MICROBIOLOGY OF BACTERIAL TRANSLOCATION IN HUMANS

Background-Gut translocation of bacteria has been shown in both animal and human studies. Evidence from animal studies that links bacterial translocation to the development of postoperative sepsis and multiple organ failure has yet to be confirmed in humans. Aims-To examine the s pectrum of bacteria involved in translocation in surgical patients und ergoing laparotomy and to determine the relation between nodal migrati on of bacteria and the development of postoperative septic complicatio ns.Methods-Mesenteric lymph nodes (MLN), serosal scrapings, and periph eral blood from 448 surgical patients undergoing laparotomy were analy sed using standard microbiological techniques. Results-Bacterial trans location was identified in 69 patients (15.4%). The most common organi sm identified was Escherichia coli (54%). Both enteric bacteria, typic al of indigenous intestinal flora, and non-enteric bacteria were isola ted. Postoperative septic complications developed in 104 patients (23% ). Enteric organisms were responsible in 74% of patients. Forty one pe r cent of patients who had evidence of bacterial translocation develop ed sepsis compared with 14% in whom no organisms were cultured (p<0.00 1). Septic morbidity was more frequent when a greater diversity of bac teria resided within the MLN, but this was not statistically significa nt. Conclusion-Bacterial translocation is associated with a significan t increase in the development of postoperative sepsis in surgical pati ents. The organisms responsible for septic morbidity are similar in sp ectrum to those observed in the mesenteric lymph nodes. These data str ongly support the gut origin hypothesis of sepsis in humans.