The susceptibilities of 143 Porphyromonas gingivalis, Prevotella intermedia, and Prevotella nigrescens isolates to 18 antimicrobial agents were tested. All P. gingivalis isolates were susceptible. In contrast, some Prevotella spp. (17%) were resistant to beta-lactams, erythromycin, clindamycin, or tetracycline and carried resistance genes, ermF or tetQ, or beta-lactamases.

Recent studies of healthy human airways have revealed colonization by a distinct commensal bacterial microbiota containing Gram-negative Prevotella spp. However, the immunological properties of these bacteria in the respiratory system remain unknown. Here we compare the innate respiratory immune response to three Gram-negative commensal Prevotella strains (Prevotella melaninogenica, Prevotella ...

A rapid method for presumptive identification of black-pigmented gram-negative anaerobic rods was developed. Using filter paper spot tests for indole production, sialidase, alpha-glucosidase, beta-glucosidase, alpha-fucosidase, and trypsinlike enzyme activities, 100% of Porphyromonas gingivalis, Prevotella intermedia, and Bacteroides levii and 89% of Prevotella corporis isolates were correctly ...

While most bacteria involved in dentoalveolar infection are highly susceptible to penicillin, some Prevotella strains exhibit resistance to this agent through the production of beta-lactamase. The production of beta-lactamase by Prevotella spp. is in turn associated with the expression of the genes cfxA and cfxA2. The aim of the present study was to determine the prevalence of cfxA and cfxA2 in...

Oral Prevotella and Capnocytophaga species, regularly isolated from periodontal pockets and associated with extraoral infections, secret specific immunoglobulin A1 (IgA1) proteases cleaving human IgA1 in the hinge region into intact Fab and Fc fragments. To investigate whether these enzymes are subject to inhibition in vivo in humans, we tested 34 sera from periodontally diseased and healthy in...

Metronidazole resistance among Prevotella spp. is rare. We report here the first case of bacteremia due to a high-level metronidazole-resistant Prevotella sp. responsible for treatment failure.