title: Prevalence of beta-lactamase-producing strains among 149 anaerobic gram-negative rods isolated from periodontal pockets.
abstract: In a prospective study, 47 adults presenting a rapidly progressive periodontitis were selected in order to evaluate the prevalence of beta-lactamase-producing strains among oral anaerobic gram-negative rods. Predominant anaerobes were identified from two of the deepest periodontal pockets. beta-Lactamase-positive strains fulfilled to at least two of three criteria: positive nitrocefin test, penicillin Etest minimal inhibitory concentration > 1 microgram/ml, and disk diffusion synergy between amoxycillin and clavulanic acid > 10 mm. At least one beta-lactamase-producing strain was found in 53.2% of patients and 39.4% of the periodontal pockets investigated. Prominent beta-lactamase-positive species were Prevotella buccae and Prevotella intermedia (respectively 16 of 38: 42% and 18 of 52: 35% positive strains), followed by Prevotella bivia, Prevotella disiens, Prevotella denticola and Fusobacterium nucleatum (respectively 1 of 6: 17%, 1 of 10: 10%, 1 of 10: 10%, and 1 of 13: 8% positive strains). No beta-lactamase producer could be evidenced in Porphyromonas gingivalis (10 strains tested). All the beta-lactamase-positive strains with the nitrocefin test had penicillin minimal inhibitory concentrations > 1 microgram/ml with the Etest, and a strong synergy between amoxicillin and clavulanic acid was always observed.
authors.affiliation: Laboratoire de Bactériologie, Hôpital l'Archet 2, CHU de Nice, France.
authors.forename: T
authors.initials: T
authors.lastname: Fosse
authors.forename: I
authors.initials: I
authors.lastname: Madinier
authors.forename: C
authors.initials: C
authors.lastname: Hitzig
authors.forename: Y
authors.initials: Y
authors.lastname: Charbit
mesh_terms: D000328:Adult; D001426:Bacterial Proteins / Q000096:biosynthesis*; D016967:Fusobacterium nucleatum / Q000201:enzymology; D016965:Gram-Negative Anaerobic Straight, Curved, and Helical Rods / Q000201:enzymology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D010403:Penicillin Resistance; D010514:Periodontal Pocket / Q000382:microbiology*; D018720:Prevotella / Q000201:enzymology; D011446:Prospective Studies; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D001426:Bacterial Proteins; D001618:beta-Lactamases