Dr. Saoji Orthopaedic Clinic And Medilab Pathology Laboratory
Sky Orthopaedics,1st Floor, Nikalas Tower, Central Bazar Road,Nagpur
4.3 / 5
Home sample collection available
MON-SAT 8:00 AM to 8:00 PM
Know About Culture & Sensitivity, Aerobic bacteria Urine
Urine is the fluid that contains water and wastes and that is produced by the kidneys. It travels from the kidneys, through tubes called ureters to the bladder, and then is eliminated from the body through the urethra. The urine culture is a test that detects and identifies bacteria and yeast in the urine, which may be causing a urinary tract infection (UTI).
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 as small circular colonies. The size, shape, and color of these colonies help to identify which bacteria are present, and the number of colonies indicates the quantity of bacteria originally present in the urine sample. A laboratorian observes the colonies on the agar plate, counting the total number and determining how many types have grown. Ideally, if a good clean catch sample was collected for the test (see below), then the only bacteria present should be due to an infection. Typically, this will be a single type of bacteria that will be present in relatively large numbers. Sometimes, more than one type of bacteria will be present. This may be due to an infection that involves more than one pathogen; however, it is more likely to be due to contamination from the skin picked up during the urine collection.
The laboratorian will take a colony from each type and perform a gram stain. The laboratorian examines the microorganisms under the microscope. Different types of bacteria will exhibit characteristic colors and shapes. For instance, the bacterium Escherichia coli, which causes the majority of urinary tract infections, will appear as pink (gram-negative) rods under the microscope. Lactobacillus, which is a common vaginal contaminant in women's urine samples, will appear as thin purple (gram-positive) rods. Some of the bacteria, such as Lactobacillus, are easy for an experienced laboratorian to identify, are nonpathogenic, and do not require any further investigation. Others, such as gram-negative rods, represent groups of similar bacteria and will require additional testing to determine exactly which type of bacteria is present.
If there is no or little growth on the agar after 24 to 48 hours of incubation, the urine culture is considered negative for pathogens and the culture is complete. If there are one or more pathogens present, further testing is performed. Testing is done to identify which bacteria are present and susceptibility testing is done to identify antibiotics that are likely to cure the infection.
Urine Culture and Sensitivity; Urine C and S; Culture, Urine.
Urinary Tract Infection
To diagnose a urinary tract infection (UTI). When you experience symptoms of a UTI, such as frequent and painful urination, and/or when a urinalysis indicates you may have a UTI.
A urine culture may be ordered when a person has symptoms that indicate the possibility of a urinary tract infection (UTI), such as:
A strong, persistent desire to urinate
A burning sensation during urination
A cloudy, strong-smelling urine
Lower back pain
People with UTIs may also have pressure in the lower abdomen and small amounts of blood in the urine. If the UTI is more severe and/or has spread into the kidneys, it may cause flank pain, high fever, shaking, chills, nausea or vomiting.
Sometimes, antibiotics may be prescribed without requiring a urine culture for young women with signs and symptoms of a UTI and who have an uncomplicated lower urinary tract infection. If there is suspicion of a complicated infection or symptoms do not respond to initial therapy, then a culture of the urine is recommended.
Pregnant women without any symptoms are recommended to be screened during the first trimester or first prenatal visit for bacteria in their urine, which could affect the health of the developing baby.
A urine culture may be ordered with a urinalysis or as follow up to abnormal results on a urinalysis.