Corynebacterium capitovis sp. nov., from a sheep

Genome-Based Taxonomic Classification of the Phylum Actinobacteria

The application of phylogenetic taxonomic procedures led to improvements in the classification of bacteria assigned to the phylum Actinobacteria but even so there remains a need to further clarify relationships within a taxon that encompasses organisms of agricultural, biotechnological, clinical, and ecological importance. Classification of the morphologically diverse bacteria belonging to this large phylum based on a limited number of features has proved to be difficult, not least when taxonomic decisions rested heavily on interpretation of poorly resolved 16S rRNA gene trees. Here, draft genome sequences of a large collection of actinobacterial type strains were used to infer phylogenetic trees from genome-scale data using principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families, and genera, as well as many species and a few subspecies were shown to be in need of revision leading to proposals for the recognition of 2 orders, 10 families, and 17 genera, as well as the transfer of over 100 species to other genera. In addition, emended descriptions are given for many species mainly involving the addition of data on genome size and DNA G+C content, the former can be considered to be a valuable taxonomic marker in actinobacterial systematics. Many of the incongruities detected when the results of the present study were compared with existing classifications had been recognized from 16S rRNA gene trees though whole-genome phylogenies proved to be much better resolved. The few significant incongruities found between 16S/23S rRNA and whole genome trees underline the pitfalls inherent in phylogenies based upon single gene sequences. Similarly good congruence was found between the discontinuous distribution of phenotypic properties and taxa delineated in the phylogenetic trees though diverse non-monophyletic taxa appeared to be based on the use of plesiomorphic character states as diagnostic features.

Insight of Genus Corynebacterium: Ascertaining the Role of Pathogenic and Non-pathogenic Species

This review gathers recent information about genomic and transcriptomic studies in the Corynebacterium genus, exploring, for example, prediction of pathogenicity islands and stress response in different pathogenic and non-pathogenic species. In addition, is described several phylogeny studies to Corynebacterium, exploring since the identification of species until biological speciation in one species belonging to the genus Corynebacterium. Important concepts associated with virulence highlighting the role of Pld protein and Tox gene. The adhesion, characteristic of virulence factor, was described using the sortase mechanism that is associated to anchorage to the cell wall. In addition, survival inside the host cell and some diseases, were too addressed for pathogenic corynebacteria, while important biochemical pathways and biotechnological applications retain the focus of this review for non-pathogenic corynebacteria. Concluding, this review broadly explores characteristics in genus Corynebacterium showing to have strong relevance inside the medical, veterinary, and biotechnology field.

Non-contiguous finished genome sequence of Corynebacterium timonense type strain 5401744(T.)

Corynebacterium timonense strain 5401744^T is a member of the genus Corynebacterium which contains Gram-positive bacteria with a high G+C content. It was isolated from the blood of a patient with endocarditis. In this work, we describe a set of features of this organism, together with the complete genome sequence and annotation. The 2,553,575 bp long genome contains 2,401 protein-coding genes and 55 RNA genes, including between 5 and 6 rRNA operons.

Corynebacterium canis sp. nov., isolated from a wound infection caused by a dog bite

A non-lipophilic, coryneform bacterium isolated from a patient's wound caused by a dog bite was characterized by phenotypic, chemotaxonomic and molecular genetic methods. Chemotaxonomic features suggested assignment of the unknown bacterium to the genus Corynebacterium. The isolate exhibited the following unusual features, which made it possible to phenotypically differentiate it from all other medically relevant corynebacteria: the Gram stain showed some very filamentous rods (>15 μm in length); some cells exhibited branching; colonies were domed and adherent to agar; the micro-organism was positive for pyrazinamidase, β-glucosidase, α-glucosidase and trypsin but negative for β-galactosidase. 16S rRNA gene sequencing and partial rpoB gene sequencing showed that the closest phylogenetic relative, Corynebacterium freiburgense, exhibited more than 1.9 % and 17.9 % divergence with the unknown bacterium, respectively. Based on both phenotypic and molecular genetic data, it is proposed that the isolate should be classified as a novel species, Corynebacterium canis sp. nov., with the type strain 1170(T) (=CCUG 58627(T) =DSM 45402(T)).

