Final answer:
Infection in a urine sample is typically diagnosed through a urinalysis with urine test strips, followed by microscopic examination and urine culture to detect and identify any bacteria present. A clean catch of urine is important for accurate results to avoid contamination.
Step-by-step explanation:
To determine an infection in a urine sample, a urinalysis is commonly performed. The initial screening often includes evaluating the urine's appearance and using urine test strips. When abnormal results are detected, such as the presence of nitrites, leukocyte esterase, protein, or blood, this may indicate an infection. Infections are commonly caused by bacteria, including Escherichia coli and Klebsiella pneumoniae, which produce nitrate reductase converting nitrate to nitrite, detectable on the test strips.
If a urinary tract infection (UTI) is suspected, further testing includes a microscopic examination of the urine and a urine culture. For accurate results, it is advisable to collect a clean catch of urine to minimize contamination from the normal microbiota. The microscopic study might reveal the presence of bacteria, proteins, red and white blood cells, or cellular casts. A urine culture helps to determine which type of bacteria is present, guiding the selection of appropriate antibiotics for treatment.