Normal flora of genitourinary tract
Normal flora of Urinary tract
- In healthy individual kidney, urinary bladder and ureter are sterile. Furthermore urine collected in urinary bladder is also sterile.
- Urethra of both male and female have normal flora. Surrounding skin microflora gradually ascends up through urethra and get established there. But frequent passing of urine removes microorganisms so that they cannot reach urinary bladder.
- Only lower portion of urethra contains normal flora and upper portion contains very few or no microflora.
Urethra:
- contains mostly gram positive bacteria such as;
- Staphylococcus epidermidis
- Streptococcus faecalis,
- non pathogenic Neisseria species
- Corynebacterium spp
- *male urethra is relatively sterile than female urethra
- Gram negative rods are opportunistic pathogen causing UTI
Normal flora of genital tract:
- Internal organs such as testis, ovary, ureter etc are sterile in healthy individuals.
- Urethra and vagina contains microflora.
vagina:
- Normal flora of vaginal tract depends upon age and menstrual cycle.
After puberty and before menopause:
- Lactobacillus is predominant
- During this period ovary is active and produces large amount of glycogen. Lactobacillus ferments glycogen to form lactic acid maintaining pH highly acidic (4.4-4.6). at this pH only acid tolerant Lactobacillus can grow.
Before puberty and after menopause:
- vagina become less acidic.
- At this pH condition other commensals inhabits the vagina such as:
- Staphylococcus,
- Viridans Streptococci
- MicrococcusC
- orynebacterium spp
- E. coli
- Enterococci