Antibiotic Susceptibility Testing of Some Prevotella Strains Isolated from Vestibular Abscesses

The aim of this study was to investigate in vitro the antibiotic susceptibility of 53 strains of Prevotella isolated from vestibular abscesses. The E-test was used for determining the minimum inhibitory concentrations for: benzylpenicillin, ampicillin, amoxicillin/clavulanic acid, clindamycin and metronidazole. In addition to this, the beta-lactamase production was detected by the chromogenic cephalosporin test. Most of the strains were susceptible to the tested antibiotics. Twelve strains were resistant to benzylpenicillin and ampicillin due to the production of beta-lactamase. A single isolate of P. buccae presented also resistance to clindamycin. In conclusion, the results of this study recommend the prescription of metronidazole or clindamycin in infections caused by these microorganisms. In case of oral and maxillofacial infections (which are mainly mixed infections), when antimicrobial treatment is necessary but it is done empirically, it might be proper to choose an antibiotic active against beta-lactamase producing bacteria too, such as an association of a penicillin with a beta-lactamase inhibitor.