Corynebacterium timonense sp. nov. and Corynebacterium massiliense sp. nov., isolated from human blood and human articular hip fluid

Gram-positive, facultatively anaerobic, rod-shaped bacteria were isolated from the blood of a patient with endocarditis (strain 5401744T) and from the hip joint fluid of a patient with an infected orthopaedic prosthesis (strain 5402485T). These strains were characterized by using a polyphasic taxonomic approach. Based on cellular morphology and biochemical criteria the two isolates were tentatively assigned to the genus Corynebacterium, although they did not correspond to any recognized species. The predominant fatty acids were a mix of C18:2omega6,9c and anteiso-C18:0 (32.1% of the total), C16:0 (26.3%) and C18:1omega9c (22.5%) for strain 5402485T and C18:1omega9c (36.4%), C17:1omega9c (27.1%) and C16:0 (10.9%) for strain 5401744T. Phylogenetic analysis based on 16S rRNA gene sequence comparisons showed that strain 5401744T was closely related to the type strains of Corynebacterium auris, Corynebacterium capitovis, Corynebacterium lipophiloflavum and Corynebacterium mycetoides (97.0, 96.6, 96.5 and 96.3% similarity, respectively) and strain 5402485T was closely related to the type strains of Corynebacterium macginleyi, Corynebacterium accolens, Corynebacterium tuberculostearicum, Corynebacterium confusum, Corynebacterium mastitidis and Corynebacterium renale (95.6, 95.3, 95.3, 94.5, 94.0 and 93.5%, respectively). On the basis of phenotypic data and phylogenetic inference, these isolates are considered to represent two novel species of the genus Corynebacterium, for which the names Corynebacterium timonense sp. nov. (type strain, 5401744T=CSUR P20T=CIP 109424T=CCUG 53856T) and Corynebacterium massiliense sp. nov. (type strain, 5402485T=CSUR P19T=CIP 109423T=CCUG 53857T) are proposed.

Corynebacterium ureicelerivorans sp. nov., a lipophilic bacterium isolated from blood culture

A lipophilic coryneform bacterium isolated from a blood culture from a patient with signs of septicaemia was characterized by means of phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV and short-chain mycolic acids, which are consistent with the genus Corynebacterium. The isolate was characterized biochemically by the very rapid (approx. 60 s) positive result that was obtained in a urease test in the API Coryne system. Comparative 16S rRNA gene sequencing demonstrated that the isolate belonged phylogenetically to the genus Corynebacterium. The values for sequence divergence (⩾1.4 %) with respect to known Corynebacterium species, together with phenotypic differences, show that the unidentified bacterium represents a novel member of this genus. On the basis of both the phenotypic and phylogenetic data, this isolate should be classified within a novel species of the genus Corynebacterium, for which the name Corynebacterium ureicelerivorans sp. nov. is proposed. The type strain is IMMIB RIV-2301T (=DSM 45051T=CCUG 53377T).

Corynebacterium ciconiae sp. nov., isolated from the trachea of black storks (Ciconia nigra)

Eight unidentified Gram-positive, rod-shaped organisms were recovered from the tracheas of apparently healthy black storks (Ciconia nigra) and subjected to a polyphasic taxonomic analysis. Based on cellular morphology and biochemical criteria the isolates were tentatively assigned to the genus Corynebacterium, although three of the organisms did not appear to correspond to any recognized species. Comparative 16S rRNA gene sequencing studies demonstrated that all of the isolates were phylogenetically members of the genus Corynebacterium. Five strains were genotypically identified as representing Corynebacterium falsenii, whereas the remaining three strains represented a hitherto unknown subline, associated with a small subcluster of species that includes Corynebacterium mastitidis and its close relatives. On the basis of phenotypic and phylogenetic evidence, it is proposed that the unknown isolates from black storks represent a novel species within the genus Corynebacterium, for which the Corynebacterium ciconiae sp. nov. is proposed. The type strain is CECT 5779T (=BS13T=CCUG 47525T).

Taxonomic characterization of nine strains isolated from clinical and environmental specimens, and proposal of Corynebacterium tuberculostearicum sp. nov

Nine unidentified Gram-positive, lipophilic corynebacteria were isolated from clinical and food samples and subjected to a polyphasic taxonomic analysis. The bacteria were distinguished from Corynebacterium species with validly published names by biochemical tests, fatty acid content and whole-cell protein analysis. Comparative 16S rRNA gene sequence analysis demonstrated unambiguously that the nine strains were related phylogenetically to the species ‘Corynebacterium tuberculostearicum’ and represented a distinct subline within the genus Corynebacterium. On the basis of both phenotypic and phylogenetic evidence, the formal description of Corynebacterium tuberculostearicum sp. nov. is proposed. The type strain of C. tuberculostearicum is Medalle XT (=LDC-20T=CIP 107291T=CCUG 45418T=ATCC 35529T).

