Normal range of bacteria in urine test

Bacterial infection is a relatively common symptom. For the human urinary tract system, if bacterial infection occurs, it often causes a variety of symptoms, such as frequent urination, urgency and pain when urinating, etc. At this time, you should go to the hospital for examination in time and check for bacteria through urine tests. At this time, we can use smear bacterial examination and bacterial culture to understand the specific bacteria. Let’s take a look at this aspect.

Normal range of urine bacteria

Smear bacterial examination: Clean midstream urine sediment smear, Gram stain with oil immersion lens or without staining with high-power microscope, count the number of bacteria in 10 fields of view and take the average value. If one or more bacteria are seen in each field of view, it indicates urinary tract infection. This method has simple equipment and is easy to operate, with a detection rate of 80% to 90%. It can preliminarily determine whether it is a bacillus or coccus, and whether it is a Gram-negative or Gram-positive bacteria, and has important reference value for timely selection of effective antibiotics.

Bacterial culture: Clean midstream urine, catheterization and bladder puncture urine can be used for bacterial culture, among which bladder puncture urine culture results are the most reliable. If the quantitative culture result of midstream urine bacteria is ≥10 to the power of 5/ml, it is called true bacteriuria, which can confirm urinary tract infection; if the quantitative culture result of urine bacteria is 10 to the power of 4 to 5/ml, it is suspected positive and needs to be rechecked; if it is <10 to the power of 4/ml, it may be contamination. If bacteria grow during the qualitative culture of urine from suprapubic bladder puncture, it is considered true bacteriuria.

Precautions

Urinalysis is not only a commonly used examination method for urinary system diseases, but also an auxiliary analysis tool for certain other systemic diseases. Many patients often go to the hospital for routine urine tests when they feel unwell to check for hematuria, proteinuria, etc. to prevent kidney disease. However, some patients cannot understand the results after the examination, so we simply analyze the results of the routine urine examination.

Patients with urinary system diseases are best examined using morning urine. Urine specimens should be collected as midstream urine: that is, a portion of urine should be discharged first to flush out the bacteria remaining in the urethral opening and anterior urethra, and then the midstream urine should be collected for testing.

The following situations should be avoided as much as possible: adult women should avoid the menstrual period to avoid the mixing of vaginal secretions; male patients should avoid the mixing of prostatic fluid, etc. Normal urine is clear and transparent, with a color ranging from light yellow to dark yellow. The color of urine is affected by urochrome, food, and medications. The daily excretion of urochrome is roughly constant, so the depth of urine color varies with the amount of urine. If the urine is excreted for too long, it will become slightly turbid. This is because the acidity and alkalinity of the urine change, and the mucus protein, nucleoprotein, etc. in the urine gradually precipitate.