Phylogenomic characterisation of a novel corynebacterial species pathogenic to animals

Abstract

The genus Corynebacterium includes species of biotechnological, medical and veterinary importance. An atypical C. ulcerans strain, W25, was recently isolated from a case of necrotizing lymphadenitis in a wild boar. In this study, we have analysed the genome sequence of this strain and compared the phenotypic and virulence properties with other corynebacterial pathogens. Phylogenomic analyses revealed that strain W25 belongs to a novel species along with PO100/5 and KL1196. The latter strains were isolated from a pig and a roe deer, respectively; hence, this species appears to be associated to animals. The isolate W25 is likely a nontoxigenic tox gene bearing strain and may have compromised abilities to adhere to pharyngeal and laryngeal epithelial cells due to potential loss of the gene functions in spaBC and spaDEF pilus gene clusters. A number of corynebacterial virulence genes are present including pld encoding phospholipase D. Therefore, this strain may be able to cause severe invasive infections in animals and zoonotic infections in humans.

Cellular and Extracellular Proteome of the Animal Pathogen Corynebacterium silvaticum, a Close Relative of Zoonotic Corynebacterium ulcerans and Corynebacterium pseudotuberculosis

“…From the genome sequence of C. silvaticum W25, a number of putative virulence factors was annotated [ 23 ]. In this study 12 of these were detected, while 3 were not found ( Table 1 ).…”

“…It is assumed that proteins of this family play a fundamental role in corynebacterial cell surface organization, cell separation, adhesion, and internalization in host cells [ 26 , 58 ]. C. silvaticum strain W25 produced almost all identified virulence factors [ 23 ] already under standard growth conditions except Vsp1, Cpp and NrpS1. The presence of two proteins in the extracellular environment with putative virulence potential (A0A5C5F2T7 and A0A5F0A739) needs to be further investigated.…”

“…Recently the genome sequence of the atypical C. ulcerans strain W25, isolated from a wild boar with necrotizing lymphadenitis, was published [ 21 ]. Taxonomic analyses of the genome sequence data revealed that this isolate is clustered with two different isolates previously annotated as C. ulcerans KL1196 (identical to CVUAS6455 [ 17 ]) and C. pseudotuberculosis PO100/5 [ 22 ] and clearly delineated from other published C. ulcerans strains [ 23 ]. In parallel to this study, based on biochemical properties such as carbon metabolism, antibiotic resistance pattern and lipid profile in combination with 16SrRNA gene and rpoB sequence analysis, a new species, Corynebacterium silvaticum , was described recently [ 3 ] formed from former C. ulcerans strains isolated from forest-dwelling game animals, e.g., roe deer and wild boar.…”

“…In parallel to this study, based on biochemical properties such as carbon metabolism, antibiotic resistance pattern and lipid profile in combination with 16SrRNA gene and rpoB sequence analysis, a new species, Corynebacterium silvaticum , was described recently [ 3 ] formed from former C. ulcerans strains isolated from forest-dwelling game animals, e.g., roe deer and wild boar. Strain W25, a non-toxigenic tox gene bearing (NTTB) strain [ 23 ], is obviously a member of this newly validated species.…”

Taxonomic classification of strain PO100/5 shows a broader geographic distribution and genetic markers of the recently describedCorynebacterium silvaticum

“…Genome sequencing and rpoB phylogeny showed that this strain was closer to C. ulcerans and the genome was deposited in GenBank as a strain from this species (accession number CP021417.1). During the submission and review of this manuscript, the description of C. silvaticum was published and suggested PO100/5 as a strain of this species by rpoB phylogeny [4], while a genomic analysis of 28 C. ulcerans strains suggested that PO100/5, W25 and KL1196 could represent a new species [9], although KL1196 had already been classified as C. silvaticum [4].…”