Summary

• Urine tests can help find out if you have a urinary tract infection (UTI).
• Urinalysis and urine culture are the tests you are most likely to have. 
• Your GP or health clinic may start with a dipstick urinalysis that looks for signs that an infection is present. 
• If there are signs of infection, your urine sample will be sent to the lab for a urine culture, also known as urine MCS. 
• Urine culture looks for the bacteria or yeast that cause infection. Very rarely, a UTI can be caused by yeast infection.
• Once the type of bacteria is known, the lab will do a sensitivity test to see which antibiotics or antifungals will be effective. 

What are UTIs?

Urinary tract infections (UTI) affect the bladder and/or the kidneys. Urine is made by your kidneys and collects in your bladder until you urinate. Normally, urine in the bladder contains no bacteria - it is sterile – but if bacteria or yeast get into the urinary tract, they can cause an infection.

Bladder infections are common, and they mostly happen to women. They are due to bacteria getting into the urethra – the tube that runs from the bladder to the vagina or penis – and travelling up into the bladder. Bladder infections are known as uncomplicated UTIs or cystitis. A complicated UTI is when the infection travels beyond the bladder up to the kidneys. This is a more serious condition.

Why get tested?

In many situations, a urine culture is not needed before you start treatment. If you are a woman and have symptoms that are typical of bladder infection, you can seek help from your GP or pharmacist who may prescribe antibiotics without ordering tests. Antibiotic treatment can usually be started based on your symptoms alone or on the results of a dipstick urinalysis test. This will usually be an antibiotic that is known to work in most cases of UTI. By far the most common type of bacteria found in a UTI is E. coli and it can be treated successfully with several different antibiotics.

Who is more likely to need a urine culture?

• Pregnancy
  All women who are pregnant are advised to have a test for bacteria in their urine in the first trimester – first three months of pregnancy– even if they don’t have symptoms. This is because there is a risk of developing kidney infection in later pregnancy.
• Men
  UTIs in men are uncommon although more likely to occur as they get older. If someone has diabetes, has low immunity because of illness or treatment, or uses a catheter, they are at greater risk of getting an infection. Younger men rarely get a UTI and for those who do, sexually transmitted infections are usually the cause.
• Aged-care facility residents 
  UTI is a common infection in older people, especially those in aged care. Older people generally have lower immunity, and they often have health conditions such as diabetes, stroke, dementia and bowel or bladder incontinence that make them more likely to get infections. They are also more likely to have in-place catheters. UTIs can be more difficult to identify in older people than younger people. They can have symptoms that are not typical and experience sudden, severe illness.
• Persistent symptoms
  You may need a urine culture test if you are not responding to treatment and your symptoms persist or if your infection keeps coming back. If you have recently been in hospital or if you have been travelling to parts of the world where there are known to be multidrug-resistant bacteria you also may need a urine culture.

Yeast infections

Yeast infections as the cause of UTIs are rare, and generally only occur when someone has a urinary catheter or other urinary instrumentation in place – usually in hospital. When yeast is found in a urine sample, it may be because the sample has been contaminated by yeast infection (thrush) of the vaginal area.

How is the sample tested?

When the sample arrives in the lab it is investigated under a microscope or placed in a cell counting instrument where the cells are counted. If there are large numbers of white blood cells – called ‘pus cells’ – it is very likely you have a UTI.

A small amount of urine is then cultured. To do a urine culture, a sample of your urine will be put into a special substance called a culture medium that helps the bacteria or yeasts to grow. Plates of culture medium are placed in an incubator for 24 hours. The culture is usually termed ‘negative’ if no growth is found on the plates after 24 hours. If there are bacteria or yeasts growing, they are counted.

Next, susceptibility tests are carried out to decide which antimicrobials are likely to be effective in treating the infection.

Having the test

Sample

You need to collect a mid-stream urine sample. This means you don’t collect the first or last part of the urine that comes out. This is important because it is very easy for your urine sample to be contaminated if it touches the skin around your urethra. By only collecting the mid-stream of urin, bacteria on your skin can be washed away in the first part of your urine stream. Everyone has bacteria on their skin including around the opening of the urethra that opens into the vagina or penis. 

Your doctor, collection centre or pharmacist will give you a sterile pot with a lid and a bag in which to put it. Here are a few steps:

• Wash your hands. 
• Remove the lid from the pot. 
• Don’t touch the inner surface.
• Clean or wipe your genital area. 
  • Male - retract the foreskin (if uncircumcised) while peeing. 
  • Female - sit on the toilet seat and keep your legs apart.
• Pass a small amount of urine into the toilet – to a count of three. 
• Then fill the pot to about half full. 
• Pass the rest into the toilet bowl. 
• Replace the lid and tighten.
• Wash your hands.
• Label the pot as per instructions. 
• Place the pot in the bag. 

If you can’t hand your sample in within an hour you need to put it in the fridge. Make sure you don’t freeze it.

Any preparation?

None.

Your results

Reading your test report

Your results will generally be presented along with those of your other tests on the same form.  You will see separate columns or lines for each of these tests.  

The number of organisms in a urine sample is given as colony forming units per litre (CFU/L). Your result will be negative or positive.

Questions to ask your doctor

The choice of tests your doctor makes will be based on your medical history and symptoms. It is important that you tell them everything you think might help.

You play a central role in making sure your test results are accurate. Do everything you can to make sure the information you provide is correct and follow instructions closely.

Talk to your doctor about any medications you are taking. Find out if you need to fast or stop any particular foods, medications or supplements. These may affect your results. Ask:

• Why does this test need to be done?
• Do I need to prepare (such as fast or avoid medications) for the sample collection?
• Will an abnormal result mean I need further tests?
• How could it change the course of my care?
• What will happen next, after the test?

More information

Pathology and diagnostic imaging reports can be added to your My Health Record.

You and your healthcare provider can now access your results whenever and wherever needed. Get further trustworthy health information and advice from healthdirect.