[Experimental study of bacterial adherence to biliary tract in rabbits]

Adherence to host tissues and cell surfaces is an early step in infections. However nothing has been reported about bacterial adherence in biliary infections. The following experiment was carried out in rabbits with Escherichia coli isolated from the bile of a patient with acute suppurative cholangitis. Adhesion was observed by scanning electron microscopy. First, with cholecystic mucosa of normal, jaundice, acid (mucosa was injured with 0.1 N hydrochloric acid) and stone groups (stones were inserted into the gallbladder), bacterial adhesion as a virulence factor was examined in vitro. Second, in a cholangitis model the role of bacterial adherence to the bile duct in the development of localized biliary infection was examined in vivo.

(1) As compared to the normal, jaundice and stone groups, the number of adhering bacteria was remarkably increased in the acid group. The mucosa of the former groups was relatively intact, but that of the latter was remarkably destroyed. (2) In the cholangitis model, the number of bacteria adhered to the bile duct was negatively correlated with that of bacteria isolated from blood. These results suggest that bacterial adherence to the biliary tract is an important virulence factor, but not in the development from localized cholangitis to sepsis.