This study will be a multi-institutional randomized clinical trial of a short course of pre-operative antibiotic prophylaxis in addition to perioperative antibiotics. Once patients have been identified and enrolled into the study, they will be grouped based on the sensitivity profiles of their positive urine culture or the presence of indwelling kidney drain tube (nephrostomy tube, nephroureteral stent, ureteral stent). Each of these groups will be individually randomized as follows: