Why would a Urologist start a patient on a Quinolone without having sensitivities to a urine culture?

Im a lab technician and all I can say is that it is the doctors responsibility to order a sensitivity..none of the labs I have worked in automatically do them..as for quinolone..its a broadspectrom antibiotic so unless this is an organism that this person has been fighting for a lond time and used several antibiotics on..its a good choice for a start..usually sensitivities are not needed if it is a "new" infection...they usually start off with a broad spectrom like quinolone and if it doesnt work or until the sensitivities come back its a good choice..quinolone is commony used with urinary tract type of stuff