11. Duration of participation: If a subject remains colonized with E. coli 83972 on day 28 after removal of the study catheter, and if the subject declines antibiotics to eradicate the study organism, we will continue to collect monthly urine specimens until the organism is lost from the bladder or until completion of 12 months, whichever comes first. Thus, an individual subject's participation in the study will be limited to 12 months or less.