments of fertilizing ability, which are not detected using other methods.

Keywords

• biofilms; infertility; microbiota; secretory inhibitor of cytokines; semen