Experimental Endocarditis Due to Pseudomonas aeruginosa. I. Description of a Model

Abstract

Rabbits with sterile, right ventricular cardiac vegetations were challenged with Staphylococcus aureus arid serum-susceptible or -resistant isolates of Pseudomonas aeruginosa. None of the rabbits challenged with serum-susceptible P. aeruginosa died or had >10² colony-forming units (cfu)/g cultured from vegetations two weeks later. In contrast, 78% of animals challenged with serum-resistant P. aeruginosa died within three weeks, and 74% sacrificed at three days had organisms cultured from vegetations. All of the animals challenged with S. aureus died, and all had >10⁸ cfu of P. aeruginosa/g in vegetation tissue at three days. There was a significantly greater number of organisms (P < 0.001) in the vegetations of animals dying of S. aureus infection than in those of animals with P. aeruginosa endocarditis (mean, 10^9.6 vs. 10^7.5 cfu/g, respectively). Left-sided endocarditis was produced in 100% of rabbits injected with serum-resistant P. aeruginosa. These models could be used for studies of the pathogenesis and therapy of P. aeruginosa endocarditis.