Search results
Results From The WOW.Com Content Network
Urine culture is quantitative and very reliable, but can take at least one day to obtain a result and it is expensive. [8] [14] Miniaturization of bacterial culture within dipstick format, Digital Dipstick, [15] allows bacterial detection, identification and quantification for bacteriuria within 10–12 hours at the point-of-care.
Normal urine pH is slightly acidic, with usual values of 6.0 to 7.5, but the normal range is 4.5 to 8.0. A urine pH of 8.5 or 9.0 is indicative of a urea-splitting organism, such as Proteus, Klebsiella, or Ureaplasma urealyticum; therefore, an asymptomatic patient with a high pH means UTI regardless of the other urine test results.
In some cases, urine samples or positive blood culture samples are applied directly to the test medium, bypassing the preliminary step of isolating the organism. [15] If the antibiotic inhibits microbial growth, a clear ring, or zone of inhibition, is seen around the disc.
It normally ranges from 1.003 to 1.035; lower values indicate that the urine is dilute, while higher values mean that it is concentrated. A urine specific gravity that consistently remains around 1.010 (isosthenuria) can indicate kidney damage, as it suggests that the kidneys have lost the ability to control urine concentration. [39]
Others additionally require discoloration, clouding or change in the smell of urine for a pyuria to be present. Without these additional features, there is said to be leukocyturia. Sterile pyuria [1] is urine which contains white blood cells while appearing sterile by standard culturing techniques. It is often caused by sexually transmitted ...
Analysis of the urine may show signs of urinary tract infection. Specifically, the presence of nitrite and white blood cells on a urine test strip in patients with typical symptoms are sufficient for the diagnosis of pyelonephritis, and are an indication for empirical treatment. Blood tests such as a complete blood count may show neutrophilia.
Urinalysis is the most useful test to start the work up in a patient of dysuria. Urinalysis positive for nitrite carries a high predictive value of a positive urine culture. Also, urine dipstick showing leukocytes as equal predictive value as the presence of nitrites. When both are present, the predictive value goes even higher.
Colonial morphology serves as the first step in the identification of microbial species from clinical samples. [10] Based on the visual appearance of the colonies, microbiologists can narrow down the list of possible organisms, allowing them to select appropriate tests to provide a definitive diagnosis.