Author:
Ramos Juliana Nunes,Araújo Max Roberto Batista,Baio Paulo Victor Pereira,Sant’Anna Lincoln Oliveira,Veras João Flávio Carneiro,Vieira Érica Miranda Damásio,Sousa Mireille Ângela Bernardes,Camargo Carlos Henrique,Sacchi Cláudio Tavares,Campos Karoline Rodrigues,Santos Marlon Benedito Nascimento,Bokermann Sérgio,Alvim Luige Biciati,Sanches dos Santos Louisy,de Mattos-Guaraldi Ana Luiza,Vieira Verônica Viana
Abstract
Abstract
Background
Corynebacterium diphtheriae complex was formed by the species C. diphtheriae, Corynebacterium ulcerans and Corynebacterium pseudotuberculosis in the recent past. In addition to C. diphtheriae, C. ulcerans and C. pseudotuberculosis species can carry the tox gene, which encodes diphtheria toxin. Currently, three new species have been included in the complex: Corynebacterium rouxii, Corynebacterium silvaticum, and Corynebacterium belfantii. C. rouxii is derived from the ancient Belfanti biovar of C. diptheriae. We provide the complete genome sequences of two non-toxigenic strains C. rouxii isolated from a cat with a purulent infection in Brazil. The taxonomic status and sequence type, as well as the presence of resistance and virulence genes, and CRISPR-Cas system were additionally defined.
Results
The genomes showed an average size of 2.4 Mb and 53.2% GC content, similar to the type strain of the species deposited in Genbank/NCBI. Strains were identified as C. rouxii by the rMLST database, with 95% identity. ANI and DDH in silico were consistent with values above the proposed cut-off points for species limit, corroborating the identification of the strains as C. rouxii. MLST analyses revealed a new ST, which differs from ST-537 only by the fusA allele. No horizontal transfer resistance gene was predicted in both genomes and no mutation was detected in the constitutive genes gyrA and rpoB. Some mutations were found in the seven penicillin-binding proteins (PBPs) detected. The tox gene was not found, but its regulatory gene dtxR was present. Among the predicted virulence genes are those involved in iron uptake and adherence, in addition to the DIP0733 protein involved in epithelial cell adhesion and invasion. The CRISPR-Cas type I-E system was detected in both genomes, with 16 spacer sequences each. Of them, half are unknown according to the databases used, indicating that there is an unexplored reservoir of corynebacteriophages and plasmids.
Conclusions
This is the first genomic study of C. rouxii reported in Brazil. Here we performed taxonomic analysis and the prediction of virulence factors. The genomic analyses performed in this study may help to understand the potential pathogenesis of non-toxigenic C. rouxii strains.
Funder
Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro
Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq
Sub-Reitoria de Pós-Graduação e Pesquisa da Universidade do Estado do Rio de Janeiro
Programa Inova Fiocruz
Publisher
Springer Science and Business Media LLC
Subject
Health Informatics,Genetics