Revisão da classificação de bactérias presentes em infecções bucais utilizando ferramentas de bioinformática

Abstract

Superior do Instituto Butantan, São Paulo, 2022. Considered by the World Health Organization (WHO) a public problem that affects several countries, oral diseases affect about 3.5 billion people worldwide. There are several common oral diseases present in the population that are caused by bacteria, such as oral cavities, tartar, gingivitis and periodontitis. The mouth is the natural habitat of several bacteria, with more than 700 species known so far. Scenarios like this, characterized by a great complexity of the microbiota, demonstrate the need for accuracy in biological classification, which is essential to characterize the microorganisms present in different physiological situations, especially during pathological events. An accurate classification is also essential for the diagnosis and epidemiological monitoring of infectious diseases. Although there is a consensus that the taxonomic information of a bacterium is contained in its genome, its use for taxonomic purposes has only become more frequent with the advances in new generations of DNA sequencing technologies. In fact, for years the DNA-DNA hybridization method (DDH) was used for the classification of bacteria, however, with advances in genomics, the DDH became an outdated method, opening space for new taxonomic analysis tools, such as the average nucleotide identity (ANI), an analysis considered to be the best option for determining species boundaries and confirming the taxonomic identification of a sample. The main objective of this study was, based on genomic analyzes and the use of bioinformatics tools, to revise the classification of bacterial genera both present in the oral cavity and that contain species that cause oral infections. We chose six genera of bacteria that, according to the literature, have species that are present in oral infections. The genera chosen were: Aggregatibacter, Fusobacterium, Prevotella, Porphyromonas, Selenomonas and Veillonella. In all these genera, inconsistencies were found between the classification described in GenBank and that indicated by the ANI analysis, which allowed us to propose the reclassification of several isolates and propose the creation of new species for all these genera.