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63-433: See text. Corynebacterium ( / k ɔː ˈ r aɪ n ə b æ k ˌ t ɪər i ə m , - ˈ r ɪ n -/ ) is a genus of Gram-positive bacteria and most are aerobic . They are bacilli (rod-shaped), and in some phases of life they are, more specifically, club -shaped, which inspired the genus name ( coryneform means "club-shaped"). They are widely distributed in nature in the microbiota of animals (including

126-465: A buildup of intermediates occurs, so scientists have developed mutant strains of C. glutamicum through PCR engineering and chemical knockouts to ensure production of side-reaction enzymes are limited. Many genetic manipulations conducted in industry are by traditional cross-over methods or inhibition of transcriptional activators. Expression of functionally active human epidermal growth factor has been brought about in C. glutamicum , thus demonstrating

189-802: A characteristic way, which has been described as the form of a "V", "palisades", or "Chinese characters". They may also appear elliptical . They are aerobic or facultatively anaerobic , chemoorganotrophs . They are pleomorphic through their lifecycles , they occur in various lengths, and they frequently have thickenings at either end, depending on the surrounding conditions. Some corynebacteria are lipophilic (such as CDC coryneform groups F-1 and G, C. accolens , C. afermentans subsp. lipophilum , C. bovis , C. jeikeium , C. macginleyi , C. uropygiale , and C. urealyticum ), but medically relevant corynebacteria are typically not. The nonlipophilic bacteria may be classified as fermentative (such as C. amycolatum ; C. argentoratense , members of

252-694: A complex commonly seen in Corynebacterium species: the mycolyl-AG–peptidoglican (mAGP). Unlike most corynebacteria, Corynebacterium kroppenstedtii does not contain mycolic acids. Corynebacteria grow slowly, even on enriched media. In nutritional requirements, all need biotin to grow. Some strains also need thiamine and PABA . Some of the Corynebacterium species with sequenced genomes have between 2.5 and 3.0 million base pairs. The bacteria grow in Loeffler's medium , blood agar , and trypticase soy agar (TSA). They form small, grayish colonies with

315-476: A conserved region of the enzyme phosphoribose diphosphate:decaprenyl-phosphate phosphoribosyltransferase and a three-amino-acid insertion in acetate kinase , both of which are found only in Corynebacterium species. Both of these indels serve as molecular markers for species of the genus Corynebacterium . Additionally, 16 conserved signature proteins, which are uniquely found in Corynebacterium species, have been identified. Three of these have homologs found in

378-407: A genus is determined by taxonomists . The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: Moreover, genera should be composed of phylogenetic units of

441-583: A granular appearance, mostly translucent, but with opaque centers, convex, with continuous borders. The color tends to be yellowish-white in Loeffler's medium. In TSA, they can form grey colonies with black centers and dentated borders that either resemble flowers ( C. gravis ), continuous borders ( C. mitis ), or a mix between the two forms ( C. intermedium ). Corynebacterium species occur commonly in nature in soil, water, plants, and food products. The non-diphtheroid Corynebacterium species can even be found in

504-496: A high G+C content ranging from 46-74 mol%. The principal features of the genus Corynebacterium were described by Collins and Cummins, for Coryn Taylor in 1986. They are gram-positive, catalase -positive, non- spore -forming, non- motile , rod-shaped bacteria that are straight or slightly curved. Metachromatic granules are usually present representing stored phosphate regions. Their size falls between 2 and 6 μm in length and 0.5 μm in diameter. The bacteria group together in

567-651: A later homonym of a validly published name is a nomen illegitimum or nom. illeg. ; for a full list refer to the International Code of Nomenclature for algae, fungi, and plants and the work cited above by Hawksworth, 2010. In place of the "valid taxon" in zoology, the nearest equivalent in botany is " correct name " or "current name" which can, again, differ or change with alternative taxonomic treatments or new information that results in previously accepted genera being combined or split. Prokaryote and virus codes of nomenclature also exist which serve as

630-628: A long time and redescribed as new by a range of subsequent workers, or if a range of genera previously considered separate taxa have subsequently been consolidated into one. For example, the World Register of Marine Species presently lists 8 genus-level synonyms for the sperm whale genus Physeter Linnaeus, 1758, and 13 for the bivalve genus Pecten O.F. Müller, 1776. Within the same kingdom, one generic name can apply to one genus only. However, many names have been assigned (usually unintentionally) to two or more different genera. For example,

