The most frequently isolated gram-negative anaerobes in saliva and subgingival samples taken from young women.

Stimulated saliva and a pooled subgingival sample from the first molars were collected from 30 Caucasian women (mean age 30 years) for the presence of gram-negative anaerobic bacteria. The samples were inoculated on nonselective and selective media. The gram-negative anaerobic species occurring in the oral cavity of more than 50% of the subjects were selected for further analysis. Fusobacterium nucleatum and Prevotella melaninogenica were not recovered from subgingival sites without a simultaneous recovery in saliva. When positive subgingivally, Leptotrichia spp., nonpigmented Prevotella spp., Prevotella intermedia, Capnocytophaga spp., Bacteroides gracilis and Prevotella loescheii were simultaneously detected from saliva in 76%, 72%, 64%, 64%, 61% and 55% of the subjects, respectively. Intraindividually, the proportions of F. nucleatum, nonpigmented Prevotella spp., Leptotrichia spp., B. gracilis and P. loescheii of the anaerobic flora were quite similar in the salivary and subgingival samples. Capnocytophaga spp. and P. intermedia were present in higher proportions in subgingival samples than in saliva, whereas P. melaningogenica was present in higher proportions in saliva. Our data indicate that many oral gram-negative anaerobes are frequently recovered from stimulated saliva. Furthermore, when subgingivally positive, most subjects harbored these anaerobes simultaneously in saliva.