''Selenomonas sputigena'' is a species of

anaerobe An anaerobic organism or anaerobe is any organism that does not require molecular oxygen for growth. It may react negatively or even die if free oxygen is present. In contrast, an aerobic organism (aerobe) is an organism that requires an oxygenat ...

Gram-negative bacteria Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the Crystal violet, crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelo ...

that is found in the

upper respiratory tract The respiratory tract is the subdivision of the respiratory system involved with the process of conducting air to the alveoli for the purposes of gas exchange in mammals. The respiratory tract is lined with respiratory epithelium as respiratory ...

of humans. It is the

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

of the genus ''Selenomonas'', with the type strain VPI D 19B-28 (ATCC 35185). It is known to cause blood infection (

sepsis Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage of sepsis is followed by suppression of the immune system. Common signs and s ...

), gum inflammation (

periodontal disease Periodontal disease, also known as gum disease, is a set of inflammatory conditions affecting the tissues surrounding the teeth. In its early stage, called gingivitis, the gums become swollen and red and may bleed. It is considered the main c ...

), and

tooth decay Tooth decay, also known as caries,The word 'caries' is a mass noun, and is not a plural of 'carie'.'' is the breakdown of teeth due to acids produced by bacteria. The resulting cavities may be a number of different colors, from yellow to black ...

. It alone cannot damage the

tooth enamel Tooth enamel is one of the four major Tissue (biology), tissues that make up the tooth in humans and many animals, including some species of fish. It makes up the normally visible part of the tooth, covering the Crown (tooth), crown. The other ...

, but worsen the damage done by other bacteria such as ''

Streptococcus mutans ''Streptococcus mutans'' is a Facultative anaerobic organism, facultatively anaerobic, gram-positive coccus (round bacteria, bacterium) commonly found in the human oral cavity and is a significant contributor to dental caries, tooth decay. The m ...

,'' ''

Porphyromonas gingivalis ''Porphyromonas gingivalis'' belongs to the phylum Bacteroidota and is a nonmotile, Gram-negative, rod-shaped, anaerobic, pathogenic bacterium. It forms black colonies on blood agar. It is found in the oral cavity, where it is implicated in ...

'', ''

Treponema denticola ''Treponema denticola'' is a Gram-negative, obligate anaerobic, motile and highly proteolytic spirochete bacterium. It is one of four species of oral spirochetes to be reliably cultured, the others being ''Treponema pectinovorum, Treponema socr ...

'', and ''

Tannerella forsythia ''Tannerella forsythia'' is an anaerobic, Gram-negative bacterial species of the Bacteroidota phylum. It has been implicated in periodontal diseases and is a member of the red complex of periodontal pathogens. ''T. forsythia'' was previously ...

.'' ''S. sputigena'' was first noted by

Antonie van Leeuwenhoek Antonie Philips van Leeuwenhoek ( ; ; 24 October 1632 – 26 August 1723) was a Dutch microbiologist and microscopist in the Golden Age of Dutch art, science and technology. A largely self-taught man in science, he is commonly known as " ...

in 1683 from his microscopic observation of his own

sputum Sputum is mucus that is coughed up from the lower airways (the trachea and bronchi). In medicine, sputum samples are usually used for a naked-eye examination, microbiological investigation of respiratory infections, and Cytopathology, cytological ...

. However, it was first described by Carl Flügge in 1886, giving the name ''Spirillum sputigenum''. In 1922, Erwin Boskamp revised the name as ''S. sputigena,'' which was approved by the Judicial Commission of the International Committee on Systematic Bacteriology in 1958.

Discovery and identification

''S. sputigena'' is one of the earliest observed bacteria. In 1683, Dutch merchant-microscopist, Antonie van Leeuwenhoek, saw the organism from his own sputum. His drawing showed a structure with curved body, dotted lines coming from it that form a loop. German hygienist, Carl Flügge, first described the organisms as moving bacteria in 1886, identified them as ''

Spirillum ''Spirillum'' is a genus of Gram-negative bacteria in the family '' Spirillaceae'' of the '' Nitrosomonadales'' of the ''Betaproteobacteria''.Garrity, George M.; Brenner, Don J.; Krieg, Noel R.; Staley, James T. (eds.) (2005). Bergey's Manual o ...

