Bacterial isolates from the urine of cattle affected by urothelial tumors of the urinary bladder.

Microbiological investigations were performed on urine samples from 108 cows affected by urothelial tumors of the urinary bladder. Bacteria, frequently of mixed population, were isolated from 100 animals. Gram-positive bacteria prevailed, with Staphylococcus spp. and Bacillus spp. being the most common. Escherichia coli and Acinetobacter spp. were the most frequently recovered Gram-negative bacteria. E5 oncoprotein was detected in 86 of the 108 urothelial tumors under study. In the majority of cases, bacterial agents and BPV-2 E5 were simultaneously detected. A marked down-regulation of Tamm-Horsfall protein was also observed in the examined cases. In addition, the p65 subunit of the nuclear factor-kappa B (NF-kappa B) transcription factor appeared to be overexpressed. In all cases, a mild to severe chronic inflammation was evident in the stroma of urinary bladder tumors.