Fecal peritonitis: microbial adherence to serosal mesothelium and resistance to peritoneal lavage

Fecal contamination of the peritoneal cavity is a serious and potentially life-threatening event. While numerous models have been developed to study the pathogenesis of intraabdominal infection, to date, most investigations have failed to focus on the adherence of the contaminants to the serosal mesothelium. In the present investigation, the cecal ligation and puncture technique (CLP) was performed in Sprague-Dawley rats to study the following: (a) the kinetics of microbial adherence to the serosal mesothelium, (b) the stability of the aerobic and anaerobic intraperitoneal/mesothelial populations, following extended saline lavage, and (c) the impact of antimicrobial lavage on the stability of the mesothelial microbial populations. The Enterobacteriaceae rapidly colonized the serosal mesothelium and were the predominant flora up to 4 hours post-CLP. After 8 hours, the Bacteroides fragilis group represented the predominant peritoneal wash and mesothelial-associated microorganisms. Extended saline lavage failed to significantly reduce the mesothelial microbial populations. While antimicrobial lavage produced an immediate decrease in mesothelial microbial recovery, the results were transitory and the microbial populations achieved or exceeded prelavage levels at 24 hours postlavage. Microbial colonization of the peritoneal mesothelial surface is a rapid and stable phenomena following penetrating injury to the distal bowel. The results further suggest that the mesothelial populations are resistant to intraperitoneal lavage.