Bladder infection (cystitis) can occur as a complication after endoscopic cystoscopy. Microbiological analyses are requested to identify the provoker and to test its sensitivity to various antibiotics (antibiogram). You didn’t tell me why you have done cystoscopy, which bacterium was isolated from the urine, which antibiotic you used and did you made control microbiological examination after the antibiotic treatment was finished. If you don’t have some other urinary tract disorders prevention of another urinary tract infection (UTI) is not necessary. But if you have some urinary tract disorder that makes you susceptible to UTI you can use some prevention.