693-432: A mean of 41%. The GC-content of Yeast ( Saccharomyces cerevisiae ) is 38%, and that of another common model organism , thale cress ( Arabidopsis thaliana ), is 36%. Because of the nature of the genetic code , it is virtually impossible for an organism to have a genome with a GC-content approaching either 0% or 100%. However, a species with an extremely low GC-content is Plasmodium falciparum (GC% = ~20%), and it

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756-449: A potential for industrial-scale production of human proteins. Expressed proteins can be targeted for secretion through either the general secretory pathway or the twin-arginine translocation pathway . Unlike gram-negative bacteria, the gram-positive Corynebacterium species lack lipopolysaccharides that function as antigenic endotoxins in humans. Corynebacterium comprises the following species: Genus The composition of

819-409: A reference for designating currently accepted genus names as opposed to others which may be either reduced to synonymy, or, in the case of prokaryotes, relegated to a status of "names without standing in prokaryotic nomenclature". An available (zoological) or validly published (botanical) name that has been historically applied to a genus but is not regarded as the accepted (current/valid) name for

882-515: A synthetic oligonucleotide such as a primer . Qualitatively, guanine (G) and cytosine (C) undergo a specific hydrogen bonding with each other, whereas adenine (A) bonds specifically with thymine (T) in DNA and with uracil (U) in RNA. Quantitatively, each GC base pair is held together by three hydrogen bonds, while AT and AU base pairs are held together by two hydrogen bonds. To emphasize this difference,

945-427: A taxon; however, the names published in suppressed works are made unavailable via the relevant Opinion dealing with the work in question. In botany, similar concepts exist but with different labels. The botanical equivalent of zoology's "available name" is a validly published name . An invalidly published name is a nomen invalidum or nom. inval. ; a rejected name is a nomen rejiciendum or nom. rej. ;

1008-455: A total of c. 520,000 published names (including synonyms) as at end 2019, increasing at some 2,500 published generic names per year. "Official" registers of taxon names at all ranks, including genera, exist for a few groups only such as viruses and prokaryotes, while for others there are compendia with no "official" standing such as Index Fungorum for fungi, Index Nominum Algarum and AlgaeBase for algae, Index Nominum Genericorum and

1071-612: Is discouraged by both the International Code of Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants , there are some five thousand such names in use in more than one kingdom. For instance, A list of generic homonyms (with their authorities), including both available (validly published) and selected unavailable names, has been compiled by the Interim Register of Marine and Nonmarine Genera (IRMNG). The type genus forms

1134-554: Is distinguished by several conserved signature indels, such as a two-amino-acid insertion in LepA and a seven- or eight-amino-acid insertions in RpoC. Also, 21 conserved signature proteins are found only in members of cluster I. Another cluster has been proposed, consisting of C. jeikeium and C. urealyticum , which is supported by the presence of 19 distinct conserved signature proteins which are unique to these two species. Corynebacteria have

1197-449: Is more common in developing countries It can occasionally infect wounds, the vulva , the conjunctiva , and the middle ear . It can be spread within a hospital . The virulent and toxigenic strains produce an exotoxin formed by two polypeptide chains, which is itself produced when a bacterium is transformed by a gene from the β prophage . Several species cause disease in animals, most notably C. pseudotuberculosis , which causes

1260-460: Is somewhat arbitrary. Although all species within a genus are supposed to be "similar", there are no objective criteria for grouping species into genera. There is much debate among zoologists about whether enormous, species-rich genera should be maintained, as it is extremely difficult to come up with identification keys or even character sets that distinguish all species. Hence, many taxonomists argue in favor of breaking down large genera. For instance,

1323-547: Is specific to C. glutamicum in which core metabolic enzymes are manipulated through genetic engineering to drive metabolic flux towards the production of NADPH from the pentose phosphate pathway, and L-4-aspartyl phosphate, the commitment step to the synthesis of L-lysine, lysC , dapA, dapC, and dapF. These enzymes are up-regulated in industry through genetic engineering to ensure adequate amounts of lysine precursors are produced to increase metabolic flux. Unwanted side reactions such as threonine and asparagine production can occur if

