Evaluation of the impact of dental prophylaxis on the oral microbiota of dogs - Fig 6

<p><b>Principal coordinate analysis (PCoA) of all time points for (a) plaque microbiota community structure, and (b) oral microbiota community membership (n = 10).</b> The plots denote 60% ellipsoid coverage and timepoints are represented by red (Pre), blue (1Week), green (2Weeks), and yellow (5Weeks).</p

Yue and Clayton index dendrogram of bacterial structure (n = 30).

<p>Plaque samples (purple) and oral samples (orange).</p

Evaluation of the impact of dental prophylaxis on the oral microbiota of dogs

<div><p>Periodontal disease is one of the most commonly diagnosed oral diseases in dogs and can result from undisturbed dental plaque. Dental prophylaxis is a routinely practiced veterinary procedure, but its effects on both the plaque and oral microbiota is not fully understood. The objectives of this study were to evaluate the impact of dental prophylaxis on the composition of the supragingival plaque and composite oral microbiota in clinically healthy dogs and to determine if composite sampling could be used in lieu of sampling the plaque microbiota directly. Thirty dogs received a dental prophylaxis. Supragingival plaque and composite oral samples were collected just prior to, and one week after dental prophylaxis. A subsample of 10 dogs was followed, and additional samples were collected two and five weeks post-prophylaxis. The V4 region of the 16S rRNA gene was used for Illumina MiSeq next-generation sequencing. Results demonstrate that decreases in <i>Treponema</i> as well as increases in <i>Moraxella</i> and <i>Neisseria</i> distinguished the plaque pre- and one week post-prophylaxis timepoints (all P<0.05). Within the oral microbiota, the initially dominant <i>Psychrobacter</i> (20% relative abundance) disappeared one week later (P<0.0001), and <i>Pseudomonas</i> became the dominant taxon one week after treatment (80% relative abundance, P<0.0001). A rapid transition back towards the pre-dental prophylaxis microbiota by five weeks post-treatment was seen for both niches, suggesting the canine oral microbiota is resilient. Direct comparison of the two environments yielded striking differences, with complete separation of groups. Firmicutes (40%) and Spirochaetes (22%) predominated in the plaque while Proteobacteria (58%) was predominant in the oral microbiota. Greater richness was also seen in the plaque microbiota. This study reveals that prophylaxis had a profound impact on both the plaque and oral microbiota, and the longitudinal results help elucidate the pathophysiology of periodontal disease. The results suggest that oral swabs are a poor proxy for plaque samples and highlight the need to study specific oral niches.</p></div

Pre-prophylaxis median percent relative abundances of bacterial phyla for plaque and oral microbiota samples (n = 30).

<p>Median relative abundance ≥ 0.5%.</p

Plaque alpha diversity at all time points (n = 10).

<p>Quantile boxplots of (a) Good’s Coverage, (b) Chao’s Richness, (c) Shannon’s Evenness, and (d) Inverse Simpson’s Diversity. Significant differences were seen for parts (c) and (d) between the pre-prophylaxis time points and the end of the study (<i>P</i> < 0.01).</p

Evaluation of the impact of dental prophylaxis on the oral microbiota of dogs - Fig 3

<p><b>Median percent relative abundances of bacterial phyla for (a) plaque and (b) oral microbiota samples (n = 10).</b> All study time points comparisons. Median relative abundance ≥ 0.5%. Refer to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0199676#pone.0199676.s005" target="_blank">S3 Table</a> for <i>P</i>-values.</p

Unweighted UniFrac test values for the Jaccard and the Yue and Clayton community index analyses of the plaque and oral microbiota (n = 10).

<p>Unweighted UniFrac test values for the Jaccard and the Yue and Clayton community index analyses of the plaque and oral microbiota (n = 10).</p

Oral microbiota alpha diversity at all time points (n = 10).

<p>Quantile boxplots of (a) Good’s Coverage, (b) Chao’s Richness, (c) Shannon’s Evenness, and (d) Inverse Simpson’s Diversity. Significant differences were seen for the Pre-1Week, Pre-2Weeks, 1Week-5Weeks, and 2Weeks-5Weeks time points comparisons, for (b), (c), and (d) (<i>P</i> < 0.006 for all comparisons).</p

LEfSe (LDA score ≥ 3.5) identifying genera that were enriched in the plaque and oral microbiotas at the pre and one week post-dental prophylaxis timepoints (n = 30).

<p>LEfSe (LDA score ≥ 3.5) identifying genera that were enriched in the plaque and oral microbiotas at the pre and one week post-dental prophylaxis timepoints (n = 30).</p

Median percent relative abundances of bacterial phyla for (a) plaque and (b) oral microbiota samples (n = 30).

<p>Pre and 1Week time points comparisons. Median relative abundance ≥ 0.5%. (a) Actinobacteria, Proteobacteria, and Spirochaetes were statistically significant between the two timepoints (<i>P</i>_FDR ≤ 0.003); (b) Acintobacteria, Bacteroidetes, Firmicutes, Proteobacteria, and Spirochaetes were statistically significant (<i>P</i>_FDR < 0.0001).</p