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29-487: See text Treponema is a genus of spiral-shaped bacteria. The major treponeme species of human pathogens is Treponema pallidum , whose subspecies are responsible for diseases such as syphilis , bejel , and yaws . Treponema carateum is the cause of pinta . Treponema paraluiscuniculi is associated with syphilis in rabbits . Treponema succinifaciens has been found in the gut microbiome of traditional rural human populations. The currently accepted taxonomy

58-462: A bacilliform bacterium or often just a rod (when the context makes the sense clear), is a rod-shaped bacterium or archaeon . Bacilli are found in many different taxonomic groups of bacteria. However, the name Bacillus , capitalized and italicized , refers to a specific genus of bacteria. The name Bacilli , capitalized but not italicized, can also refer to a less specific taxonomic group of bacteria that includes two orders, one of which contains

87-507: A morphology of diplococcus, M. catarrhalis , a salient pathogen contributing to infections in the human body. The species Streptococcus pneumoniae belongs to the genus Streptococcus and the family Streptococcaceae . The genus Streptococcus has around 129 species and 23 subspecies that benefit many microbiomes on the human body. There are many species that show non-pathogenic characteristics; however, there are some, like S. pneumoniae , that exhibit pathogenic characteristics in

116-462: A significant role in the pathogenesis of human periodontal disease . The class currently consists of 14 validly named genera across 4 orders and 5 families. The orders Brachyspirales , Brevinematales and Leptospirales each contain a single family, Brachyspiraceae , Brevinemataceae and Leptospiraceae , respectively. The Spirochaetales order harbours two families, Spirochaetaceae and Borreliaceae . Molecular markers in

145-548: Is a Gram-negative coccobacillus prevalent in subgingival plaques. Acinetobacter strains may grow on solid media as coccobacilli. Bordetella pertussis is a Gram-negative coccobacillus responsible for causing whooping cough . Yersinia pestis , the bacterium that causes plague , is also coccobacillus. Coxiella burnetti is also a coccobacillus. Bacteria from the genus Brucella are medically important coccobacilli that cause brucellosis . Haemophilus ducreyi , another medically important Gram-negative coccobacillus,

174-487: Is a major human pathogen. It can infect almost any tissue in the body, frequently the skin. It often causes nosocomial (hospital-acquired) infections. Diplococci are pairs of cocci. Examples of gram-negative diplococci are Neisseria spp. and Moraxella catarrhalis . Examples of gram-positive diplococci are Streptococcus pneumoniae and Enterococcus spp. Presumably, diplococcus has been implicated in encephalitis lethargica . The genus Neisseria belongs to

203-453: Is a type of bacterium with a shape intermediate between cocci (spherical bacteria) and bacilli (rod-shaped bacteria). Coccobacilli, then, are very short rods which may be mistaken for cocci. The word coccobacillus reflects an intermediate shape between coccus (spherical) and bacillus (elongated). Haemophilus influenzae , Gardnerella vaginalis , and Chlamydia trachomatis are coccobacilli. Aggregatibacter actinomycetemcomitans

232-609: Is an English loanword of a modern or Neo-Latin noun, which in turn stems from the Greek masculine noun κόκκος ( cóccos ) meaning 'berry'. Important human diseases caused by coccoid bacteria include staphylococcal infections, some types of food poisoning , some urinary tract infections , toxic shock syndrome , gonorrhea , as well as some forms of meningitis , throat infections, pneumonias , and sinusitis . Coccoid bacteria often occur in characteristic arrangements and these forms have specific names as well; listed here are

