Experimental Bacteremia Due to Pseudomonas in Agranulocytic Animals

Abstract

The prominence of bacteremia due to Pseudomonas among neutropenic patients led us to search for an appropriate animal model. We devised such a model in rabbits by feeding them Pseudomonas aeruginosa in their drinking water and then rendering them agranulocytic with nitrogen mustard. As their counts of neutrophils fell, 82 of 91 animals died of overwhelming bacteremia. Of these 91 animals, 51 displayed a curious symptom complex of conjunctivitis, nasal stuffiness, massive facial swelling, and necrotic ulcers of the lip and buccal mucous membranes. The fact that we have never observed this syndrome in neutropenic animals with bacteremia due to Escherichia coli and Klebsiella pneumoniae suggests that there are major pathogenetic differences between Pseudomonas and enteric organisms. This simple, realistic model should be useful in examination of the efficacy of antibiotics and immunotherapy against Pseudomonas in the compromised host.