Streptococcaceae

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Streptococcaceae
Light microscope image (phase contrast) of Streptococcus iniae

Light microscope image ( phase contrast ) of Streptococcus iniae

Systematics
Domain : Bacteria (bacteria)
Department : Firmicutes
Class : Bacilli
Order : Lactic acid bacteria (Lactobacillales)
Family : Streptococcaceae
Scientific name
Streptococcaceae
Deibel & Seeley 1974

Streptococcaceae form a family of gram-positive bacteria from the order of the Lactobacillales (lactic acid bacteria). There are many pathogens , but also harmless intestinal inhabitants of animals and humans and economically important representatives. Various species of the Lactococcus genus are important for the production of dairy products ( buttermilk , cheese, etc.). In the genus Streptococcus ( streptococci ) there are important pathogenic representatives.

features

The cells of these bacteria are mostly coccoid , and after cell division they can remain strung together, which leads to the appearance of chain cocci , also known as "streptococci", regardless of whether they belong to the genus Streptococcus . But the appearance of the diplococci also occurs in representatives of the family , it is typical for Streptococcus pneumoniae ( pneumococci ). The species of the Streptococcaceae do not form endospores and are not actively mobile . As representatives of the Firmicutes , they belong to the bacteria with a low GC content , i.e. a low proportion of the nucleobases guanine and cytosine in the bacterial DNA . The GC content ranges from 34 to 46  mole percent . As is typical of lactic acid bacteria lead them to produce energy, the lactic acid fermentation through, it includes Lactococcus - and Streptococcus species to the homofermentative species. The types are catalase- negative and oxidase -negative.

Systematics

Streptococcus is the type genus of the Streptococcaceae family. While the first description of this kind took place at the end of the 19th century, the family was only in 1974 Robert H. Deibel and Harry W. Seeley established. The taxonomy and nomenclature of the representatives of the genus Streptococcus have been shaped by many changes. The Lancefield classification was and is important for differentiation on the basis of antigens . Most of the streptococci of Lancefield group D (the so-called D streptococci) and Lancefield group N were established in the 1980s as separate genera Enterococcus and Lacotococcus , with Enterococcus later being placed in the Enterococcaceae family .

There are currently three genera of the Streptococcaceae family (as of 2014):

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literature

  • Martin Dworkin, Stanley Falkow, Eugene Rosenberg, Karl-Heinz Schleifer, Erko Stackebrandt (eds.): The Prokaryotes. A Handbook on the Biology of Bacteria, Volume 4: Bacteria: Firmicutes, Cyanobacteria . 3. Edition. Springer-Verlag, New York 2006, ISBN 0-387-25494-3 .
  • Paul Vos, George Garrity, Dorothy Jones, Noel R. Krieg, Wolfgang Ludwig, Fred A. Rainey, Karl-Heinz Schleifer, William B. Whitman: Bergey's Manual of Systematic Bacteriology: Volume 3: The Firmicutes . 2nd Edition. Springer-Verlag, New York 2009, ISBN 978-0-387-95041-9 .
  • Werner Köhler (ed.): Medical microbiology . 8th completely revised edition. Urban & Fischer, Munich et al. 2001, ISBN 3-437-41640-5 .

Individual evidence

  1. Michael T. Madigan, John M. Martinko, Jack Parker: Brock Microbiology. German translation edited by Werner Goebel, 1st edition. Spectrum Akademischer Verlag GmbH, Heidelberg / Berlin 2000, ISBN 978-3-8274-0566-1 , pp. 558-563, 693.
  2. ^ Jean Euzéby, Aidan C. Parte: Family Streptococcaceae. In: List of Prokaryotic names with Standing in Nomenclature ( LPSN ). Retrieved July 30, 2014 .

Web links

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