<p>The male urethra serves as an ascending route for infection to access the lower urinary tract and the genital tract. The male genital tract &mdash; composed of the prostate, ejaculatory ducts, seminal vesicles, vas deferens, epididymis, and testicles &mdash; is normally sterile. This sterility is maintained by the mechanical action of urination and ejaculation, and more importantly, by the antibacterial effect of a zinc-containing polypeptide secreted by the prostate.</p>