OOPs III Diagnostic Agars Inoculated with Human Saliva

Objectives: To determine the identity of dark pigmented colonies from human saliva growing on OOPs III agar with and without 5% sheep blood, which is diagnostic for organisms producing malodorous volatile sulfur containing compounds (VSCs). Methods: Human saliva collected from several donors was pooled, diluted and plated on pre-reduced OOPs III diagnostic agars and incubated anaerobically for a minimum of 5 days at 35ºC (+/- 2OC) . Dark pigmented, VSC-producing colonies were isolated and streaked on pre-reduced Schaedler Blood Agar (SBA) and OOPs III diagnostic agars and incubated anaerobically at 35ºC (+/-2OC) for 5 days. An additional set of plates was incubated aerobically under the same conditions. Digital pictures were taken of the plates. Isolates were Gram stained and identified using one of the following identification systems: Rapid Ana II (Remel) or Vitek (BioMerieux). As a reference, selected organisms from an established oral care culture collection were grown on the same set of media and incubated under the same conditions. Results: To date, Fusobacterium necrophorum, Campylobacter gracilis, and Prevotella corporis have been identified from human saliva on OOPs III diagnostic agar. Bacteroides caccae, Campylobacter gracilis and Bacteroides fragilis have been identified form human saliva on OOPs III diagnostic agar with 5% sheep blood. Dark and light colored colonies were identified from the reference organisms. They included: Fusobacterium nucleatum, Eikenella corrodens, Veillonella parvula and Veillonella dispar (dark), and Actinomyces odontolyticus and Actinomyces naeslundii (light). Conclusion: VSC- producing organisms isolated from OOPs III diagnostic agars have been identified as species that are linked to oral malodor by other investigators. This study further supports the use of this media for studies on oral malodor-associated species.