Solidago, orthosiphon, birch and cranberry extracts can decrease microbial colonization and biofilm development in indwelling urinary catheter: a microbiologic and ultrastructural pilot study

Plants extracts are used in urology to manage urinary tract infections. We aimed to evaluate the efficacy of a preparation with solidago, orthosiphon, birch and cranberry extracts (CISTIMEV PLUSA (R)) in reducing microbial colonization and biofilm development in patients with indwelling urinary catheters. All consecutive outpatients attending our department between January and June 2010 for the substitution of indwelling catheters were considered for this single-blinded, randomized and controlled pilot study to test superiority of the preventative management (CISTIMEV PLUSA (R), 1 tablet daily for 30 days) in respect to no treatment. A sample size of 10-40 participants per group was considered adequate. All patients underwent urine culture the same day of the catheter substitution and were then randomized into test group (n = 48) and control group (n = 35). Ultrastructural analysis was also performed. After 30 days, the catheter was replaced and the analysis repeated. The primary outcome was the rate of positive urinary culture at the end of the entire study period. Ten patients abandoned the study. At 30 days, according to per-protocol analysis, the groups statistically differed regarding the rate of positive urine cultures: test group 10/43 and control group 16/30 (p = 0.013) (-30.1 % [95 % CI -51.94 to -8.21]). The most common isolated bacteria were Escherichia coli and Enterococcus faecalis. The use of solidago, orthosiphon, birch and cranberry extracts resulted in a significant reduction of microbial colonization in patients with indwelling urinary catheters. Larger clinical trials are needed to demonstrate that the effects here reported are sufficient to reduce symptomatic catheter-associated urinary tract infections.