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1386-474: Is the type species , and the generic name is permanently associated with the type specimen of its type species. Should the specimen turn out to be assignable to another genus, the generic name linked to it becomes a junior synonym and the remaining taxa in the former genus need to be reassessed. In zoological usage, taxonomic names, including those of genera, are classified as "available" or "unavailable". Available names are those published in accordance with

1449-414: Is used to represent corynebacteria that are non pathogenic ; for example, C. diphtheriae would be excluded. The term diphtheroid comes from Greek διφθέρα, diphthérā 'prepared hide, leather'. Comparative analysis of corynebacterial genomes has led to the identification of several conserved signature indels (CSIs) that are unique to the genus. Two examples of CSIs are a two-amino-acid insertion in

1512-477: Is usually common to refer to such examples as being AT-rich instead of GC-poor. Several mammalian species (e.g., shrew , microbat , tenrec , rabbit ) have independently undergone a marked increase in the GC-content of their genes. These GC-content changes are correlated with species life-history traits (e.g., body mass or longevity) and genome size , and might be linked to a molecular phenomenon called

1575-601: The C. diphtheriae group, C. glucuronolyticum , C. glutamicum , C. matruchotii , C. minutissimum , C. striatum , and C. xerosis ) or nonfermentative (such as C. afermentans subsp. afermentans , C. auris , C. pseudodiphtheriticum , and C. propinquum ). The cell wall is distinctive, with a predominance of mesodiaminopimelic acid in the murein wall and many repetitions of arabinogalactan , as well as corynemycolic acid (a mycolic acid with 22 to 26 carbon atoms), bound by disaccharide bonds called L-Rha p -(1 → 4)--D-GlcNAc-phosphate. These form

1638-621: The International Code of Zoological Nomenclature ; the earliest such name for any taxon (for example, a genus) should then be selected as the " valid " (i.e., current or accepted) name for the taxon in question. Consequently, there will be more available names than valid names at any point in time; which names are currently in use depending on the judgement of taxonomists in either combining taxa described under multiple names, or splitting taxa which may bring available names previously treated as synonyms back into use. "Unavailable" names in zoology comprise names that either were not published according to

1701-824: The International Plant Names Index for plants in general, and ferns through angiosperms, respectively, and Nomenclator Zoologicus and the Index to Organism Names for zoological names. Totals for both "all names" and estimates for "accepted names" as held in the Interim Register of Marine and Nonmarine Genera (IRMNG) are broken down further in the publication by Rees et al., 2020 cited above. The accepted names estimates are as follows, broken down by kingdom: The cited ranges of uncertainty arise because IRMNG lists "uncertain" names (not researched therein) in addition to known "accepted" names;

1764-612: The human microbiota ) and are mostly innocuous, most commonly existing in commensal relationships with their hosts. Some, such as C. glutamicum , are commercially and industrially useful. Others can cause human disease, including, most notably, diphtheria , which is caused by C. diphtheriae . Like various species of microbiota (including their relatives in the genera Arcanobacterium and Trueperella ), they usually are not pathogenic , but can occasionally opportunistically capitalize on atypical access to tissues (via wounds ) or weakened host defenses . The genus Corynebacterium

1827-742: The mucosa and normal skin flora of humans and animals. Unusual habitats, such as the preen gland of birds , have been recently reported for Corynebacterium uropygiale . Some species are known for their pathogenic effects in humans and other animals. Perhaps the most notable one is C. diphtheriae , which acquires the capacity to produce diphtheria toxin only after interacting with a bacteriophage . Other pathogenic species in humans include: C. amycolatum , C. striatum , C. jeikeium , C. urealyticum , and C. xerosis ; all of these are important as pathogens in immunosuppressed patients. Pathogenic species in other animals include C. bovis and C. renale . This genus has been found to be part of

1890-419: The nomenclature codes , which allow each species a single unique name that, for animals (including protists ), plants (also including algae and fungi ) and prokaryotes ( bacteria and archaea ), is Latin and binomial in form; this contrasts with common or vernacular names , which are non-standardized, can be non-unique, and typically also vary by country and language of usage. Except for viruses ,

