Corynebacterium silvaticum sp. nov., a unique group of NTTB corynebacteria in wild boar and roe deer

Abstract

<jats:p>A total of 34 <jats:italic> <jats:named-content content-type="genus"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.6188" xlink:type="simple">Corynebacterium</jats:ext-link> </jats:named-content> </jats:italic> sp. strains were isolated from caseous lymph node abscesses of wild boar and roe deer in different regions of Germany. They showed slow growth on Columbia sheep blood agar and sparse growth on Hoyle’s tellurite agar. Cellular fatty acid analysis allocated them in the <jats:italic> <jats:named-content content-type="species"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.6189" xlink:type="simple">C. diphtheriae</jats:ext-link> </jats:named-content> </jats:italic> group of genus <jats:italic> <jats:named-content content-type="genus"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.6188" xlink:type="simple">Corynebacterium</jats:ext-link> </jats:named-content> </jats:italic>. MALDI-TOF MS using specific database extensions and <jats:italic>rpoB</jats:italic> sequencing resulted in classification as <jats:italic> <jats:named-content content-type="species"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.6276" xlink:type="simple">C. ulcerans</jats:ext-link> </jats:named-content> </jats:italic>. Their quinone system is similar to <jats:italic> <jats:named-content content-type="species"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.6276" xlink:type="simple">C. ulcerans</jats:ext-link> </jats:named-content> </jats:italic>, with major menaquinone MK-8(H2). Their complex polar lipid profile includes major lipids phosphatidylinositol, phosphatidylinositol-mannoside, diphosphatidylglycerol, but also unidentified glycolipids, distinguishing them clearly from <jats:italic> <jats:named-content content-type="species"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.6276" xlink:type="simple">C. ulcerans</jats:ext-link> </jats:named-content> </jats:italic>. They ferment glucose, ribose and maltose (like <jats:italic> <jats:named-content content-type="species"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.6276" xlink:type="simple">C. ulcerans</jats:ext-link> </jats:named-content> </jats:italic>), but do not utilise <jats:sc>d</jats:sc>-xylose, mannitol, lactose, sucrose and glycogen (like <jats:italic> <jats:named-content content-type="species"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.6258" xlink:type="simple">C. pseudotuberculosis</jats:ext-link> </jats:named-content> </jats:italic>). They showed activity of catalase, urease and phospholipase D, but variable results for alkaline phosphatase and alpha-glucosidase. All were non-toxigenic, <jats:italic>tox</jats:italic> gene bearing and susceptible to clindamycin, penicillin and erythromycin. In 16SrRNA gene and RpoB protein phylogenies the strains formed distinct brancheswith <jats:italic> <jats:named-content content-type="species"> <jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="uri" xlink:href="http://doi.org/10.1601/nm.6276" xlink:type="simple">C. ulcerans</jats:ext-link> </jats:named-content> </jats:italic> as nearest relative.Whole genome sequencing revealed the unique sequence type 578, a distinctbranch in pangenomic core genome MLST, average nucleotide identities &lt;91%, enhancedgenome sizes (2.55 Mbp) and G/C content (54.4 mol%) compared to related species.These results suggest that the strains represent a novel species, for which wepropose the name <jats:italic>Corynebactriumsilvaticum</jats:italic> sp. nov., based on their first isolation from forest-dwellinggame animals. The type strain isKL0182<jats:sup>T</jats:sup> (= CVUAS 4292<jats:sup>T</jats:sup> = DSM 109166<jats:sup>T</jats:sup> = LMG 31313<jats:sup>T</jats:sup>= CIP 111 672<jats:sup>T</jats:sup>).</jats:p>

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

“…The genus Corynebacterium , first described in 1886 as a group of Gram-positive, club- (greek: korune ) or rod-shaped bacteria [ 1 ], comprises between 142 and 145 different species today [ 2 , 3 ]. These were often isolated from human or animal material and are frequently of medical or veterinary importance [ 4 , 5 ].…”

“…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. 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

“…In this group, three new species were recently described. C. belfantii is a reclassification of C. diphtheriae biovar Belfanti [2] and a synonym of C. diphtheriae subspecies lausannense [3], C. rouxii [3] is reclassifications of C. diphtheriae biovar Belfanti, and C. silvaticum [4] is a reclassification of atypical C. ulcerans strains. Strains of C. silvaticum were previously described as atypical non-toxigenic but tox -gene-bearing (NTTB) strains of C. ulcerans , isolated from wild boars and roe deer in Germany, which caused caseous lymphadenitis similar to C. pseudotuberculosis infections [5–7].…”

“…Strains of C. silvaticum were previously described as atypical non-toxigenic but tox -gene-bearing (NTTB) strains of C. ulcerans , isolated from wild boars and roe deer in Germany, which caused caseous lymphadenitis similar to C. pseudotuberculosis infections [5–7]. This variant, examined using genomics and proteomics, was initially named as a “wild boar cluster” (WBC) of C. ulcerans [5–7] and later reclassified as C. silvaticum [4].…”

“…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].…”