Effect of Penicillin on the Adherence of Streptococcus sanguis In Vitro and in the Rabbit Model of Endocarditis

摘要: A B S T R C The effect of penicillin treatment Streptococcus sanguis in vitro, on subsequent bacterial density the bloodstream and cardiac valves rabbit model endocarditis was studied. As experimental tools for this study, isogenic pairs S. differing resistance to streptomycin or rifampin were prepared by genetic transformation. Rabbits with traumatized heart received an intravenous inoculation treated (1 ,g/ml) untreated sanguis, each marked either rifampin. number penicillin-treated bacteria attached valvular surfaces determined differential counting containing media. Penicillin pretreatment reduced valve colonization 5 min after ("adherence ratio" X 108 4.11 control 3.66 bacteria, P 0.10). In vitro experiments performed using plateletfibrin test possibility that penicillininduced loss lipoteichoic acid responsible decreased streptococcal adherence. Pretreatment cultures inhibitory concentrations antiserum against precoating platelet-fibrin acid, all caused reduction findings are interpreted as support role adhesin interactions particular host tissue surfaces.