Early Canine Plaque Biofilms: Characterization of Key Bacterial Interactions Involved in Initial Colonization of Enamel

Abstract

Periodontal disease (PD) is a significant problem in dogs affecting between 44% and 63.6% of the population. The main etiological agent for PD is plaque, a microbial biofilm that colonizes teeth and causes inflammation of the gingiva. Understanding how this biofilm initiates on the tooth surface is of central importance in developing interventions against PD. Although the stages of plaque development on human teeth have been well characterized little is known about how canine plaque develops. Recent studies of the canine oral microbiome have revealed distinct differences between the canine and human oral environments and the bacterial communities they support, particularly with respect to healthy plaque. These differences mean knowledge about the nature of plaque formation in humans may not be directly translatable to dogs. The aim of this study was to identify the bacterial species important in the early stages of canine plaque formation in vivo and then use isolates of these species in a laboratory biofilm model to develop an understanding of the sequential processes which take place during the initial colonization of enamel. Supra-gingival plaque samples were collected from 12 dogs at 24 and 48 hour time points following a full mouth descale and polish. Pyrosequencing of the 16S rDNA identified 134 operational taxonomic units after statistical analysis. The species with the highest relative abundance were Bergeyella zoohelcum, Neisseria shayeganii and a Moraxella species. Streptococcal species, which tend to dominate early human plaque biofilms, had very low relative abundance. In vitro testing of biofilm formation identified five primary colonizer species, three of which belonged to the genus Neisseria. Using these pioneer bacteria as a starting point, viable two and three species communities were developed. Combining in vivo and in vitro data has led us to construct novel models of how the early canine plaque biofilm develops.

A longitudinal assessment of changes in bacterial community composition associated with the development of periodontal disease in dogs

“…Moraxella and Bergeyella were also observed in healthy dogs in a recent 454-pyrosequencing study of six dogs (Sturgeon et al, 2013). Furthermore, B. zoohelcum, N. shayeganii and a Moraxella species were shown to have the highest relative abundance in early biofilms (Holcombe et al, 2014). Bacterial associations that were positively associated with the development of early periodontitis were less obvious.…”

The canine oral microbiome: variation in bacterial populations across different niches

“…Supragingival plaque, which accumulates on teeth above the gum line, has also received some attention to understand relatedness to subgingival plaque and identify initial bacterial colonisers [9][10][11][12]. The potential microbial contribution of other niches within the canine oral cavity and associated risk to periodontal disease beyond subgingival plaque, however, remains unexplored.…”

Molecular detection of antibiotic resistance genes in multidrug-resistant Staphylococcus aureus isolates from dog dental plaque

“…In one study, the most prevalent species among canine oral microbiome were Bergeyella zoohelcum, Neisseria shayeganii and Moraxella spp. (Holcombe et al, 2014). S. aureus is an opportunistic pathogen colonising the teeth of patients, in the form of biofilm (Ansari et al, 2011).…”