Prostate biopsy is usually conducted transrectal, ultrasonography guided. Since the area is not sterile, infection can be induced during the procedure.

Prophylaxis antibiotic against gram-negative bacteria decreased significantly the amount of infections. Quinolones are considered preferred treatment but there is already an increase in resistance rates. TMP-SMX can not be used empirically due to a high percent of resistant uropathogens. One of the options is aminoglycosides, especially gentamicin. Advantages: very low resistance rate in the community, high concentration is urinary tract, slow clearance, no resistance developed under treatment, chip and with very few side effects.

Prostate biopsy is usually conducted as an ambulatory transrectal needle aspiration, ultrasonography guided. The area is not sterile, with high concentration of gram-negative and anaerobic pathogens, infection can be induced during the procedure to the urinary tract, and even cause bacteremia.

Prior studies concluded that prophylaxis antibiotic against gram-negative bacteria decreased significantly the amount of infections and hence it is accepted to give prophylaxis antibiotics which will cover especially gram-negative bacteria. Other studies show decrease in infections percent in patients that received prophylaxis opposed to those who did not, from 5-30% to less than 1%. Yet, there was no significant difference between those who received one dose and those who were treated for 3-5 days. Quinolones are considered preferred treatment since they can be given orally, but there is already an increase in resistance rates. TMP-SMX can not be used empirically due to a high percent of resistant uropathogens. One of the options is aminoglycosides, especially gentamicin. Advantages: very low resistance rate in the community, high concentration is urinary tract, slow clearance, no resistance developed under treatment, chip and with very few side effects.

Inclusion Criteria:

• Patients going under transrectal biopsy of prostate with sterile urine culture.

Exclusion Criteria:

• Urine culture not sterile