Infections of the reproductive system: defense mechanisms and consequences of infectious diseases

Reproductive system infections, especially STIs (340+ million cases annually), pose a global threat to reproductive health. Male defenses include: blood-testis barrier (Sertoli cells), tight junctions of the prostate/epididymis, antimicrobial components of seminal fluid, and the antioxidant system (glutathione) that prevents oxidative damage to spermatozoa. In women, the key role is played by the multilayered epithelium of the vagina, the acidic environment (pH 3.5–4.5), the mucin barrier, interferons, and antimicrobial peptides (defensins, lysozyme). The consequences of infections are severe: in men, Chlamydia trachomatis and Neisseria gonorrhoeae cause urethritis, epididymitis, and prostatitis, leading to decreased fertility, azoospermia, and testicular damage; in women, bacterial vaginosis and STIs provoke pelvic inflammatory disease, tubal factor infertility (15–20%), ectopic pregnancy, miscarriages, and premature births. Prospects lie in developing innovative diagnostic and therapeutic methods, overcoming antibiotic resistance, and enhancing prevention.