The urogenital system combines urinary and reproductive functions, with unique anatomy and microbiota for males and females. This complex system has various defenses against microbial invasion, including urine flow, low pH, and physical barriers.

Urogenital infections can manifest in diverse ways, from UTIs to STIs. Understanding the signs and symptoms of these infections is crucial for early detection and treatment. The urogenital microbiome plays a vital role in maintaining health and preventing infections.

Anatomy and Microbiota of the Urogenital Tract

Anatomy of urogenital systems

• Male urogenital system anatomy and function
  • Penis serves as external genitalia for sexual intercourse and urination
  • Testes produce sperm and testosterone hormone
  • Prostate gland produces fluid that forms part of semen
  • Urethra carries both urine and semen out of the body (dual function)
• Female urogenital system anatomy and function
  • Vulva includes external genitalia such as labia and clitoris
  • Vagina is a muscular canal that connects external genitalia to the cervix
  • Cervix is the lower part of the uterus, connecting vagina and uterus
  • Uterus is a muscular organ where fetal development occurs during pregnancy
  • Fallopian tubes transport eggs from ovaries to the uterus
  • Ovaries produce eggs and female hormones like estrogen and progesterone
• The urogenital system comprises both the urinary system and reproductive system

Microbial invasion of urogenital defenses

• Normal microbiota of male urogenital system
  • Urethra contains Streptococcus, Staphylococcus, Corynebacterium, and anaerobic bacteria
  • Male urogenital system has low microbial diversity compared to the female system
• Normal microbiota of female urogenital system
  • Vagina is dominated by Lactobacillus species which maintain a low pH and prevent pathogen growth
  • Other bacteria present include Streptococcus, Staphylococcus, Enterococcus, and anaerobic bacteria
  • Female urogenital system has higher microbial diversity compared to the male system
• Urogenital defenses against microbial invasion
  • Urine flow provides mechanical flushing of microorganisms out of the system
  • Low pH of the vagina inhibits growth of pathogenic microbes
  • Mucus traps and prevents microorganisms from adhering to epithelial cells
  • Antimicrobial peptides secreted by epithelial cells kill or inhibit microorganisms
  • The epithelium acts as a physical barrier against pathogens
• Mechanisms used by microbes to bypass urogenital defenses
  1. Adhesion using adhesins to attach to epithelial cells and resist mechanical flushing
  2. Biofilm formation creates protective extracellular matrices, increasing resistance to antimicrobials
  3. Urease production by some bacteria breaks down urea in urine, increasing pH and facilitating survival
  4. Evasion or suppression of the host immune response allows for persistent infection

Urogenital Microbiome and Host Interactions

• The urogenital microbiome plays a crucial role in maintaining health
• Hormones influence the composition of the urogenital microbiome
• The immune system interacts with the microbiome to maintain balance
• Disruptions in the microbiome can lead to various urogenital conditions

Signs of urogenital infections

• Urinary tract infections (UTIs) signs and symptoms
  • Dysuria is pain or burning sensation during urination
  • Frequency refers to frequent urge to urinate
  • Urgency is a sudden, strong need to urinate
  • Hematuria is the presence of blood in the urine
  • Suprapubic pain occurs in the lower abdomen
• Bacterial vaginosis (BV) signs and symptoms
  • Thin, grayish-white vaginal discharge
  • Fishy odor especially noticeable after sexual intercourse
  • Itching or burning sensation in the vagina
• Yeast infections (Candidiasis) signs and symptoms
  • Thick, white, cottage cheese-like vaginal discharge
  • Itching, burning, or soreness in the vagina and vulva
  • Redness and swelling of the vulva
• Sexually transmitted infections (STIs) signs and symptoms
  • Chlamydia and Gonorrhea
    • Abnormal vaginal discharge
    • Burning sensation during urination
    • Pelvic pain
    • Often asymptomatic, especially in males
  • Genital herpes
    • Painful, fluid-filled blisters on the genitals or rectum
    • Fever and body aches accompany outbreaks
  • Human Papillomavirus (HPV)
    • Genital warts appear as small, flesh-colored bumps on the genitals or anus
    • HPV infection is often asymptomatic