Urinary tract infections (UTIs) are most commonly caused by bacteria and can result in a burning sensation or pain during urination. They can also travel to the bladder and kidneys, where they often cause more serious infections. Though men get them, women are more susceptible. UTIs can be sexually transmitted.
E. Coli
The most common cause of a urinary tract infection is Escherichia coli (E. coli). This bacteria typically lives in the intestines but may gain access to the urinary tract by spreading from the anus to the genitalia, according to the Urology Channel. This is particularly the case for infants who wear diapers. Women are more likely to develop an E. coli infection in their urinary tract due to the proximity of the opening to the urinary tract to the anus. The female urethra is also shorter than that of the male, which makes it easier for the bacteria to gain access to the bladder.
Staphylococcus Saprophyticus
Staphylococcus saprophyticus can also cause a urinary tract infection. According to the University of Maryland Medical Center, this bacterial strain causes somewhere between 5 and 15 percent of all UTIs. Younger women are more likely to develop this kind of infection.
Sexually Transmitted Causes
Mycoplasma hominis and Chlamydia trachomatis, two strains of bacteria, can cause urinary tract infections. These bacteria are often transmitted during sexual intercourse.
Causes of Complicated Infections
The University of Maryland Medical Center notes that there are some organisms that can cause severe or complicated (a result of anatomical or physiological abnormalities) urinary tract infections. These include Citrobacter, Klebsiella and Proteus mirabilis. Candida (a type of yeast) can also infect the urinary tract. Finally, some bacteria that more typically infect other tissues, such as the Enterobacter group (digestive tract) or Pseudomonas aeruginosa (pneumonia) can also cause infections of the urinary tract.
