Oral bacteria in infective endocarditis requiring surgery: a retrospective analysis of 134 patients

Objectives It has been reported that bacteria associated with infective endocarditis originate from the oral cavity in 26-45% of cases. However, little is known on the counts and species of periodontal microbiota in infected heart valves. The aim of this study was to identify these aspects of periodontal microbiota in infective endocarditis and to potentially initiate a dental extraction concept for periodontally compromised teeth concerning patients requiring heart valve surgery. Materials and methods The retrospective study group consisted of tissue samples from infected heart valves of 683 patients who had undergone heart valve surgery. Before patients had undergone cardiac surgery, the following laboratory tests confirmed the occurrence of endocarditis in all patients: blood cultures, echocardiography, electrocardiography, chest X-ray, and electrophoresis of the serum proteins. The specimens were aseptically obtained and deep frozen immediately following surgery. Microbiological diagnosis included proof of germs (dichotomous), species of germs, and source of germs (oral versus other). Results Microbiota was detected in 134 (31.2%) out of 430 enrolled patients. Oral cavity was supposed to be the source in 10.4% of cases, whereas microbiota of the skin (57.5%) and gastrointestinal tract (GIT, 24.6%) were detected considerably more frequently. Moreover, periodontal bacteria belonged mostly to the Streptococci species and the yellow complex. None of the detected bacteria belonged to the red complex. Conclusion Most frequently, the skin and GIT represented the site of origin of the microbiota. Nevertheless, the oral cavity represented the source of IE in up to 10%. Consequently, it needs to be emphasized that a good level of oral hygiene is strongly recommended in all patients undergoing heart valve surgery in order to reduce the bacterial load in the oral cavity, thereby minimizing the hematogenous spread of oral microbiota. The prerequisites for conservative dental treatment versus radical tooth extraction must always be based on the patient's cooperation, and the clinical intraoral status on a sense of proportion in view of the overall clinical situation due to the underlying cardiac disease.