Corynebacterium rouxii sp. nov., a novel member of the diphtheriae species complex

Edgar Badell (1, 2) , Melanie Hennart (1) , Carla Rodrigues (1) , Virginie Passet (1) , Mélody Dazas (1) , Valerie Bouchez (1) , Leonardo Panunzi (1) , Annick Carmi-Leroy (1, 2) , Julie Toubiana (3, 1, 2) , Sylvain Brisse (1, 2)

1 Biodiversité et Epidémiologie des Bactéries pathogènes - Biodiversity and Epidemiology of Bacterial Pathogens
2 CNR - Centre national de Référence des Corynebactéries du Complexe Diphtheriae - National Reference Center Corynebacteria of the diphtheriae complex
3 Département de Pédiatrie et maladies infectieuses [CHU Necker]

A group of six clinical isolates previously identified as Corynebacterium diphtheriae biovar Belfanti, isolated from human cutaneous or peritoneum infections and from one dog, were characterized by genomic sequencing, biochemical analysis and MALDI-TOF mass spectrometry. The six isolates were negative for the diphtheria toxin gene. Phylogenetic analyses showed that the six isolates (including FRC0190T) are clearly demarcated from C. diphtheriae, Corynebacterium belfantii, Corynebacterium ulcerans and Corynebacterium pseudotuberculosis. The average nucleotide identity of FRC0190T with C. diphtheriae NCTC11397T was 92.6%, and was 91.8% with C. belfantii FRC0043T. C. diphtheriae subsp. lausannense strain CHUV2995T appeared to be a later heterotypic synonym of C. belfantii (ANI, 99.3%). Phenotyping data revealed an atypical negative or heterogeneous intermediate maltose fermentation reaction for the six isolates. MALDI-TOF mass spectrometry differentiated the new group from the other Corynebacterium taxa by the presence of specific spectral peaks. rpoB sequences showed identity to atypical, maltose-negative C. diphtheriae biovar Belfanti isolates previously described from two cats in the USA. We propose the name Corynebacterium rouxii sp. nov. for the novel group, with FRC0190T (= CIP 111752T = DSM 110354T) as type strain.

Keywords: MALDI-TOF; Diphtheria; Genome sequencing; diphtheria; Taxonomy; Phylogeny; genome sequencing

Domains: Life Sciences [q-bio]

Edgar Badell, Melanie Hennart, Carla Rodrigues, Virginie Passet, Mélody Dazas, et al.. Corynebacterium rouxii sp. nov., a novel member of the diphtheriae species complex. Research in Microbiology, 2020, 171 (3-4), pp.122-127. ⟨10.1016/j.resmic.2020.02.003⟩. ⟨pasteur-02862963v2⟩