Veterinary session

Feline Tooth Resorption / Feline Odontoclastic Resorptive Lesion (TR/FORL) is a highly prevalent disease of unknown pathogenesis with severe pain in advanced stages. The factors responsible for its development have been investigated for decades but remain unknown. Due to its high prevalence, it is assumed that the causative factors are present in most cats or their environment. Our research was focused on the dysbiosis of the oral microflora, including the role of polyphosphate accumulating (PPA) Lampropedia species. PPA Lampropedia species may affect the local Ca:P balance on the tooth surface and their possible pathogenic role has been suggested in the literature, but no confirmatory studies have been performed.

Our research is conducted at the Small Animal Clinic of the UVMB, in the dental unit. To date, plaque, saliva and blood samples from 31 cats with symptoms of TR/FORL have been taken for further laboratory tests, and the results have been compared with the data from the questionnaire filled in by the owners and findings documented during the oral examination. The Ca and P concentrations, Ca:P ratios of blood samples, and Ca:P ratios of saliva samples were measured at the Central Laboratory of the Department of Pathophysiology and Oncology of the UVMB, using an Olympus AU400 chemical analyser. For the quantitative detection PPA Lampropedia from plaque and saliva samples, qPCR was performed at the Department of Pathology of the UVMB, using a custom-designed primer, and a Quantabio Q qPCR cycler. In two cats, we also had the possibility to perform metagenomic analysis of the entire oral bacterial flora. This analysis was conducted with the Oxford Nanopore MiniON at the Small Animal Clinic of the UVMB, in collaboration with the Bioinformatics Centre of the UVMB.

A weak positive correlation was found between blood and saliva Ca:P ratios using Pearson's correlation analysis, but the correlation was not statistically significant. In our study population, both ratios were lower than those published in the literature. All samples from the oral cavity tested negative in qPCR tests for the detection of Lampropedia. Our positive control was a Lampropedia hyalina strain (ATCC43383) obtained from the American Type Culture Collection Global Bioresearch Center, and our negative controls were the two oral cavity samples that were found to be negative in metagenomic analysis. Neither qPCR nor metagenomic analysis confirmed the presence of Lampropedia in the oral cavity of the TR/FORL disease-affected cat population studied. Consequently, our hypothesis was not confirmed. Consistent with previous publications, no significant correlation was found between patient data, living conditions and the presence and stage of TR/FORL disease. Our future objective is to expand metagenomic studies and further investigate the possible role of bacterial dysbiosis in the background of TR/FORL disease.