Obligate anaerobic bacteria in pleuropulmonary suppurations.

Anaerobic bacteria are involved in 60%, 80% and 45%, respectively, of lung abscesses, aspiration pneumonias and empyemas. These infections are furthered by a series of elements: poor general condition; local factors such as aspiration syndrome, bronchial obstruction, and tissue necrosis; and high bacterial inoculum, usually from a gingival or sinus infection. Microorganisms involved are Prevotella, Peptostreptococcus sp, Fusobacterium sp, Porphyromonas sp, and less frequently Bacteroides fragilis. Polymicrobial infections are frequent. Suggested by radiologic and clinical findings, diagnosis should be confirmed by rigourous sampling and bacteriological methods. The first signs of a pleuropulmonary suppuration may mimic a community-acquired pneumonia. However; the initiating role of anaerobic bacteria in this condition remains controversial. (C) 2000 Editions scientifiques et medicales Elsevier SAS.