1953-404: The platypus belongs to the genus Ornithorhynchus although George Shaw named it Platypus in 1799 (these two names are thus synonyms ) . However, the name Platypus had already been given to a group of ambrosia beetles by Johann Friedrich Wilhelm Herbst in 1793. A name that means two different things is a homonym . Since beetles and platypuses are both members of the kingdom Animalia,

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2016-399: The third-codon position GC content, with a range from less than 30% to more than 80%. GC content is found to be variable with different organisms, the process of which is envisaged to be contributed to by variation in selection , mutational bias, and biased recombination-associated DNA repair . The average GC-content in human genomes ranges from 35% to 60% across 100-Kb fragments, with

2079-526: The DNA or RNA molecule under investigation has been reliably sequenced , then GC-content can be accurately calculated by simple arithmetic or by using a variety of publicly available software tools, such as the free online GC calculator . The GC-ratio within a genome is found to be markedly variable. These variations in GC-ratio within the genomes of more complex organisms result in a mosaic-like formation with islet regions called isochores . This results in

2142-504: The GC base pairs, making high-GC-content RNA structures more resistant to the effects of high temperatures. More recently, it has been demonstrated that the most important factor contributing to the thermal stability of double-stranded nucleic acids is actually due to the base stackings of adjacent bases rather than the number of hydrogen bonds between the bases. There is more favorable stacking energy for GC pairs than for AT or AU pairs because of

2205-524: The GC-biased gene conversion . In polymerase chain reaction (PCR) experiments, the GC-content of short oligonucleotides known as primers is often used to predict their annealing temperature to the template DNA. A higher GC-content level indicates a relatively higher melting temperature. Many sequencing technologies, such as Illumina sequencing , have trouble reading high-GC-content sequences. Bird genomes are known to have many such parts, causing

2268-442: The base for higher taxonomic ranks, such as the family name Canidae ("Canids") based on Canis . However, this does not typically ascend more than one or two levels: the order to which dogs and wolves belong is Carnivora ("Carnivores"). The numbers of either accepted, or all published genus names is not known precisely; Rees et al., 2020 estimate that approximately 310,000 accepted names (valid taxa) may exist, out of

2331-560: The base pairings are often represented as "G≡C" versus "A=T" or "A=U". DNA with low GC-content is less stable than DNA with high GC-content; however, the hydrogen bonds themselves do not have a particularly significant impact on molecular stability, which is instead caused mainly by molecular interactions of base stacking. In spite of the higher thermostability conferred to a nucleic acid with high GC-content, it has been observed that at least some species of bacteria with DNA of high GC-content undergo autolysis more readily, thereby reducing

2394-637: The disease caseous lymphadenitis , and some are also pathogenic in humans. Some attack healthy hosts , while others tend to attack the immunocompromised . Effects of infection include granulomatous lymphadenopathy , pneumonitis , pharyngitis , skin infections, and endocarditis . Corynebacterial endocarditis is seen most frequently in patients with intravascular devices. Several species of Corynebacterium can cause trichomycosis axillaris . C. striatum may cause axillary odor. C. minutissimum causes erythrasma . Nonpathogenic species of Corynebacterium are used for important industrial applications, such as

2457-447: The entire genome. There is evidence that the length of the coding region of a gene is directly proportional to higher G+C content. This has been pointed to the fact that the stop codon has a bias towards A and T nucleotides, and, thus, the shorter the sequence the higher the AT bias. Comparison of more than 1,000 orthologous genes in mammals showed marked within-genome variations of

2520-446: The form "author, year" in zoology, and "standard abbreviated author name" in botany. Thus in the examples above, the genus Canis would be cited in full as " Canis Linnaeus, 1758" (zoological usage), while Hibiscus , also first established by Linnaeus but in 1753, is simply " Hibiscus L." (botanical usage). Each genus should have a designated type , although in practice there is a backlog of older names without one. In zoology, this

2583-737: The generic name (or its abbreviated form) still forms the leading portion of the scientific name, for example, Canis lupus lupus for the Eurasian wolf subspecies, or as a botanical example, Hibiscus arnottianus ssp. immaculatus . Also, as visible in the above examples, the Latinised portions of the scientific names of genera and their included species (and infraspecies, where applicable) are, by convention, written in italics . The scientific names of virus species are descriptive, not binomial in form, and may or may not incorporate an indication of their containing genus; for example,

