Anaerobic infections of the abdomen and pelvis
Recently, there has been an increased awareness of the role of anaerobes in clinical infections. The purpose of this paper is to emphasize the frequency with which anaerobes are involved in infections of the abdomen and pelvis, and to illustrate some of the clinical problems.
First, I would like to present data from an excellent study by Gorbach et al.1 Forty-six cases were studied; predisposing conditions included abdominal trauma (22 patients), carcinoma (7 patients), postoperative infections (7 patients), perforated appendix (4 patients), hepatic cirrhosis (3 patients), and peritoneal dialysis (3 patients). Thirty-two patients had intraabdominal abscesses, 10 had generalized peritonitis, and four had miscellaneous conditions (retroperitoneal and prostatic abscesses, infected aortic graft). Of 43 specimens of purulent abdominal material studied, 33 yielded both anaerobes and aerobes, seven grew anaerobes alone and in three, only aerobes were isolated. There was an average of five organisms per specimen (range 1 to 13), with a ratio of three anaerobes to two aerobes. Each organism had to be obtained in pure culture in order to be accurately identified, a time-consuming process with anaerobes, which often grow slowly.
The specific organisms are listed in Table 1. Gram-negative nonsporeforming anaerobic rods predominated, reflecting the fact that Bacteroides fragilis is the most prevalent member of the normal flora of the bowel. This organism was isolated 28 times along with small numbers of other gram-negative nonsporeforming anaerobes of the genus Bacteroides and of the genus Fusobacterium. Of special significance is the fact that B. fragilis is much more. . .