Almost 80% of urinary tract infections (UTIs) in adults are causing by Escherichia coli (E. coli). An e.coli bacterium is normally present in the colon.
Urinary tract infection causes
Normally, urine is sterile and usually free of bacteria, viruses, and fungi. However, it does contain fluids, salts, and waste products.
An infection occurs when microorganisms, usually bacteria from the digestive tract, enters into the opening of the urethra and begins to multiply.
- Almost 80% of urinary tract infections (UTIs) in adults are causing by Escherichia coli (E. coli). An e.coli bacterium is normally present in the colon and may pass into the urethral opening from the skin around the anus and genitals. Women are more susceptible to UTI because their urethral opening is nearer to the anus and their urethra is shorter, so bacteria easily get in to the bladder.
- Other bacteria that may cause urinary tract infections include; Staphylococcus saprophyticus (5 to 15% of cases), Chlamydia trachomatis, and Mycoplasma hominis. Chlamydia trachomatis or mycoplasma hominis can transmit to their partner during sexual intercourse, causing UTI.
- Sexual intercourse may trigger UTI in some women, for unknown reasons.
- Urinary catheterization (i.e., to drain urine from the bladder by inserting a small tube through the urethra) can also induce UTI by introducing bacteria into the urinary tract.
- In infants, bacteria from soiled diapers can enter the urethra and cause UTI.
- E. coli may also enter the urethral opening when young girls do not wipe from the front to back after a bowel movement.