Brain abscess associated with Aggregatibacter actinomycetemcomitans: case report and review of literature

Introduction: Aggregatibacter actinomycetemcomitans is considered a major pathogen in localized and generalized aggressive periodontitis. A. actinomycetemcomitans has been found in various extra oral infections and most frequently in endocarditis. We report a patient with multiple brain abscesses due to infection with A. actinomycetemcomitans and review the English language literature related to this subject. Case report: A 42-year-old patient with no underlying medical conditions presented with multiple brain lesions initially thought to be metastatic lesions of a tumour of unknown origin. Findings during drainage and subsequent histopathological conclusions made infection more likely. Culture of drained material remained negative; however, 16S rDNA polymerase chain reaction and sequence analysis on direct material revealed A. actinomycetemcomitans as the causative agent of the infection. The most likely source of infection was the poor dentition of the patient. After repeated drainage of the lesions and antibiotic treatment the patient gradually improved, although cognitive impairment remained. Conclusions: Our report illustrates that a poor dental condition, notably destructive periodontal disease, can be a risk for life-threatening extra oral disease, and thus contributes to the total inflammatory burden of the body.