and its potential role as a caries pathogen.

Background: has been strongly associated with dental caries but caries also occurs in its absence. Association of a new species, with childhood caries suggests this could be a new caries pathogen.

Highlight: is considered a caries pathogen based on its association with caries, and on its ability to produce acid, to survive low pH environments, and to induce caries in experimental animals. was significantly associated with severe-early childhood caries in the presence and absence of . Further was elevated in initial carious lesions in adolescents with fixed orthodontic appliances. detection was enriched on a low pH agar suggesting acid-tolerance. isolates were acid tolerant and produced acid from several sugars at low initial pH values, and were not arginine deiminase positive, characteristics consistent with potential cariogenicity. Cariogenicity of was tested in a rat animal model in parallel with While by itself showed minimal caries induction, when co-inoculated with , there was significant cavity production.

Conclusion: was associated with advanced and initial caries, is acid tolerant and produces acid to low pH at initial neutral and low pH conditions. In combination with , was detected in caries in an animal model. Together, these data suggest that has many of the characteristics consistent with its being a caries-associated species.