Short communication: Distribution of Porphyromonas gulae fimA genotypes in oral specimens from dogs with mitral regurgitation

Investigation of periodontal disease development and Porphyromonas gulae FimA genotype distribution in small dogs

In dogs, Porphyromonas gulae is a major periodontal pathogen with 41-kDa proteins polymerizing to form a filamentous structure called fimbriae or pili, termed FimA. FimA is classified into three genotypes: A, B, and C, and there are combinations of types A, B, C, A/B, A/C, B/C, and A/B/C. Periodontal disease is the most common oral disease in small dogs, but the periodontal disease status and P. gulae colonization at each dog age and breed remain unclear. In this study, we stratified 665 small dogs and analyzed the periodontal status and distribution of P. gulae with each FimA genotype. Dogs with periodontal disease and FimA genotype tended to increase with age. The dogs with at least one FimA genotype had significantly more severe periodontal disease compared with P. gulae-negative dogs (P < 0.01). Additionally, periodontal status was significantly associated with specific FimA genotype distribution in Toy Poodles and Chihuahuas (P < 0.05), whereas there was no such association in Dachshunds. These results suggest that the onset of periodontal disease and P. gulae colonization are related and progress with age. The relationship between periodontal disease and FimA genotype may differ depending on the dog breeds.

Periodontal disease in cats under primary veterinary care in the UK: frequency and risk factors

OBJECTIVES

Periodontal disease is a multifactorial inflammatory disease that can have major welfare implications in cats. This study aimed to report the frequency and demographic risk factors of periodontal disease and to explore associations with common comorbid disorders in cats in the UK.

METHODS

The study included a random sample of 18,249 cats obtained from 1,255,130 cats under primary care during 2019 from clinics participating in the VetCompass programme. All disorders recorded during 2019 were extracted and reported. Risk factor and comorbid disorder analysis used multivariable logistic regression modelling.

RESULTS

Periodontal disease had a 1-year period prevalence of 15.2% (95% confidence interval [CI] 14.72-15.76). Breeds with the highest prevalence included Siamese (18.7%, 95% CI 12.24-26.72) and Maine Coon (16.7%, 95% CI 11.37-23.18). The median age of cats with periodontal disease (9.47 years, interquartile range [IQR] 5.96-12.97) was higher than for cats without periodontal disease (4.94 years, IQR 1.95-9.51; P <0.001). Increasing adult body weight, increasing age and sex-neuter status were significantly associated with rising odds of periodontal disease. Cats with periodontal disease had a higher median count of comorbid disorders per individual cat (3, IQR 2-4, range 1-14) than cats without periodontal disease (1, IQR 0-2, range 0-15; P <0.001). Cats with periodontal disease had 1.79 times the odds (95% CI 1.62-1.99, P <0.001) of diagnosis with at least one comorbid disorder disease than cats without periodontal disease.

CONCLUSIONS AND RELEVANCE

Periodontal disease is the most common specific diagnosis in cats and is confirmed as a leading health issue in cats. Ageing is identified as the strongest predictor of periodontal disease risk in cats, suggesting the potential for increasing health gains from emphasis on dental care and health in cats as they age. The study offers evidence on a close link between periodontal disease and reduced overall health in cats.

Possible association of fimA genotype of Porphyromonas gulae with the severity of periodontal disease and the number of permanent teeth in dogs

Previous research has demonstrated that Porphyromonas gulae (P. gulae) significantly contributes to the development of periodontal disease in dogs. Porphyromonas gulae is divided into three subtypes according to the 41-kDa filamentous appendage (fimA), defined as types A, B, and C. This study aimed to elucidate the association between fimA type of P. gulae with the number of permanent teeth, reflecting the severity of periodontal disease. Two hundred twenty-five dogs were categorized by P. gulae fimA type as negative, type A dominant, type B dominant, and type C dominant. The stage of periodontal disease in P. gulae-positive dogs increased with age, particularly in type C dominant dogs. Correspondingly, the number of permanent teeth in P. gulae fimA type C-dominant dogs was significantly lower than that of P. gulae-negative dogs, suggesting there is a significant association between fimA type of P. gulae and the number of permanent teeth resulting from the development of periodontal disease.

Delivery of active minocycline hydrochloride by local sustained-release system of complex and thermoresponsive hydrogel for dogs

ABSTRACT The objective of this study was to develop a novel subgingival sustained-release system for local delivery of bioactive minocycline hydrochloride for periodontal disease treatment in dogs. The system incorporated the Minocycline hydrochloride-Calcium-Dextran sulfate sodium into a thermoresponsive Pluronic F127 hydrogel. Minocycline hydrochloride was sustained release from the system for up to 10 days and the release kinetics fit the power law model. The release medium had a significant statistical difference in antimicrobial activity to Aggregatibacter actinomycetemcomitans. The results showed the system was a promising subgingival sustained-release minocycline hydrochloride delivery system for periodontal disease treatment in dogs.