Corynebacterium caspium sp. nov., from a Caspian seal (Phoca caspica)

A previously unknown Gram-positive, non-spore-forming, non-lipophilic, catalase-positive, irregular rod-shaped bacterium (M/106/00/5T) was isolated, in mixed culture, from the penis of a Caspian seal (Phoca caspica). The strain was a facultative anaerobe that was able to grow at 22 and 42 °C. Comparative 16S rRNA gene sequencing showed that the organism formed a hitherto unknown subline within the genus Corynebacterium. Sequence divergence values of more than 5 % from other described Corynebacterium species, together with phenotypic differences, showed that the unidentified bacterium represents a previously unrecognized member of this genus. On the basis of phenotypic and phylogenetic considerations, it is proposed that the unknown bacterium isolated from a Caspian seal (strain M/106/00/5T=CCUG 44566T=CIP 107965T) be classified as the type strain of a novel species of the genus Corynebacterium, Corynebacterium caspium sp. nov.

Isolation of Corynebacterium falsenii and description of Corynebacterium aquilae sp. nov., from eagles

Biochemical, molecular chemical and molecular genetic studies were performed on seven unidentified gram-positive, rod-shaped organisms recovered from eagles. The strains were provisionally identified as Corynebacterium jeikeium with the commercial API Coryne system, but they were able to grow under anaerobic conditions and were non-lipophilic. Comparative 16S rRNA gene sequencing studies demonstrated that the isolates belonged phylogenetically to the genus Corynebacterium. Three strains were identified genotypically as Corynebacterium falsenii; the remaining four strains corresponded to a hitherto unknown lineage within the genus Corynebacterium, associated with a small subcluster of species that included Corynebacterium diphtheriae and its close relatives. The unknown bacterial strains were readily distinguished from these and other species of the genus by biochemical tests. Based on both phenotypic and phylogenetic evidence, it is proposed that the unknown bacterial strains from eagles should be classified as Corynebacterium aquilae sp. nov. (type strain is S-613T = CECT 5993T = CCUG 46511T).

Corynebacterium sphenisci sp. nov., isolated from wild penguins

Six unidentified gram-positive, rod-shaped organisms recovered from the cloacae of apparently healthy wild penguins were characterized by phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of a cell wall based on meso-diaminopimelic acid and long-chain cellular fatty acids of the straight-chain saturated and monounsaturated types, consistent with the genus Corynebacterium. Corynomycolic acids, which are characteristic of the genus, were also detected, albeit in small amounts. Comparative 16S rRNA gene sequencing studies showed that the unidentified organisms were phylogenetically related to corynebacteria and represent a novel subline associated with a small subcluster of species that includes Corynebacterium xerosis, Corynebacterium amycolatum and Corynebacterium freneyi. The unknown isolates were readily distinguished from their closest phylogenetic relatives and all other Corynebacterium species with validly published names by using a combination of biochemical and chemotaxonomic criteria. Based on both phenotypic and 16S rRNA gene sequence considerations, it is proposed that the unknown isolates recovered from penguins be classified as a novel species in the genus Corynebacterium, Corynebacterium sphenisci sp. nov. The type strain is CECT 5990T (= CCUG 46398T).

Corynebacterium spheniscorum sp. nov., isolated from the cloacae of wild penguins

Twenty unidentified Gram-positive, rod-shaped organisms were recovered from the cloacae of apparently healthy wild penguins (Spheniscus magellanicus) and subjected to a polyphasic taxonomic analysis. On the basis of cellular morphology and biochemical criteria, the isolates were tentatively assigned to the genus Corynebacterium, although the organisms did not appear to correspond to any recognized species. Lipid studies confirmed this generic placement, and comparative 16S rRNA gene sequencing showed that the unidentified organisms represent a hitherto unknown subline, associated with a small subcluster of species that includes Corynebacterium diphtheriae and its close relatives. On the basis of phenotypic and phylogenetic evidence, it is proposed that the unknown isolates from penguins be classified in the genus Corynebacterium, as Corynebacterium spheniscorum sp. nov. The type strain is strain PG 39T (=CCUG 45512T =CECT 5986T).