Bacteria

If bacteria grow in the urine culture test and you have symptoms of an infection or bladder irritation, it means you have a UTI (= Urinary tract infection).

Urine contains fluids, salts and waste products but is sterile or free of bacteria, viruses and other disease-causing organisms. A UTI occurs when bacteria from another source, such as the nearby anus, gets into the urethra. The most common bacteria found to cause UTIs is Escherichia coli (E. coli). Other bacteria can cause UTI, but E. coli is the culprit about 90 percent of the time.

E. coli normally lives harmlessly in the human intestinal tract, but it can cause serious infections if it gets into the urinary tract. In women, the trip from the anus to the urethra is a short one. This is the reason why "wiping front to back" after using the toilet is helpful in preventing UTI.

This result is a positive urine culture test or abnormal test result.

The lab conducts an antibiotic sensitivity test on the bacteria in the cultured sample. Also called an antibiotic susceptibility test, this test identifies the type of bacteria causing the infection and which antibiotics the bacteria is sensitive to, meaning which antibiotics will kill the bacteria.

This information helps your healthcare provider select the most effective antibiotic medicine.

Certain antibiotics only work against certain bacteria. And some bacteria have antibiotic resistance. This means the antibiotic no longer can stop that type of bacteria from growing. Antibiotic-resistant infections are harder to treat.

Treatment for a UTI caused by E. coli:

An untreated UTI can move up to the kidneys and cause an even more serious infection, so prompt diagnosis and treatment is important. Sexually active women, pregnant women and older women all may be at increased risk for UTI.

The first line of treatment for any bacterial infection is antibiotics.

If your urinalysis comes back positive for germs, a doctor will likely prescribe one of several antibiotics that works to kill E. coli, since it’s the most common UTI culprit.

If a urine culture finds a different germ is behind your infection, you’ll get switched to an antibiotic that targets that germ.

You may also receive a prescription for a drug which helps reduce bladder pain.

If you tend to get recurrent UTIs (four or more per year), you may need to be on low-dose antibiotics daily for a few months.

Your doctor may also prescribe other medications for treatment that are not antibiotic based.