Urine Culture Overview
A urine culture is a test that can detect bacteria in your urine. This
test can find and identify the germs that cause a urinary tract infection (UTI). Bacteria, which typically cause UTIs,
can enter the urinary tract through the urethra. In the sterile environment of
your urinary tract, these bacteria can grow rapidly and develop into an
Who Is the Treatment For?
Urine cultures can locate and identify the microorganisms, typically bacteria,
which cause a UTI. UTIs are more common in females than males. This is because
a woman’s urethra is shorter and much closer to the anus. This makes it much
easier for bacteria from the intestines to find their way into the urinal
tract. Bacteria ascend the urethra into the bladder, kidney, and ureters, where
they can develop into an infection.
Symptoms of a UTI
The most common symptoms of a UTI are:
- pain and discomfort, typically in the lower back
and abdominal area
- pain when urinating
- feeling an urge to urinate frequently
How Is the Test Administered?
The urine for a urine culture can be collected in several different
ways. The most common method for collecting urine is the midstream clean-catch method. For this, you collect your urine in a
cup as you urinate. Before you begin this process, a healthcare provider will
ask you to wash your hands and then wash your genitalia several times with a
cleanser. Once this step has been completed, you will begin urinating into a sterile
cup provided by your doctor. The cup is then given to your healthcare provider,
who sends it to a lab for analysis.
A urine sample can also be collected with a urinary collection bag. This method is used most commonly with
children and infants. For this procedure, a plastic bag is attached with
adhesive to a girl’s labia or a boy’s penis. When the child begins urinating,
the bag catches the urine, which can then be sent to a lab for analysis.
In some cases, a healthcare provider needs to collect a urine sample
with a catheter. To do this, they
insert a thin rubber tube through the urethra and into the bladder. Once the
catheter is in place, the healthcare provider is able to collect a sample. If
you already have a urinary catheter in place, a healthcare provider can collect
a sample by clamping the drainage end of your catheter before it reaches the
drainage bag. Once urine passes into the clamped tube, your healthcare provider
uses a syringe to remove a urine sample. Urine samples cannot be taken directly
from a catheter collection bag because urine that has been out of the body too
long may begin to grow bacteria and will not be a good sample.
In rare cases, your doctor may need to remove a urine sample from your
bladder with a needle. This procedure, called a suprapubic aspiration, is used if previous attempts at collecting
an uncontaminated sample have been unsuccessful.
What Are the Risks of the Test?
Collecting a urine sample is not painful, unless you are experiencing
pain while urinating because of an existing UTI. There are no risks associated
with preparing for or performing a urine collection.
If your doctor requests a urine sample obtained with a catheter, you
may feel some pressure and discomfort as the thin tube is inserted through your
urethra. These tubes are lubricated to reduce pain and make the procedure much
easier. Rarely, a catheter can create a hole in your urethra or bladder. A
suprapubic aspiration can be painful, but your doctor will discuss with you
options of reducing pain while performing the procedure.
Before you begin your test, tell your doctor if you are taking or have
recently taken any medications or over-the-counter vitamins, medicines, and
supplements. These may interfere with the lab’s results. You do not need to
prepare for a urine culture except for washing your hands and your genitalia before
the clean catch collection. If you know you will need to conduct a urine
collection during an appointment with your doctor, avoid urinating until you’re
able to collect a sample. If you have any questions or concerns about the test,
the risks, or the results, speak with your healthcare provider.
What Are the Desired Results?
For a urine culture, the urine is given several days to begin growing
bacteria. The sample is then examined under a microscope. If your urine shows
signs of bacteria or other organisms, you will receive a positive result. If
few bacteria or organisms appear, you will receive a negative test result. The
person conducting the urine culture will also be able to determine which
organisms are causing the infection either by sight or through an additional
Results of a urine culture are typically ready in two to three days. If
your results come back positive, your doctor may prescribe you an antibiotic to
help eliminate the harmful bacteria.