Microbial Diseases of the Urinary and Reproductive Systems Microbes usually enter the urinary system through the urethra Microbes usually enter the reproductive system through the: Vagina (females)or urethra(males)Microbial Diseases of the Urinary and Reproductive Systems • Microbes usually enter the urinary system through the urethra • Microbes usually enter the reproductive system through the: • Vagina (females) or urethra (males)