Inflammation. Coloured scanning electron micrograph (SEM) of leucocytes (white blood cells) in urine from a patient with acute bacterial prostatitis. Acute bacterial prostatitis (ABP) is thought to result from an ascending urethral infection or reflux of infected urine into the prostatic ducts. Bacteria that cause prostatitis are similar in type and incidence to those commonly causing urinary tract infections. Although common strains of Escherichia coli predominate, other species may be present including, Klebsiella, Proteus, Enterobacter, Pseudomonas, and Serratia. ABP is usually diagnosed by the increased presence of bacteria and white blood cells in the urine. Antibiotics are usually use to treat acute bacterial prostatitis. Magnification: x2500 when printed 10 centimetres wide.