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2646-425: The genus Dietzia , which is believed to be the closest related genus to Corynebacterium . In phylogenetic trees based on concatenated protein sequences or 16S rRNA, the genus Corynebacterium forms a distinct clade, within which is a distinct subclade, cluster I. The cluster is made up of the species C. diphtheriae, C. pseudotuberculosis, C. ulcerans, C. aurimucosum, C. glutamicum, and C. efficiens . This cluster

2709-612: The human salivary microbiome . The most notable human infection is diphtheria , caused by C. diphtheriae . It is an acute, contagious infection characterized by pseudomembranes of dead epithelial cells , white blood cells , red blood cells , and fibrin that form around the tonsils and back of the throat . In developed countries, it is an uncommon illness that tends to occur in un vaccinated individuals, especially school-aged children, elderly , neutropenic or immunocompromised patients, and those with prosthetic devices such as prosthetic heart valves , shunts , or catheters . It

2772-633: The largest component, with 23,236 ± 5,379 accepted genus names, of which 20,845 ± 4,494 are angiosperms (superclass Angiospermae). By comparison, the 2018 annual edition of the Catalogue of Life (estimated >90% complete, for extant species in the main) contains currently 175,363 "accepted" genus names for 1,744,204 living and 59,284 extinct species, also including genus names only (no species) for some groups. The number of species in genera varies considerably among taxonomic groups. For instance, among (non-avian) reptiles , which have about 1180 genera,

2835-416: The lizard genus Anolis has been suggested to be broken down into 8 or so different genera which would bring its ~400 species to smaller, more manageable subsets. GC content In molecular biology and genetics , GC-content (or guanine-cytosine content ) is the percentage of nitrogenous bases in a DNA or RNA molecule that are either guanine (G) or cytosine (C). This measure indicates

2898-498: The longevity of the cell per se . Because of the thermostability of GC pairs, it was once presumed that high GC-content was a necessary adaptation to high temperatures, but this hypothesis was refuted in 2001. Even so, it has been shown that there is a strong correlation between the optimal growth of prokaryotes at higher temperatures and the GC-content of structural RNAs such as ribosomal RNA , transfer RNA , and many other non-coding RNAs . The AU base pairs are less stable than

2961-403: The most (>300) have only 1 species, ~360 have between 2 and 4 species, 260 have 5–10 species, ~200 have 11–50 species, and only 27 genera have more than 50 species. However, some insect genera such as the bee genera Lasioglossum and Andrena have over 1000 species each. The largest flowering plant genus, Astragalus , contains over 3,000 species. Which species are assigned to a genus

3024-428: The name could not be used for both. Johann Friedrich Blumenbach published the replacement name Ornithorhynchus in 1800. However, a genus in one kingdom is allowed to bear a scientific name that is in use as a generic name (or the name of a taxon in another rank) in a kingdom that is governed by a different nomenclature code. Names with the same form but applying to different taxa are called "homonyms". Although this

3087-430: The problem of "missing genes" expected to be present from evolution and phenotype but never sequenced — until improved methods were used. The species problem in non-eukaryotic taxonomy has led to various suggestions in classifying bacteria, and the ad hoc committee on reconciliation of approaches to bacterial systematics of 1987 has recommended use of GC-ratios in higher-level hierarchical classification. For example,

3150-443: The production of amino acids and nucleotides , bioconversion of steroids , degradation of hydrocarbons , cheese aging, and production of enzymes . Some species produce metabolites similar to antibiotics : bacteriocins of the corynecin-linocin type, antitumor agents, etc. One of the most studied species is C. glutamicum , whose name refers to its capacity to produce glutamic acid in aerobic conditions. L-Lysine production

3213-411: The proportion of G and C bases out of an implied four total bases, also including adenine and thymine in DNA and adenine and uracil in RNA. GC-content may be given for a certain fragment of DNA or RNA or for an entire genome . When it refers to a fragment, it may denote the GC-content of an individual gene or section of a gene (domain), a group of genes or gene clusters, a non-coding region , or

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3276-541: The provisions of the ICZN Code, e.g., incorrect original or subsequent spellings, names published only in a thesis, and generic names published after 1930 with no type species indicated. According to "Glossary" section of the zoological Code, suppressed names (per published "Opinions" of the International Commission of Zoological Nomenclature) remain available but cannot be used as the valid name for

