In defense of routine antimicrobial susceptibility testing of operative site flora in patients with peritonitis.

The species and number of bacteria present at a surgical site correlate with postoperative wound infection. When organisms cultured from intraabdominal infections are resistant to the presumptive antimicrobial therapy, the incidence of postoperative wound and intraabdominal infections is significantly increased. Knowledge of operative site culture data allows identification of resistant organisms, leads to an early change in therapy, and guides selection of antimicrobials for treatment of postoperative complications. Anaerobic susceptibility data vary geographically, even differing within hospitals in the same city. Surveillance of resistance patterns of bacteria causing intraabdominal infections facilitates accurate initial therapy. Failure of treatment in the absence of bacteriologic results confirming appropriate antimicrobial therapy may be difficult to rationalize on a medicolegal basis. In summary, it is advisable for surgeons to perform cultures and susceptibility tests for both aerobic and anaerobic organisms present in intraabdominal infections.