Colorectal Surgical Site Infections and Their Causative Pathogens: Differences between Left- and Right-Side...

Surgical site infections (SSIs), after colorectal resection, pose a significant burden. Recognition of the spectrum of potentially involved pathogens is crucial for determining correct antibiotic prophylaxis. This study aimed to determine whether the distribution of SSI-associated pathogens depends on the location of the colorectal resection.

We retrospectively categorized 2713 consecutive colon resections as left- or right-side operations, identified patients having concurrent peritonitis or development of postoperative SSIs and peritonitis, and assigned all subcutaneously and intra-abdominally isolated pathogens according to the location of the resection.

Gram-positive cocci (especially enterococci) and gram-negative bacilli (especially Pseudomonas aeruginosa) were isolated more frequently from patients in whom SSIs developed after left-side resections than after right-side resections (52.5% vs. 32.6%, p < 0.01 and 15.9% vs. 6.7%, p < 0.01, respectively); enterococci were the causative organisms in a large percentage of SSIs (46.3%). Moreover, intra-abdominal P. aeruginosa and Candida spp. were isolated more frequently during left-side resections than during right-side operations in patients with peritonitis (15.8% vs. 6.3%, p = 0.02 and 14.3% vs. 5.3%, p = 0.02, respectively).

Our results indicate that differences exist in the distribution of pathogens after left- or right-side colorectal resections. Our data further suggest that gram-positive cocci play an important role in SSIs occurring after colorectal resections; therefore, antibiotic prophylaxis should emphasize their coverage. Further, enterococcal coverage may be especially advantageous during left-side resections.