3339-528: The relative positions of exocyclic groups. Additionally, there is a correlation between the order in which the bases stack and the thermal stability of the molecule as a whole. GC-content is usually expressed as a percentage value, but sometimes as a ratio (called G+C ratio or GC-ratio ). GC-content percentage is calculated as whereas the AT/GC ratio is calculated as The GC-content percentages as well as GC-ratio can be measured by several means, but one of

3402-470: The same kind as other (analogous) genera. The term "genus" comes from Latin genus , a noun form cognate with gignere ('to bear; to give birth to'). The Swedish taxonomist Carl Linnaeus popularized its use in his 1753 Species Plantarum , but the French botanist Joseph Pitton de Tournefort (1656–1708) is considered "the founder of the modern concept of genera". The scientific name (or

3465-408: The scientific epithet) of a genus is also called the generic name ; in modern style guides and science, it is always capitalised. It plays a fundamental role in binomial nomenclature , the system of naming organisms , where it is combined with the scientific name of a species : see Botanical name and Specific name (zoology) . The rules for the scientific names of organisms are laid down in

3528-433: The simplest methods is to measure the melting temperature of the DNA double helix using spectrophotometry . The absorbance of DNA at a wavelength of 260 nm increases fairly sharply when the double-stranded DNA molecule separates into two single strands when sufficiently heated. The most commonly used protocol for determining GC-ratios uses flow cytometry for large numbers of samples. In an alternative manner, if

3591-497: The specific name particular to the wolf. A botanical example would be Hibiscus arnottianus , a particular species of the genus Hibiscus native to Hawaii. The specific name is written in lower-case and may be followed by subspecies names in zoology or a variety of infraspecific names in botany . When the generic name is already known from context, it may be shortened to its initial letter, for example, C. lupus in place of Canis lupus . Where species are further subdivided,

3654-412: The standard format for a species name comprises the generic name, indicating the genus to which the species belongs, followed by the specific epithet, which (within that genus) is unique to the species. For example, the gray wolf 's scientific name is Canis lupus , with Canis ( Latin for 'dog') being the generic name shared by the wolf's close relatives and lupus (Latin for 'wolf') being

3717-403: The taxon is termed a synonym ; some authors also include unavailable names in lists of synonyms as well as available names, such as misspellings, names previously published without fulfilling all of the requirements of the relevant nomenclatural code, and rejected or suppressed names. A particular genus name may have zero to many synonyms, the latter case generally if the genus has been known for

3780-576: The values quoted are the mean of "accepted" names alone (all "uncertain" names treated as unaccepted) and "accepted + uncertain" names (all "uncertain" names treated as accepted), with the associated range of uncertainty indicating these two extremes. Within Animalia, the largest phylum is Arthropoda , with 151,697 ± 33,160 accepted genus names, of which 114,387 ± 27,654 are insects (class Insecta). Within Plantae, Tracheophyta (vascular plants) make up

3843-401: The variations in staining intensity in chromosomes . GC-rich isochores typically include many protein-coding genes within them, and thus determination of GC-ratios of these specific regions contributes to mapping gene-rich regions of the genome. Within a long region of genomic sequence, genes are often characterised by having a higher GC-content in contrast to the background GC-content for

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3906-429: The virus species " Salmonid herpesvirus 1 ", " Salmonid herpesvirus 2 " and " Salmonid herpesvirus 3 " are all within the genus Salmonivirus ; however, the genus to which the species with the formal names " Everglades virus " and " Ross River virus " are assigned is Alphavirus . As with scientific names at other ranks, in all groups other than viruses, names of genera may be cited with their authorities, typically in

3969-611: Was created by Lehmann and Neumann in 1896 as a taxonomic group to contain the bacterial rods responsible for causing diphtheria. The genus was defined based on morphological characteristics. Based on studies of 16S rRNA , they have been grouped into the subdivision of Gram-positive Eubacteria with high G : C content, with close phylogenetic relationships to Arthrobacter , Mycobacterium , Nocardia , and Streptomyces . The term comes from Greek κορύνη, korýnē 'club, mace, staff, knobby plant bud or shoot' and βακτήριον, baktḗrion 'little rod'. The term "diphtheroids"

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