Salmonella infection of the biliary and intestinal tract of wild opossums.

Bacteriologic cultures were taken from the mesenteric lymph nodes, biliary tract, blood, liver, spleen and pancreas of opossums (Didelphis virginiana) obtained directly from the wild for use as research animals. The overall incidence of salmonellosis outside the intestinal tract was 61% among 18 opossums. Salmonella was recovered from the gallbladder of six (33%) animals, indicating chronic biliary tract infection. Among these six animals, translocation of Salmonella to regional lymph nodes was observed in five animals, bacteremia in three animals, and spread to liver or spleen in five animals, respectively. The biliary tract was sterile in 12 opossums (67%). In these 12 animals, bacteria were isolated from the celiac and superior mesenteric lymph nodes of five animals, the blood of two animals, and the liver and spleen of one animal, respectively. Bacteriologic cultures were obtained from the intestinal tract and from extraintestinal sites in nine opossums. Salmonella were found in the small bowel of two animals, both of which had biliary salmonellosis. In addition, Salmonella was isolated from extraintestinal organs of three animals with negative cultures from the gut. All isolates identified were: S. enterica subsp houtenae. These data establish the biliary tract of wild opossums as a reservoir for Salmonella enterica subsp houtenae which may be particularly important when opossums are used in research laboratories.