7. Microbiologic studies: Semi-quantitative cultures will be performed on each urine sample to determine whether E. coli 83972 is present and the relative concentration of each other species in the urine. The presence in the urine of bacteria other than E. coli will be examined using standard bacteriological methods only. E. coli strains will be assessed using standard microbiological techniques as well as molecular techniques in the research laboratory. Urine will be spread on MacConkey lactose agar plates and incubated to allow bacterial growth. Representative E. coli colonies will be subjected to restriction fragment length polymorphism (RFLP) analysis using pulse field gel electrophoresis (PFGE) to definitively identify E. coli 83972. The removed urinary catheters will be sonicated to extract surface-associated organisms. An aliquot of each sonicate will be plated for identification of organisms.