Investigando a taxonomia de Enterococcus casseliflavus e espécies relacionadas

Abstract

Enterococcus casseliflavus, a commonly motile, yellow-colored bacterium, is a commensal member of the gastrointestinal tract of vertebrates and invertebrates. It is occasionally found in cases of bacteremia and other human infections. One concern is that all strains of this species have the vanC gene cluster on their chromosome, which confers resistance to vancomycin. The classification of E. casseliflavus is complex, as it presents 99% identity in the 16S analysis with E. gallinarum and, mainly, with E. flavescens, being often classified as a single species. In the view of this problem, the goal of this study was to investigate the taxonomy of E. casseliflavus and other related species by analyzing genomic data available in public databases. For this purpose, 155 genomes of species related to E. casseliflavus (E. casseliflavus, E. flavescens, E. entomosocium and E. innesii) were rescued and subjected to Average Nucleotide Identity (ANI), pangenome and phylogenomic analysis. The approaches showed three well-defined groups corresponding to three species of Enterococcus (E. casseliflavus, E. flavescens and E. innesii). With characteristics of an open pangenome, the group showed great conservation of core genes and high accessory genome diversity. Here we suggest removing the synonymous species status between the species E. flavescens and E. casseliflavus and adding the synonymous species status between E. entomosocium and E. casseliflavus.