[Endocarditis caused by Haemophilus parainfluenzae and Neisseria gonorrhoeae]

Infective endocarditis due to gramnegative bacteria is rare. Overall, its relative frequency seems to be much lower than 10 percent. According to the extensive literature reviewed most often the causative microorganisms belong to the families of enterobacteriaceae and pseudomonads. Extremely rare, however, are cases where certain fastidious gramnegative bacteria such as hemophili, neisseria and others are the causative organisms. We report two cases of infective endocarditis due to Haemophilus parainfluenzae and to Neisseria gonorrhoeae. Despite their fastidious growth, both organisms could rapidly be isolated from venous blood cultures. Both were sensitive to ampicillin or penicillin respectively, and adequate antimicrobial therapy could early be initiated. As compared to reports in the literature both cases showed typical valve involvement and took a relatively typical course under medical treatment. The Haemophilus parainfluenzae endocarditis presented as a subacute illness following a tooth extraction and showed large vegetations on a prolapsed mitral valve. In contrast to the findings of others signs of slight renal involvement but no signs of major arterial embolization were noted. Medical treatment with ampicillin plus an aminoglycoside was effective as in most other reported cases. Vegetations were echocardiographically no longer seen after five weeks. The gonococcal endocarditis early led to destructive lesions of the aortic valve, significant regurgitation, vascular congestion and complicating pneumonia. Medical treatment alone was not effective despite the high susceptibility to antibiotics ot the strain isolated. As reported für the majority of cases reviewed in the literature early valve replacement became necessary for a favourable outcome.