Microbial flora in ileal and colonic neobladders

To describe bacterial colonization in patients with ileal and colonic neobladders.

Twenty-three patients with right colon neobladders, 30 with ileal neobladders, 11 who had undergone radical prostatectomy, and 6 healthy controls were included. Culture of clean-catch, midstream urine specimens was done weekly for 3 weeks, and this was repeated after 6 months. Residual urine was measured, and the patients were interviewed about leakage. All patients and controls were antibiotic free during the study except for 13 of the ileal neobladder patients, who were treated with trimethoprim 100mg daily.

Urine cultures from controls and prostatectomy patients were negative for bacteria, whereas 67% of the specimens from patients with neobladders, not on antibiotic therapy, were culture positive, and half of these contained uropathogenic species, such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterococcus faecalis. Bacterial colonization (including uropathogenic strains) was strongly correlated with residual urine (p<0.005), but not with leakage. Anaerobic strains were found more frequently (p=0.04) in urine from ileal neobladders than in urine from colonic neobladders. The 13 patients with ileal neobladders and on prophylactic antibiotic therapy carried bacteriuria in 80% of the samples, the majority being anaerobic strains. Uropathogenic strains, mainly Enterecoccus faecalis was revealed in 30% of the samples.

The lower urinary tract of patients with ileal or colonic neobladders is heavily colonized with potentially uropathogenic and anaerobic bacteria. Complete bladder emptying reduces the bacterial burden. Anaerobic colonization is increased in neobladders reconstructed from ileum. Prophylactic antibiotic therapy does not seem to reduce the bacterial burden, but interferes with the bacterial composition.