Inhibition of Porphyromonas gulae and periodontal disease in dogs by a combination of clindamycin and interferon alpha

Porphyromonas gulae is a major periodontal pathogen in dogs, which can be transmitted to their owners. A major virulence factor of P. gulae consists of a 41-kDa filamentous appendage (FimA) on the cell surface, which is classified into three genotypes: A, B, and C. Thus far, inhibition of periodontal disease in dogs remains difficult. The present study assessed the inhibitory effects of a combination of clindamycin and interferon alpha (IFN-α) formulation against P. gulae and periodontal disease. Growth of P. gulae was significantly inhibited by clindamycin; this inhibition had a greater effect on type C P. gulae than on type A and B isolates. In contrast, the IFN-α formulation inhibited the expression of IL-1β and COX-2 elicited by type A and B isolates, but not that elicited by type C isolates. Furthermore, periodontal recovery was promoted by the administration of both clindamycin and IFN-α formulation to dogs undergoing periodontal treatment; moreover, this combined treatment reduced the number of FimA genotypes in oral specimens from treated dogs. These results suggest that a combination of clindamycin and IFN-α formulation inhibit P. gulae virulence and thus may be effective for the prevention of periodontal disease induced by P. gulae.

Relation between periodontal disease and systemic diseases in dogs

Periodontal disease (PD) is one of the most frequent and widespread inflammatory diseases in dogs. The onset of PD pathogenesis is prompted by the dental microbial biofilm combined with the animal immune-inflammatory response. Along with local effects, systemic consequences can occur secondary to dental plaque-associated bacteraemia, affecting distant tissues and organs. The main goal of this retrospective study was to access and evaluate the association between PD and systemic consequences (renal, hepatic and cardiac) in a group of 136 dogs. Clinical records of all animals were assessed for general and systemic information, further analysed by general linear model and Odds-Ratio. Animals were organized in two groups, PD group and control group, formed by animals without PD. In this population, increasing age was proven to be a risk factor (OR = 1.04, p < .01) for PD establishment. Small breeds (<10 Kg) were the most prevalent in the PD group, being more susceptible to this disease. On the other hand, no influence of gender or reproductive status in PD progression was observed. Regarding systemic diseases, a statistically significant association (p = .026) was obtained between PD and cardiac disease. Results show that PD can have a significant adverse impact on animals' health, being related with systemic consequences, which may increase morbidity and mortality rates of these animals. PD prevention, with focus on owner's information about this disease and its management, are essential points for an active PD control program.

Potential involvement of Helicobacter pylori from oral specimens in overweight body-mass index

The bacterium Helicobacter pylori was originally classified in the Campylobacter genus, which contains major periodontopathic bacterial species, and H. pylori DNA has been found in the oral cavity. Although many studies show an association between the presence of periodontal bacteria and an overweight body-mass index (BMI; >25 kg/m²), the relationship between body weight and the presence of H. pylori in the oral cavity has not been demonstrated. Herein, we analysed the relationship between H. pylori in the oral cavity and systemic conditions, including the overweight BMI. Saliva specimens and extracted teeth were obtained from 87 subjects; the distribution of H. pylori among these specimens was analysed with the polymerase chain reaction. Subjects with an overweight BMI exhibited significantly higher detection rates of H. pylori in saliva, compared with non-overweight subjects (BMI <25 kg/m²) (P < 0.05). A clinical history of digestive diseases was not associated with the presence of H. pylori in overweight subjects, whereas subjects with both severe dental caries and an overweight BMI showed a higher detection rate of H. pylori in saliva specimens, compared with other groups. These results suggest that the detection of H. pylori in the oral cavity could be associated with the overweight BMI, which was predominant among subjects with severe dental caries.

Adhesion and invasion of gingival epithelial cells by Porphyromonas gulae

Porphyromonas gulae, an animal periodontal pathogen, possess fimbriae classified into three genotypes (A-C) based on the diversity of fimA genes encoding FimA. Accumulating evidence suggests that P. gulae strains with type C fimbriae are more virulent as compared to those with other types. The ability of these organisms to adhere to and invade gingival epithelial cells has yet to be examined. P. gulae showed the greatest levels of adhesion and invasion at a multiplicity of infection of 100 for 90 min. P. gulae type C and some type B strains invaded gingival epithelial cells at significantly greater levels than the other strains, at the same level of efficiency as P. gingivalis with type II fimbriae. Adhesion and invasion of gingival epithelial cells by P. gulae were inhibited by cytochalasin D and sodium azide, indicating the requirements of actin polymerization and energy metabolism for those activities. Invasion within gingival epithelial cells was blocked by staurosporine, whereas those inhibitors showed little effects on adhesion, while nocodazole and cycloheximide had negligible effects on either adhesion or invasion. P. gulae proteases were found to be essential for adhesion and invasion of gingival epithelial cells, while its DNA and RNA, and protein synthesis were unnecessary for those activities. Additionally, α5β1 integrin antibodies significantly inhibited adhesion and invasion by P. gulae. This is the first report to characterize P. gulae adhesion and invasion of human gingival epithelial cells.