What is prostate bacterial culture?

Prostate bacterial culture is a method of laboratory testing by collecting prostatic fluid samples and is mainly used to diagnose bacterial prostatitis. The test mainly includes sample collection, culture medium inoculation, bacterial isolation and identification, drug susceptibility testing and other steps. Test results can help identify pathogenic bacteria and guide antibiotic selection.

1. Sample collection

The doctor obtains prostatic fluid through rectal massage and uses a sterile container to collect 3-5 drops of secretion. Abstinence is required for 3 days before collection, and sampling immediately after urination can reduce urinary tract bacterial contamination. Some patients may need to cooperate with urinary flow rate examination to confirm the validity of the sampling.

2. Medium inoculation

In the laboratory, the specimens are inoculated into selective media such as blood agar plates and chocolate plates and placed in a 35-37°C carbon dioxide incubator. Synchronous Gram staining microscopy is required to initially determine the bacterial morphology, and colony growth is observed 24-48 hours after inoculation.

3. Isolation and identification of bacteria

After purifying and culturing the growing single colony, biochemical reactions, mass spectrometry and other methods are used to identify the bacterial species. Common pathogenic bacteria include Escherichia coli, Staphylococcus aureus, Enterococcus, etc. In mixed infections, colonizing bacteria and pathogenic bacteria need to be distinguished.

4. Drug sensitivity test

The sensitivity of bacteria to various antibiotics is tested using disk diffusion or broth microdilution methods. Focus on testing drugs with strong prostate penetration, such as levofloxacin and ceftriaxone, and the results are reported in three levels: sensitive, intermediate, and resistant.

5. Clinical significance

The gold standard for diagnosing bacterial prostatitis, positive culture can identify the pathogen in more than 95% of acute cases. The positive rate of chronic prostatitis is about 30%. If repeated cultures are negative, non-bacterial causes should be considered. The results need to be judged comprehensively based on symptoms and signs.

Sexual intercourse and the use of antibiotics should be avoided for 3 days before the examination, and you should drink plenty of water after collection to prevent urinary tract infection. If fever or persistent pain occurs, timely follow-up is required. Pay attention to keeping the perineum clean and dry every day, and avoid long-term riding or sitting that may compress the prostate. The diet should be light and limit the intake of alcohol and spicy food.