When patients are ambulatory and competent, this is a self-obtained specimen in a private bathroom. If the urine is not collected in a sterile manner the urine sample may be ‘contaminated’ by
bacteria that originate from the skin or genital area
, and not from the urinary tract.
How do you know if a urine sample is contaminated?
A contaminated urine specimen can give a large amount of false data on a dipstick test.
Greater than five epithelial cells on microscopic evaluation
is likely a sign of contamination.
What can cause contaminated urine?
The two most common sources of contamination in urine from young children are
faeces and skin
. E. coli and enterococci are common faecal organisms and as such would be represented highly in contaminated urines; however, E. coli is also the most common cause of UTI.
What is contamination in the urine?
Contamination: If
a culture shows growth of several different types of bacteria
, then it is likely that the growth is due to contamination. This is especially true in voided urine samples if the organisms present include Lactobacillus and/or other common nonpathogenic vaginal bacteria in women.
What are contaminants in urine culture?
Contamination is likely if only small numbers of bacteria or several bacterial species grow in urinary cultures.
Lactobacilli, Corynebacteria species, Gardnerella, alpha-haemolytic streptococci, and aerobes
are considered urethral and vaginal contaminants.
Can a urine test detect STDS?
Sexually Transmitted Infections (STIs) A urinalysis can give clues to the presence of sexually transmitted infections. A positive dipstick for leukocyte esterase or increased numbers of white blood cells in the microscopic exam is suggestive of
chlamydia
or gonoccocal infection.
How long can a urine sample last?
Storing a urine sample
Do not keep it for longer than
24 hours
. The bacteria in the urine sample can multiply if it is not kept in a fridge. If this happens, it could affect the test results.
When is the best time to take a urine sample?
Your doctor will provide a container for the urine sample. You may be asked to collect the sample
first thing in the morning
because at that time your urine is more concentrated, and abnormal results may be more obvious.
What color is dirty urine?
Urine gets its color, which is typically
yellow
, from a pigment called urochrome, or urobilin. Lighter colored urine is more diluted, whereas darker urine contains less fluid. Very dark urine could be a sign that you’re dehydrated. If your urine doesn’t fit within this color scheme, don’t panic.
How do you clean a urine sample?
- Sit on the toilet with your legs spread apart. Use two fingers to spread open your labia.
- Use the first wipe to clean the inner folds of the labia. Wipe from the front to the back.
- Use a second wipe to clean over the opening where urine comes out (urethra), just above the opening of the vagina.
What infections can be found in urine?
- urethritis – infection of the urethra.
- cystitis – infection of the bladder.
- pyelonephritis – infection of the kidneys.
- vaginitis – infection of the vagina.
What are the symptoms of bacteria in urine?
- A strong, persistent urge to urinate.
- A burning sensation when urinating.
- Passing frequent, small amounts of urine.
- Urine that appears cloudy.
- Urine that appears red, bright pink or cola-colored — a sign of blood in the urine.
Why do I keep getting bacteria in my urine?
When waste products and excess water is removed from your blood by the kidneys, urine is created. Normally, urine moves through your urinary system without any contamination. However, bacteria can get into the urinary system from outside of the body,
causing problems like infection and inflammation
.
How do you perform a urine culture?
For a urine culture, a small sample of urine is placed on one or more agar plates (a thin layer of a nutrient media) and
incubated at body temperature
. Any bacteria or yeast that are present in the urine sample grow over the next 24 to 48 hours.
Is mixed growth in urine an infection?
mixed growth may
indicate perineal contamination
; however a small proportion of UTIs may be due to genuine mixed infection. Consider a re-test if symptomatic.
Can urine culture detect kidney infection?
To confirm that you have a kidney infection, you’ll likely be asked to provide a
urine sample
to test for bacteria, blood or pus in your urine. Your doctor might also take a blood sample for a culture — a lab test that checks for bacteria or other organisms in your blood.
