Chronic bacterial prostatitis is a non-acute infection of the prostate caused by one or more pathogenic bacteria. Like acute bacterial prostatitis, the pathogenic bacteria are gram-negative aerobic bacteria, such as Escherichia coli and Pseudomonas aeruginosa. Some clinical experts believe that gram-positive bacteria (such as staphylococcus, streptococcus, diphtheria-like bacteria) can also cause prostatitis, but unlike the prostate infection caused by gram-negative bacteria, the prostate infection caused by gram-positive bacteria rarely persists or causes repeated attacks of infection, with the exception of prostatitis caused by enterococcus. However, many authors are skeptical of the chronic prostatitis caused by gram-positive bacteria. At present, there is evidence that chlamydia and mycoplasma can also cause prostate infection, but it is rare.
The infection routes of acute and chronic bacterial prostatitis may be the same. Sometimes chronic cleft prostatitis obviously evolves from the untreated acute prostatitis, but there are also some patients without acute prostatitis.
The histological examination of chronic prostatitis is non-specific. Compared with acute prostatitis, the inflammatory reaction is lighter and more limited. Plasma cells, macrophages and lymphocytes can be seen in or around the acini or in the matrix. In 1979, Kohnen and Drach observed that 98% of the prostate had similar histological features from 162 male patients who underwent prostatectomy due to enlarged prostate. In this group of patients, there is little clinical or bacteriological evidence of prostate infection. Therefore, histological methods can not determine the exact diagnosis of chronic cellular prostatitis.