The rat model of endocarditis

The rat model of endocarditis is a well established experimental protocol which closely approximates human native valve endocarditis. The rat model of endocarditis has been used to examine the role of particular streptococcal virulence factors, to assess immunoprotective strategies, and to evaluate the efficacy of selected antibiotic treatment regimens for streptococcal endocarditis. Like humans, rats are generally susceptible to endocarditis only if the cardiac valves have been damaged. In the rat model of endocarditis, damage to the aortic valve and sterile vegetation formation is accomplished by insertion of a polyethylene catheter through the carotid artery into the left ventricle. Following catheter insertion, an inoculum of streptococci are injected intravenously. Vegetations removed from the heart valves during thoracotomy of euthanized animals are qualitatively cultured for streptococcal infection. The method, including investigator safety considerations, is described in detail.