'' bacteria and gave the name ''Spirillum sputigenum''. Willoughby Dayton Miller, American dentist, is sometimes attributed as the first to give the systematic classification allegedly in his works in the early 1880s. However, his dissertation at the

University of Berlin The Humboldt University of Berlin (, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany. The university was established by Frederick William III on the initiative of Wilhelm von Humbol ...

in which he reported was published only in 1887. He did give the first clear description as "rods, curved like commas, which show very active spiral movements." It is not known whether or not he introduced the name ''S. sputigenum'', but is obvious that the first definitive published description by Flügge was based on Miller's work. In 1906, German bacteriologist, Waldemar Loewenthal, described the cause of the bacterial spiral movement as flagellar motion, mentioning that the bacteria had a single flagellum on the concave side of their bodies. Distinction as a unique species was not universally accepted. The simple and inconspicuous structure of the bacterium led Hugo Carl Plaut to redescribed in 1909 as generic bacteria that were only in their developmental stages. In 1913, Czech zoologist Stanislaus von Prowazek noticed hitherto unknown bacteria from the blood samples of dead African game animals. He identified the bacteria as a novel group and assigned the genus name ''Selenomonas''. He compared the new bacteria with Flügge's ''S. sputigenum'' and ''Ancyromonas ruminantium'' that was described by French biologist Adrien Certes in 1889. The three bacteria were structurally similar. In 1922, Erwin Boskamp revised the name as ''Selenomonas sputigena,'' based on von Prowazek's description of the genus. In 1958, the genus was approved by the Judicial Commission of the International Committee on Systematic Bacteriology with ''S. sputigena'' as its type species. The Judicial Commission adopted the formal classification in its 1980 ''Approved Lists of Bacteria'' with the type strain of ''S. sputigena'' as ATCC 33150 (VPI 10068). Genetic study in 1985 established that the assigned type strain was inaccurate and showed that it should be ATCC 35185 (or VPI D 19B-28), which the Jusicial Commission approved in 1992.

Structure

''S. sputigena'', like other selenomonads, is typically

crescent A crescent shape (, ) is a symbol or emblem used to represent the lunar phase (as it appears in the northern hemisphere) in the first quarter (the "sickle moon"), or by extension a symbol representing the Moon itself. In Hindu iconography, Hind ...

shaped and flagellated bacterium. However, it can take variable forms depending on its growth conditions, such as short and curved "crescent moon" or S-shaped spiral rod. The short forms are about 1 to 1.5 μm long and 0.3 μm in thickness. The long spiral forms can be from 4 to 50 μm long. The spiral are more pronounced than in other species of selenomonads. It normally has a tuft of flagella, consisting of several individual fibres and which are normally projected from the curved side of the cell. Sometimes described as peritrichous, indicating that the flagella are distributed evenly throughout the cell surface, there can be few flagella or none depending on the growth condition, and the site of the flagellar origin can also be random. The dynamic arrangement of the flagella and the indistinct cytoplasmic structures led to several key misidentification. Loewenthal was the first to describe the presence of a single flagellum, as well as one or two nuclei in the bacterium. Observations in the 1920's also supported the description. For this reason, University of Birmingham bacteriologist M.H. Jeynes formally proposed in 1956 to reassign ''S. sputigena'' and the other selenomonads to a eukaryotic group, Protozoa. It is now known that the flagella are composed of the bacterial protein,

flagellin Flagellins are a family of proteins present in flagellated bacteria which arrange themselves in a hollow cylinder to form the filament in a bacterial flagellum. Flagellin has a mass on average of about 40,000 daltons. Flagellins are the princi ...

External links

KEGG data

Names for Life

NCBI Taxonomy

Profile at Bac Dive

References

{{Taxonbar, from=Q3954762 Bacteria described in 1886 Negativicutes Periodontal disorders