Bacterial translocation in chronic portal hypertensive and common bile duct-ligated growing rats

Abstract

Spontaneous bacteremias and infectious complications occur in patients with chronic portal hypertension (PH) and obstructive jaundice, and most of these infections are caused by indigenous intestinal bacteria translocating to regional lymph nodes and the systemic circulation. The aim of this study was to investigate bacterial translocation (BT) at two stages: (1) isolated chronic PH; and (2) obstructive jaundice. Four-week-old male rats were either subjected to sham laparotomy (SL) or to pH or common bile duct ligation (CBDL). After 4 weeks, animals were weighed and the portal pressure was measured. Samples from the portal vein (PV), vena cava, liver, spleen, mesenteric lymph nodes (MLN), and ileum were obtained for bacteriologic cultures. Specimens from the liver, jejunum, and ileum were taken for histologic examination. Portal pressure increased from 7.4±0.3 to 20.5±0.6 mmHg in PH and CBDL animals (P <0.01). Bacterial cultures obtained from the ileum showed significant bacterial overgrowth (P <0.01) in pH and CBDL rats (1.3±0.8 × 10(4) after SL; 1.2±0.6 × 10(5) in PH and 1.9±0.6 × 10(6) in CBDL). BT occured in 10% of SL animals to the MLN and spleen. In PH animals 23% positive cultures were found, almost all due to BT to the PV, vena cava, and liver. CBDL resulted in a BT rate of 47%, mainly by translocation to the PV, liver, and MLN (P <0.05 vs. SL). Histomorphologically, the jejunum and ileum were normal in all three groups. These results suggest that in growing PH and CBDL rats intestinal bacterial overgrowth with significant BT occurs, and the incidence of BT seems to be related to the amount of bacteria colonizing the intestinal tract.