261-2575: Is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI). Gracilinema caldarium (Pohlschröder, Leschine & Canale-Parola 1995) Brune et al. 2022 Zuelzera stenostrepta (Zuelzer 1912) Brune et al. 2022 Breznakiella homolactica Song et al. 2022 Helmutkoenigia isoptericolens (Dröge et al. 2008) Brune et al. 2022 Leadbettera azotonutricia (Graber et al. 2004) Brune et al. 2022 Treponema primitia Graber, Leadbetter & Breznak 2004 Brucepastera parasyntrophica Song et al. 2023 Teretinema zuelzerae (Canale-Parola 1980) Song et al. 2023 T. medium Umemoto et al. 1997 T. phagedenis (Noguchi 1912) Brumpt 1922 ex Kuhnert et al. 2020 T. denticola (Flügge 1886) Brumpt 1925 ex Chan et al. 1993 T. pedis Evans et al. 2009 T. putidum Wyss et al. 2004 T. brennaborense Schrank et al. 1999 T. lecithinolyticum Wyss et al. 1999 T. maltophilum Wyss et al. 1996 T. pectinovorum Smibert & Burmeister 1983 T. bryantii Stanton & Canale-Parola 1980 T. rectale Staton et al. 2017 T. berlinense Nordhoff et al. 2005 T. porcinum Nordhoff et al. 2005 T. peruense Belkhou et al. 2021 T. succinifaciens Cwyk and Canale-Parola 1981 T. ruminis Newbrook et al. 2017 T. saccharophilum Paster & Canale-Parola 1986 T. amylovorum Wyss et al. 1997 T. parvum Wyss et al. 2001 non Dobell 1912 T. s. paredis Smibert, Johnson & Ranney 1984 T. s. buccale Smibert, Johnson & Ranney 1984 T. s. socranskii Smibert, Johnson & Ranney 1984 Gracilinema caldarium Breznakiella homolactica Leadbettera azotonutricia Treponema primitia " Ca. Gallitreponema excrementavium" Gilroy et al. 2021 " Ca. Avitreponema avistercoris" Gilroy et al. 2021 Brucepastera parasyntrophica T. pedis T. denticola T. putidum T. medium " T. vincentii " (Blanchard 1906) Brumpt 1922 ex Smibert 1984 T. pallidum (Schaudinn & Hoffmann 1905) Schaudinn 1905 [incl. Treponema paraluiscuniculi (Jacobsthal 1920) Smibert 1974 ] T. phagedenis Treponema brennaborense " Ca. Treponema excrementipullorum" Gilroy et al. 2021 Spiral bacteria#Spirochete Generally,

290-550: Is gram-negative and frequently has external amphitrichous or lophotrichous flagella. Examples include: A spirochete (plural spirochetes) is a very thin, elongate, flexible, spiral bacteria that is motile via internal periplasmic flagella inside the outer membrane. They comprise the phylum Spirochaetes . Owing to their morphological properties, spirochetes are difficult to Gram-stain but may be visualized using dark field microscopy or Warthin–Starry stain . Examples include: Helicobacter species are helically shaped,

319-440: Is observed in sexually transmitted disease, chancroid, of Third World countries. Spiral bacteria are another major bacterial cell morphology. Spiral bacteria can be sub-classified as spirilla, spirochetes, or vibrios based on the number of twists per cell, cell thickness, cell flexibility, and motility. Bacteria are known to evolve specific traits to survive in their ideal environment. Bacteria-caused illnesses hinge on

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348-537: The Spirochaetales order. CSIs have also been found that further differentiate taxonomic groups within the Borreliaceae family that further delineate evolutionary relationships that are in accordance with physical characteristics such as pathogenicity (viz. Borrelia emend. Borreliella gen. nov.). However, this study has been criticized, and other studies using different approaches do not support

377-544: The CSI is exclusively shared by members within this phylum, it has been postulated that it may be related to the characteristic flagellar properties observed among Spirochaetota species. Historically, all families belonging to the Spirochaetota phylum were assigned to a single order, the Spirochaetales . However, the current taxonomic view is more connotative of accurate evolutionary relationships. The distribution of

406-628: The Latin coccinus (scarlet) and derived from the Greek kokkos (berry)) is any microorganism (usually bacteria ) whose overall shape is spherical or nearly spherical. Coccus refers to the shape of the bacteria, and can contain multiple genera, such as staphylococci or streptococci. Cocci can grow in pairs, chains, or clusters, depending on their orientation and attachment during cell division. In contrast to many bacilli-shaped bacteria, most cocci bacteria do not have flagella and are non-motile. Cocci

435-405: The bacteria’s physiology and their ability to interact with their environment, including the ability to shapeshift . Researchers discovered a protein that allows the bacterium Vibrio cholerae to morph into a corkscrew shape that likely helps it twist into — and then escape — the protective mucus that lines the inside of the gut. A spirillum (plural spirilla) is a rigid spiral bacterium that

464-450: The bacterium within the periplasmic space (between the inner and outer membranes) where they project backwards to extend the length of the cell. These cause a twisting motion which allows the spirochaete to move. When reproducing, a spirochaete will undergo asexual transverse binary fission . Most spirochaetes are free-living and anaerobic , but there are numerous exceptions. Spirochaete bacteria are diverse in their pathogenic capacity and

493-541: The basic forms as well as representative bacterial genera : The gram-positive cocci are a large group of bacteria with similar morphology. All are spherical or nearly so, but they vary considerably in size. Members of some genera are identifiable by the way cells are attached to one another: in pockets, in chains, or grape-like clusters. These arrangements reflect patterns of cell division and that cells stick together. Sarcina cells, for example, are arranged in cubical pockets because cell division alternates regularly among

522-510: The basic morphologies are spheres (coccus) and round-ended cylinders or rod shaped (bacillus). But, there are also other morphologies such as helically twisted cylinders (example Spirochetes ), cylinders curved in one plane (selenomonads) and unusual morphologies (the square, flat box-shaped cells of the Archaean genus Haloquadratum ) . Other arrangements include pairs, tetrads, clusters, chains and palisades. A coccus (plural cocci , from

