@dribbles
Which Mayo are you going to?
Quite frankly never heard (but does not mean it is not done) a P.A. doing a biopsy? It is surgery procedure. Were you seeing a urologist? Most of the time urologist does the biopsy.

If you have biopsies transperineally there is a very low risk of infection versus transrectal at 2% risk (per Mayo Jacksonville urologist not my quote). Transrectal goes through the rectum.

Most every surgeon will tell you that the highest risk of surgeries is infection. Most hospitals will tell you they try to get you out of a hospital ASAP because of the increased infection rates while you are in there.

So if me, and I know I am not, would want the antibiotic.
Good luck on your biopsy!