Translocation of gut bacteria in rats with cirrhosis to mesenteric lymph nodes partially explains the pathogenesis of spontaneous bacterial peritonitis.

Spontaneous bacterial peritonitis is a common infection of ascitic fluid that develops in cirrhosis. The offending organisms are predominantly of enteric origin. However, the mechanism and route by which bacteria exit from the gut and enter the fluid remain unclear. "Translocation" of bacteria from the gut to extraintestinal sites has been postulated in the pathogenesis of gram-negative sepsis in intensive care unit patients, burn-wound sepsis, and sepsis associated with chemotherapy. Translocation is defined by culture-positivity (with enteric flora) of mesenteric lymph nodes. In this study we assessed the frequency of translocation in a carbon tetrachloride-induced rat model of cirrhosis, ascites, and spontaneous bacterial peritonitis. We determined that translocation was more common in rats with cirrhosis (78.1%) than in normal controls (4.3%) (p < 0.001). Escherichia coli and other gram-negative enteric organisms were cultured. Translocation of enteric bacteria in rats with cirrhosis to extraintestinal sites may be an important early step in the pathogenesis of spontaneous bacterial peritonitis.