A urinary tract infection (UTI) is the presence of bacteria in the urinary tract, which is made up of the urethra, bladder, ureters and kidneys. The National Kidney and Urological Diseases Information Clearinghouse reports that UTIs are the second most common type of infection in humans. An infection involving the urethra is known as urethritis. An infection of the bladder is known as cystitis. An infection that reaches the kidneys is the most serious and is called pyelonephritis. There are several types of bacteria that typically cause UTI.
Escherichia coli
Escherichia coli, also known as E. coli, is a bacteria that is a normal inhabitant of the digestive tract. Although some strains of E. coli can cause serious illness, especially when it enters the bloodstream, some E. coli is beneficial to the body. E. coli that lives in the intestines helps to break down food aiding in digestion. Because E. coli live in the colon, the portion of the large intestine just before the rectum, stools often contain some of the bacteria.
The bacteria can travel from the rectum to the opening of the urethra. Women are especially susceptible because their rectum and urethra are so close together. This is why women suffer from UTIs more than men, according to the Mayo Clinic. Once the bacteria gain entry into the urethra they can travel up the urethra to the bladder where they multiply, causing an infection.
Chlamydia
Chlamydia is a sexually transmitted disease caused by the bacteria Chlamydia trachomatis. This disease affects more than 2 million people in the United States, according to Chlamydia Community. Although it is a sexually transmitted disease and typically infects the reproductive organs of both men and women, it can also cause UTIs.
In women, the close proximity of the vaginal opening and the opening of the urethra makes cross-contamination easy. During sexual intercourse the urethral opening may become irritated which allows the bacteria to gain entry and easily move through the urethra. Chlamydia UTI are normally limited to the urethra but both the female and her male partner must be treated to ensure the bacteria is eliminated.
Mycoplasma
Mycoplasma hominis is a bacteria that is one of the natural organisms found in the female genital tract. This bacteria is an opportunistic bacteria, meaning that if there are changes to the natural vaginal environment, triggered by hormones or medications, they can multiply out of control. During sexual intercourse the bacteria can be transferred to the urethra. Although these bacteria rarely cause bladder infections, it is a common cause of urethritis, according to Bladder Disorders.
