Klebsiella

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Klebsiella
Klebsiella pneumoniae (secondary electron microscope image)

Klebsiella pneumoniae
(secondary electron microscope image)

Systematics
Domain : Bacteria (bacteria)
Department : Proteobacteria
Class : Gammaproteobacteria
Order : Enterobacterales
Family : Enterobacteriaceae
Genre : Klebsiella
Scientific name
Klebsiella
Trevisan 1885
(Approved Lists 1980)
emend. Drancourt et al. 2001

The genus Klebsiella includes gram - negative rod-shaped bacteria of the Enterobacteriaceae family . They were named after the East Prussian bacteriologist Edwin Klebs . The bacteria have no active movement and are surrounded by a mucous capsule ( glycocalyx ). They live under oxic conditions , i.e. in the presence of oxygen , aerobically, but can also live without oxygen, i. i.e., they are facultatively anaerobic . Typical for Klebsiella is a biofilm that develops on the colonies .

Klebsiella species live in the soil , in bodies of water and on grain . Of the Klebsiella species, Klebsiella granulomatis are medically relevant as the causative agent of Granuloma inguinale , Klebsiella pneumoniae and Klebsiella aerogenes as residents of the gastrointestinal tract . All species are insensitive ( resistant ) to penicillin . As the causative agent of infectious diseases acquired in hospital (see nosocomial infections ), K. pneumoniae is of particular importance , alongside K. aerogenes , especially when it comes to multi-resistant bacterial strains .

metabolism

The members of the genus Klebsiella are chemoorganotrophic , i. In other words, they break down organic substances to generate energy. They are facultatively anaerobic : If oxygen is present ( oxic milieu ), they have an oxidative energy metabolism , they oxidize the organic substances to carbon dioxide and water; when no oxygen is available, i.e. under anoxic conditions, they use 2,3-butanediol fermentation to generate energy. The end product here is mainly the alcohol 2,3-butanediol and carbon dioxide in large quantities , as well as in small quantities and the like. a. different acids.

In other genera of the Enterobacteriaceae family such. B. Escherichia and Salmonella , the mixed acid fermentation is the anaerobic energy metabolism, in contrast to the butanediol fermentation , large amounts of acids ( acetic acid , lactic acid and succinic acid ) are produced as end products, but no butanediol. This feature is used to differentiate the Enterobacteriaceae genera. The Voges-Proskauer test is used to detect acetoin , an intermediate product in 2,3-butanediol fermentation. Klebsiella reacts positively to this.

Systematics and taxonomy

Currently (as of 2019) the genus includes the following species and subspecies , K. pneumoniae is the type species .

Synonyms (selection)

This section lists bacteria that previously belonged to the genus Klebsiella , but have now been assigned to other genera or, conversely, have been transferred from other genus to Klebsiella .

  • K. ozeanae ( Abel 1893) Bergey et al. 1925: Now as a subspecies Klebsiella pneumoniae subsp. oceanae led.
  • K. rhinoscleromatis Trevisan 1887: Now also placed as a subspecies of K. pneumoniae .
  • Calymmatobacterium granulomatis Aragão & Vianna 1913 (Approved Lists 1980): Now added to the genus as K. granulomatis . Other synonyms: " Encapsulatus inguinalis " Bergey 1923, " Donovania granulomatis " Anderson et al. 1944.
  • Enterobacter aerogenes Hormaeche & Edwards 1960 and Klebsiella mobilis Bascomb et al. 1971: Both names are homotypical synonyms , as both species have the same type stem. According to current taxonomy , it is Klebsiella aerogenes ( Hormaeche & Edwards 1960) Tindall et al. 2017 comb. nov., Enterobacter aerogenes Hormaeche & Edwards 1960 is the basonym , while Klebsiella mobilis Bascomb et al. 1971 may no longer be used as a synonym, as the epithet is not allowed.
  • " Klebsiella aerogenes " ( Kruse ) Taylor et al. 1956: Is not identical to Klebsiella aerogenes ( Hormaeche & Edwards 1960) Tindall et al. 2017 comb. nov., this bacterium was assigned to the taxon Klebsiella pneumoniae subsp. pneumoniae .

The following species were added to the genus Raoultella :

  • Klebsiella terrigena Izard et al. 1981
  • Klebsiella ornithinolytica Sakazaki et al. 1989
  • Klebsiella planticola Bagley et al. 1982 (synonym K. trevisanii Ferragut et al. 1983)

Medical importance

Klebsiella can cause pneumonia, urinary tract infection, bacteremia, sepsis, peritonitis, and intra-abdominal abscesses. Nosocomial infections with Klebsiella species occur. For the antibiotic treatment of Klebsiella diseases, it is important to differentiate between wild-type and ESBL-positive strains .

swell

literature

Systematics and synonyms according to:

Individual evidence

  1. ^ Jean Euzéby, Aidan C. Parte: Genus Klebsiella. In: List of Prokaryotic names with Standing in Nomenclature, Systematics of Bacteria (LPSN) . Retrieved May 24, 2018 .
  2. ↑ a b B. J. Tindall, G. Sutton, GM Garrity: Enterobacter aerogenes Hormaeche and Edwards 1960 (Approved Lists 1980) and Klebsiella mobilis Bascomb et al. 1971 (Approved Lists 1980) share the same nomenclatural type (ATCC 13048) on the Approved Lists and are homotypic synonyms, with consequences for the name Klebsiella mobilis Bascomb et al. 1971 (Approved Lists 1980). In: International Journal of Systematic and Evolutionary Microbiology. Volume 67, 2017, pp. 502-504, doi : 10.1099 / ijsem.0.001572 .
  3. ↑ Michel Drancourt, C. Bollet, Angelino Carta, P. Rousselier: Phylogenetic analyzes of Klebsiella species delineate Klebsiella and Raoultella gen. Nov., With description of Raoultella ornithinolytica comb. nov., Raoultella terrigena comb. nov. and Raoultella planticola comb. nov. In: International Journal of Systematic and Evolutionary Microbiology . Volume 51, 2001, pp. 925-932, ISSN  1466-5026 . doi : 10.1099 / 00207713-51-3-925 .
  4. ^ Marianne Abele-Horn: Antimicrobial Therapy. Decision support for the treatment and prophylaxis of infectious diseases. With the collaboration of Werner Heinz, Hartwig Klinker, Johann Schurz and August Stich, 2nd, revised and expanded edition. Peter Wiehl, Marburg 2009, ISBN 978-3-927219-14-4 , p. 264 ( Klebsiella spp. ).