구강 내 세균들과 고양이, 개, 사람의 치주질환의 연관성 연구

다국어 초록 (Multilingual Abstract)

Studies on Oral Bacterial Species for Their Pathogenic Association with Periodontal Disease in Cats, Dogs, and Humans Kisuk BAE Department of Molecular Biology Graduate School Dankook University Advisor：Professor Jonghoe BYUN Periodontal disease is one of the most common oral conditions in both humans and companion animals, including cats and dogs. The disease deteriorates from reversible gingivitis to periodontitis, which leads to irreversible destruction of the periodontal ligament and alveolar bone, eventually resulting in tooth loss and edentulism. Subgingival bacteria, one of etiological factors causing periodontal disease, affects periodontal disease by a complex interaction with host and environmental factors. Although the relationship between these bacteria and periodontal disease has been well-studied in humans, comparable studies in feline and canine remain limited. Prior studies have suggested that bacteria linked to human periodontitis may also contribute to periodontal disease in animals. However, these studies have involved small sample sizes and focused on bacterial prevalence in animals. The objectives of this study were threefold: (1) to analyze the association between periodontal disease and 11–12 putative periodontopathic bacterial species, Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Fusobacterium nucleatum (Fn), Prevotella nigrescens (Pn), Prevotella intermedia (Pi), Parvimonas micra (Pm), Eubacterium nodatum (En), Campylobacter rectus (Cr), and Eikenella corrodens (Ec), or Porphyromonas gulae (P. gulae) using quantitative real-time PCR (qPCR) with 435, 1,054, and 193 samples in cats, dogs, and humans, respectively, and identify interspecies differences; (2) to assess the feasibility of disease classification based on alveolar bone loss measured via panoramic radiography in conjunction with oral bacterial profiling; and (3) to investigate the applicability of non-invasive and simple sampling methods for diagnostic purposes. The relationships and patterns between putative periodontal pathogens and periodontitis were similar and slightly different in dogs and in cats while those were much different from those in animals and in humans. Fn, Tf, Td, Pi, and Pm were significantly associated with periodontal disease in cats and dogs, albeit with distinct patterns from those observed in humans. Aa and P. gulae did not show a statistically significant association with periodontal disease in all species and in cats and dogs, respectively. Conversely, Pg exhibited a strong correlation with periodontal disease in humans but not in companion animals. Additionally, swab-based sampling in animals and mouthwash-based qPCR analysis coupled with panoramic radiography in humans were found to be effective and practical diagnostic methods. The microbial etiology of periodontal disease exhibits both commonalities and species- specific distinctions among cats, dogs, and humans. While Pg remains a powerful biomarker in humans, Fn, Tf, Td, Pi, and Pm show strong diagnostic potential in cats and dogs. Non-invasive sampling tools and radiographic grouping offer simple, effective, feasible methods for diagnosing and classifying periodontal disease in companion animals and humans. Future studies should aim to refine these tools and validate them in clinical populations.

목차 (Table of Contents)

• Ⅰ. Introduction 1
• Ⅱ. Materials and Methods 8
• 2.1 Animals 8
• 2.2 Humans 8
• 2.3 Sample collection of Animals 9
• 2.4 Sample collection of Humans 16
• 2.5 Classification and grouping of Target Teeth and Mouthwash samples by Periodontal Disease Stage 16
• 2.5.1 Animals 16
• 2.5.2 Humans 17
• 2.6 DNA extraction 23
• 2.7 Quantitative real-time PCR (polymerase chain reaction) 23
• 2.8 Data management and statistical analysis 24
• Ⅲ. Results 30
• 3.1 Results 1 30
• 3.1.1 Characteristic profiles of dogs that donated the subgingival plaque samples in dogs 30
• 3.1.2 Prevalence of putative periodontal disease-associated bacteria in dogs 32
• 3.1.3 Comparison of bacterial prevalence between reversible and irreversible groups in dogs 32
• 3.1.4 Mean number of putative periodontal disease-related bacteria in dogs 36
• 3.1.5 Comparison of mean number of bacteria between reversible and irreversible groups in dogs 36
• 3.1.6 Correlation between severity of periodontal disease and age, weight, BOP, mean PPD, and number of bacterial species in dogs 40
• 3.1.7 Association of Aa in all possible between-group comparisons in dogs 40
• 3.1.8 Association of the combined coexistence of age, weight, and the number of bacteria between reversible and irreversible groups in dogs 43
• 3.1.9 Association of the combined coexistence of age, weight, and the number of bacteria between each PD group in dogs 44
• 3.2 Results 2 50
• 3.2.1 Characteristic profiles of dogs and cats that donated the subgingival plaque samples in dogs and cats 50
• 3.2.2 Prevalence of putative periodontal disease-associated bacteria in dogs and cats 52
• 3.2.3 Comparison of bacterial prevalence between reversible and irreversible groups in dogs and cats 52
• 3.2.4 Mean number of putative periodontal disease-related bacteria in dogs and cats 56
• 3.2.5 Comparison of the mean number of bacteria between reversible and irreversible groups in dogs and cats 56
• 3.2.6 Correlation between severity of periodontal disease and age, weight, BOP, mean PPD, and number of bacterial species in dogs and cats 60
• 3.2.7 Association of Aa and Pg in all possible between-group comparisons in dogs and cats 60
• 3.2.8 Association of Aa, Pg, Pn, Pi and En in all possible group comparisons in cats 60
• 3.2.9 Association of the combined coexistence of age, weight, and the number of bacteria between reversible and irreversible groups in dogs and cats 66
• 3.2.10 Association of the combined coexistence of age, weight, and the number of bacteria between each PD group in dogs and cats 66
• 3.2.11 Comparison of sampling methods such as GCF samples and Swap samples of dogs and cats 72
• 3.3 Results 3 75
• 3.3.1 Comparison of correlations between severity of periodontal disease and group of Alveolar bone loss and age, BOP, PPD and the number of each species, except for P. gulae 75
• 3.3.2 Prevalence of putative periodontal disease-associated bacteria, except for P. gulae, in dogs, cats, and humans 78
• 3.3.3 Comparison of bacterial prevalence between reversible and irreversible groups in dogs, cats, and humans, except for P. gulae 78
• 3.3.4 Mean number of putative periodontal disease-related bacteria, except for P. gulae, in dogs, cats, and humans 83
• 3.3.5 Comparison of the mean number of bacteria, except for P. gulae, between reversible and irreversible groups in dogs, cats, and humans 83
• 3.3.6 Correlation between severity of periodontal disease and age, BOP, PPD, and number of bacterial species, except for P. gulae, in dogs, cats, and humans 88
• 3.3.7 Association of the combined coexistence of age, weight, and the number of bacteria except for Aa in dogs and age, weight, Aa, Pg, Pn, Pi, and En in cats and Aa, Ec, and P. gulae in humans, respectively, between reversible and irreversible groups 88
• 3.3.8 Association of the combined coexistence of age, weight, and the number of bacteria except for Aa in dogs and age, weight, Aa, Pg, Pn, Pi, and En in cats and Aa, Ec, and P. gulae in humans, respectively, between PD groups 94
• 3.3.9 Association of the combined coexistence of the number of bacteria of red complex (Pg, Tf, and Td) between reversible and irreversible groups in dogs, cats, and humans 94
• 3.3.10 Summary for the results of combined association of factors in all comparisons 97
• Ⅳ. Discussion 99
• V. Conclusion 118
• References 119
• 국문 초록 129