Severe versus local odontogenic bacterial infections: comparison of microbial isolates.

AIM: It was the aim of this study to evaluate the clinical and microbiological differences between severe and local odontogenic abscesses.
METHODS: Thirty patients were prospectively enrolled. Sixteen of 30 patients suffered from a severe life-threatening abscess of the head and neck, whereas 14/30 patients presented with a localized submucous abscess. Anaerobic bacteria were identified and susceptibility testing was performed using E test strips for penicillin, amoxicillin + clavulanic acid, imipenem + cilastatin, clindamycin and metronidazole.
RESULTS: The mean duration until removal of all drains was 14.1 and 3.5 days, respectively. Anaerobic bacteria were found in all episodes of local abscesses, whereas 19% of the severe episodes were culture negative, and in 13%, only aerobes were identified. A total of 60 anaerobes were isolated from 27 patients (2.2 isolates/positive sample). The dominating species were Prevotella sp. (n = 17), Peptostreptococcus sp. (n = 15) and Propionibacterium sp. (n = 5). Eighty-seven percent of the isolates were susceptible to penicillin. Ninety-seven percent of the anaerobes were susceptible to amoxicillin + clavulanic acid, imipenem + cilastatin, and clindamycin. Eighty-three percent were susceptible to metronidazol. There was a tendency for a higher rate of episodes with penicillin-resistant bacteria in the patients with severe abscesses (14 vs. 31%). No difference in susceptibility regarding amoxicillin + clavulanic acid and clindamycin (7%) was observed. Copyright 2008 S. Karger AG, Basel.