3. Insertion of study catheters: Subjects requiring fluoroquinolone antibiotics to clear their bladders will receive a study catheter 4-5 days after completing treatment. Subjects requiring any other class of antibiotics will receive a study catheter 2-3 days after completing antibiotic treatment. The study catheter will be inserted in by research personnel or by the unit nurse. Insertion will be performed using sterile technique. Urine will be collected through the newly inserted study catheters and cultured by study personnel.