The subgingival microbial community of feline periodontitis and gingivostomatitis: characterization and comparison between diseased and healthy cats

Abstract

Periodontitis is a common and important health problem in domestic cats. The subgingival microbiota of cats diagnosed with chronic periodontitis (CP), aggressive periodontitis (AP), and feline chronic gingivostomatitis (FCGS) are not well characterized. Thus, the aim of the present study was to characterize and compare the periodontal microbiota of periodontally healthy cats versus cats diagnosed with CP, AP, and FCGS by using next-generation sequencing. In total, 44 domestic cats were enrolled, and 139 subgingival samples were subjected to 16S rRNA gene sequencing to investigate the microbiota composition of each periodontal group evaluated. Our results identified several key genera previously described in periodontal disease (e.g. Treponema and Filifactor) and in the oral microbiota (e.g. Moraxella and Capnocytophaga) of healthy cats. Phylogenetic beta diversity analysis showed that the microbiota of periodontally healthy cats were distinguishable from diseased cats. Even though most of the genera known to be associated with periodontal disease were also identified in healthy cats, they were present at significantly lower relative abundance. Remarkably, alpha diversity was found to be higher in the disease groups compared to healthy animals. These results suggest a pathological mechanism involving opportunistic behavior. Our findings corroborate those in the current literature regarding the complexity of the subgingival microbiota of the domestic cat and reveal both differences and similarities among periodontally healthy and diseased cats.

Figure 1

Relative abundance (%) of the most abundant bacterial phyla identified in healthy cats and in cats affected with chronic periodontitis (CP), aggressive periodontitis (AP), and feline chronic gingivostomatitis (FCGS).

Figure 2

Box and whiskers plots illustrating the median, quartiles, maximum and minimum of relative abundance of bacteria genera found with significantly higher abundance in diseased cats compared with healthy cats. The genera shown were found to be significant based on screening analysis (FDR P-value < 0.1) using the fifty most abundant genera. P-value indicates significant difference between groups using Dunn method (P < 0.05). *P-value not significant using Dunn method. CP = Chronic Periodontitis; AP = Aggressive Periodontitis; FCGS = Feline Chronic Gingivostomatitis.

Figure 3

Box and whiskers plots illustrating the median, quartiles, maximum and minimum of relative abundance of bacteria genera found with significantly lower abundance in diseased cats compared with healthy cats. The genera shown were found to be significant based on screening analysis (FDR P-value < 0.1) using the fifty most abundant genera. P-value indicates significant difference between groups using Dunn method (P < 0.05). *P- value not significant using Dunn method. CP = Chronic Periodontitis; AP = Aggressive Periodontitis; FCGS = Feline Chronic Gingivostomatitis.

Figure 4

Box and whiskers plots illustrating median, quartiles, maximum and minimum values of the Chao1 richness index and the Shannon diversity index for the different periodontal statuses in cats. Different letters indicate significant differences between periodontal statuses using the Tukey–Kramer test (P-value < 0.05). CP = Chronic Periodontitis; AP = Aggressive Periodontitis; FCGS = Feline Chronic Gingivostomatitis.

Figure 5

Beta diversity analysis of microbial communities of subgingival samples from healthy cats (yellow points) and cats affected with chronic periodontitis (CP; blue points), aggressive periodontitis (AP; orange points), and feline chronic gingivostomatitis (FCGS; green points). (A) Principal coordinate analysis (PCoA) based on unweighted (OTU presence/absence) UniFrac distances metrics (P-value = 0.001; R-squared = 0.103); (B) PCoA based on weighted (OTU abundances) UniFrac distance metrics (P-value = 0.001; R-squared = 0.13). In the parentheses is the variance explained by each PCoA and each point corresponds to a microbial community colored according to type of sample (healthy, AP, CP, and FCGS).