Genomic analysis of two penicillin- and rifampin-resistant Corynebacterium rouxii strains isolated from cutaneous infections in dogs

Although diphtheria is a vaccine-preventable disease, numerous cases are still reported around the world, as well as outbreaks in countries, including European ones. Species of the Corynebacterium diphtheriae complex are potentially toxigenic and, therefore, must be considered given the possible consequences, such as the circulation of clones and transmission of antimicrobial resistance and virulence genes. Recently, Corynebacterium rouxii was characterized and included among the valid species of the complex. Therefore, two cases of C. rouxii infection arising from infections in domestic animals are presented here. We provide molecular characterization, phylogenetic analyses, genome sequencing, and CRISPR-Cas analyses to contribute to a better understanding of the molecular bases, pathogenesis, and epidemiological monitoring of this species, which is still little studied. We confirmed its taxonomic position with genome sequencing and in silico analysis and identified the ST-918 for both strains. The clinical isolates were sensitive resistance to benzylpenicillin and rifampin. Antimicrobial resistance genes, including tetB, rpoB2, and rbpA genes, were predicted. The bla and ampC genes were not found. Several virulence factors were also detected, including adhesion, iron uptake systems, gene regulation (dtxR), and post-translational modification (MdbA). Finally, one prophage and the Type I-E CRISPR-Cas system were identified. •We provide analyzes of the resistance genes and virulence factors of C. rouxii, reported mainly in animal infections, but also in humans.•Our data to contribute to a better understanding of the molecular bases, pathogenesis, and epidemiological monitoring of this species.•Important resistance genes were predicted, such as those related to resistance to tetracycline and rifampin.•One prophage and the Type I-E CRISPR-Cas system were identified, important data when we think about the possibility of animal-human transmission.•From the MLST analyses, we can observe that assigned ST has a common ancestor with other strains isolated in France and Brazil.