Bacterial colonization of bladder urothelial cells in women with refractory Detrusor Overactivity: the effects of antibiotic therapy.

Bacterial infection may have a pathophysiological role in refractory Detrusor Overactivity (DO). The aim of this study was to observe any impact of antibiotic therapy upon bacterial colonization of urothelial cells, and to determine whether a relationship existed between colonization and symptom severity. Mid-stream urine samples were collected as part of a clinical trial of antibiotics in women with refractory DO. Wright stained urothelial cells were categorized according to the degree of bacterial colonization as; 'clear' (free of bacteria), or as associated with bacteria that were 'adjacent' to the cell or 'intracellular' at low or high density. The average percentages were compared with routine microbiology cultures, over the 26 week trial, and with patient clinical outcome measures of DO severity. In patients receiving placebo, 'high-density intracellular bacteria' significantly increased during urinary tract infection (P = 0.0008). In antibiotic patients, 'clear' cells were more prevalent. Amoxicillin & Clavulanic Acid significantly decreased bacterial colonization within urothelial cells, suggesting that these antibiotics possess the greatest intracellular efficacy. 'High-density intracellular bacteria' positively correlated with symptom severity, measured by leakage on pad test (P = 0.014), leaks per day (P = 0.004), and voids per day (P = 0.005). Thus, by decreasing high density intracellular bacteria, antibiotic treatment may improve the refractory DO condition.