551-484: The ecological niches that they inhabit, as well as molecular characteristics including guanine-cytosine content and genome size. Many organisms within the Spirochaetota phylum cause prevalent diseases. Pathogenic members of this phylum include the following: Salvarsan , the first partially organic synthetic antimicrobial drug in medical history, was effective against spirochaetes and primarily used to cure syphilis . Additionally, oral spirochaetes are known to play

580-417: The family Neisseriaceae. This genus, Neisseria , is divided into more than ten different species, but most of them are gram negative and coccoid. The gram-negative, coccoid species include: Neisseria cinerea , N. gonorrhoeae , N. polysaccharea , N. lactamica , N. meningitidis , N. mucosa , N. oralis and N. subflava . The most common of these species are

609-468: The form of conserved signature indels (CSIs) and CSPs have been found specific for each of the orders, with the exception of Brevinimetales , that provide a reliable means to demarcate these clades from one another within the diverse phylum. Additional CSIs have been found exclusively shared by each family within the Spirochaetales . These molecular markers are in agreement with the observed phylogenetic tree branching of two monophyletic clades within

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638-420: The genus Bacillus . When the word is formatted with lowercase and not italicized, 'bacillus', it will most likely be referring to shape and not to the genus. Bacilliform bacteria are also often simply called rods when the bacteriologic context is clear. Bacilli usually divide in the same plane and are solitary, but can combine to form diplobacilli, streptobacilli, and palisades. There is no connection between

667-412: The human body. The genus Enterococcus belongs to the family Enterococcaceae . This genus is divided into 58 species and two subspecies. These gram-positive, coccoid bacteria were once thought to be harmless to the human body. However, within the last ten years, there has been an influx of nosocomial pathogens originating from Enterococcus bacteria. A bacillus ( pl. : bacilli ), also called

696-542: The most common example of which is Helicobacter pylori . A helical shape is seen to be better suited for movement of bacteria in a viscous medium. Spirochetes A spirochaete ( / ˈ s p aɪ r oʊ ˌ k iː t / ) or spirochete is a member of the phylum Spirochaetota (also called Spirochaetes / ˌ s p aɪ r oʊ ˈ k iː t iː z / ), which contains distinctive diderm (double-membrane) Gram-negative bacteria , most of which have long, helically coiled (corkscrew-shaped or spiraled, hence

725-399: The name) cells. Spirochaetes are chemoheterotrophic in nature, with lengths between 3 and 500 μm and diameters around 0.09 to at least 3 μm. Spirochaetes are distinguished from other bacterial phyla by the location of their flagella , called endoflagella , or periplasmic flagella , which are sometimes called axial filaments . Endoflagella are anchored at each end (pole) of

754-566: The pathogenic N. meningitidis and N. gonorrhoeae . The genus Moraxella belongs to the family Moraxellaceae . This genus, Moraxellaceae , comprises gram-negative coccobacilli bacteria: Moraxella lacunata , M. atlantae , M. boevrei , M. bovis , M. canis , M. caprae , M. caviae , M. cuniculi , M. equi , M. lincolnii , M. nonliquefaciens , M. osloensis , M. ovis , M. saccharolytica , and M. pluranimalium . However, only one has

783-509: The proposed split. The new naming system for the Lyme and relapsing fever Borrelia has not been adopted by the scientific literature. A CSI has also been found exclusively shared by all Spirochaetota species. This CSI is a 3 amino acid insert in the flagellar basal body rod protein FlgC which is an important part of the unique endoflagellar structure shared by Spirochaetota species. Given that

812-425: The shape of a bacterium and its color upon Gram staining ; there are both gram-positive rods and gram-negative rods. MacConkey agar can be used to distinguish among gram-negative bacilli such as E. coli and salmonella . Bacilli usually divide in the same plane and are solitary, but can combine to form diplobacilli, streptobacilli, and palisades. A coccobacillus (plural coccobacilli ), or bacillococcus ,

841-748: The three perpendicular planes. Streptococcus spp. resemble a string of beads because division always occurs in the same plane. Some of these strings, for example, S. pneumoniae , are only two cells long. They are called diplococci. Species of Staphylococcus have no regular plane of division. They form grape-like structures. The various gram-positive cocci differ physiologically and by habitat. Micrococcus spp. are obligate aerobes that inhabit human skin. Staphylococcus spp. also inhabit human skin, but they are facultative anaerobes. They ferment sugars, producing lactic acid as an end product. Many of these species produce carotenoid pigments, which color their colonies yellow or orange. Staphylococcus aureus

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