Brothels

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Brothels
Bordetella bronchiseptica (scanning electron microscope image)

Bordetella bronchiseptica
(scanning electron microscope image)

Systematics
Domain : Bacteria (bacteria)
Department : Proteobacteria
Class : Betaproteobacteria
Order : Burkholderiales
Family : Alcaligenaceae
Genre : Brothels
Scientific name
Bordetella
Moreno-Lopez 1952

Bordetelles are bacteria that belong to the genus Bordetella . These are gram-negative , short, rod-shaped cells that mostly grow aerobically . Almost all species live parasitically on humans, animals or birds, some of them are pathogens , most notably the mainly by Bordetella pertussis caused whooping cough .

features

Appearance

The cells of Bordetella species are short to cocoid (spherical) rods ; in the Gram stain they behave gram- negative. In the light microscopic picture they appear individually, in pairs or in groups. Endospores are not formed. The cells have pili (fimbriae) on their surface. Only a few species move independently, they are motile .

Growth and metabolism

These are almost always strictly aerobic bacteria that need oxygen for cell respiration . An exception is Bordetella petrii , which can also grow anaerobically. They reproduce well at temperatures in the range of 30-37 ° C. The catalase test is positive. Bordetella species are asaccharolytic, i. That is, they cannot utilize sugar (e.g. glucose ). Under aerobic conditions, all species can utilize citrate as an energy source and to build up cellular substances.

Gelatine cannot be broken down by hydrolysis , nor does aesculin hydrolysis take place. The Voges-Proskauer test for acetoin formation and the indole test are negative. On the other hand, they can reduce the redox dye tetrazolium to its colored form. The Bordet-Gengou blood agar and the Regan-Lowe nutrient medium are suitable for cultivating many Bordetella species , and this contains activated charcoal (see evidence for B. parapertussis ).

The differentiation of the species discovered first is difficult, since the three species show similarities in many metabolic-physiological and biochemical characteristics, but they can be differentiated on the basis of the following characteristics. With the discovery of other Bordetella species, these distinguishing features were expanded.

Features for differentiating the classic Bordetellen ( B. parapertussis , B. pertussis and B. bronchiseptica ) and the species discovered since 1984
features B. parapertussis B. pertussis B. bronchiseptica B. avium B. hinzii B. holmesii B. trematum B. petrii
Motility - - + + + - + -
Oxidase test - + + + + - - +
Nitrate reduction (reduction of nitrate to nitrite) - - + - - - variable -
Urease + - variable - - - - -
Hemolysis + + + - k. D. - k. D. -
Growth on peptone -containing culture medium (without blood additive) + - + k. D. k. D. k. D. k. D. k. D.
Growth on MacConkey agar + - + + + - + +
Growth in a nutrient medium with 10% bile salts + - + k. D. k. D. k. D. k. D. k. D.
Growth in a nutrient medium with 6% NaCl - - + k. D. k. D. k. D. k. D. k. D.
Assimilation of Caprat - - variable - + - - -
Assimilation of D - gluconate - - - - - - - +
Assimilation of L - malate - - variable + + - + +
Assimilation of phenyl acetate - - + + + - + -

For some tests there are no data (no data) available for the species; a variable result is due to the fact that the bacterial strains of a species behave differently.

Chemotaxonomic Features

The GC content (the proportion of the nucleobases guanine and cytosine ) in the bacterial DNA is between 60 and 69 mol percent. The main menaquinone is Q-8. Vandamme et al. a. investigated the composition of the fatty acids in the membrane lipids as part of the first description of Bordetella trematum and compared them with the known species. Accordingly, there are no branched-chain fatty acids in Bordetella species . A few typical fatty acids in the cell membrane cannot be determined, but the fatty acids with the abbreviations C16: 0 (hexadecanoic acid or palmitic acid ) and C17: 0 cyclo are present in larger quantities (more than 30% each) . C17: 0 cyclo is heptadecanoic acid, which contains a ring in the carbon chain (as in the cycloalkanes ), fatty acids of this type are also typical of representatives of the genus Alicyclobacillus . In addition, lactobacillic acid was found in several of the Bordetella species examined , but only in a small proportion of 1–2%.

Pathogenicity

Bordetelles are often pathogenic ("pathogenic") and attack the ciliated epithelium of the respiratory tract of mammals, humans and birds. With the exception of B. petrii (risk group 1), all other species are assigned to risk group 2 by the Biological Agents Ordinance in conjunction with the TRBA ( Technical Rules for Biological Agents) 466 . For some species, however, it is noted in the classification that they are pathogenic for humans and vertebrates, but that normally there is no transmission between the two host groups or that humans are not affected under natural conditions.

Systematics

A bacterium of this genus ( Bordetella pertussis ) was isolated for the first time in 1906 by the Belgian microbiologists Jules Bordet and Octave Gengou . The species discovered first were often initially assigned to other genera (e.g. Bacillus , Haemophilus or Alcaligenes ). In 1952 the genus Bordetella was established by Manuel Moreno López , to which these bacteria were then placed. The generic name honors Jules Bordet. Bordetella pertussis is the type species of the genus. Currently (as of 2014) the genus includes the following species (species):

B. pertussis , B. parapertussis and B. bronchiseptica have been known since the first half of the 20th century; they are also referred to as "classic" Bordetella species. They are so closely related genetically that they are also discussed as subspecies of the same species. Phylogenetic examinations to elucidate the family relationships between the organisms mainly include the sequencing of the 16S rRNA, a typical representative of ribosomal RNA for prokaryotes . This shows that the genus Bordetella forms its own group, with the genera Achromobacter and Alcaligenes as closely related groups. Within the Bordetellen, B. petrii shows the greatest deviations (97.9–98.6% similarity in the sequence), followed by B. avium (98.7–98.8%) and B. trematum .

Individual evidence

  1. ↑ a b c d e f Horst Finger, Carl Heinz Wirsing von König: Bordetella (Chapter 31) . In: Samuel Baron (Ed.): Medical Microbiology . 4th edition. University of Texas Medical Branch at Galveston, Galveston (TX), USA 1996, ISBN 0-9631172-1-1 ( NCBI Bookshelf ).
  2. ↑ a b c d Mardjan Arvand: Bordetellen . In: Helmut Hahn, Stefan HE Kaufmann, Thomas F. Schulz, Sebastian Suerbaum (eds.): Medical microbiology and infectious diseases . 6th edition. Springer Verlag, Heidelberg 2009, ISBN 978-3-540-46359-7 , p. 302-307 .
  3. ↑ a b c d e f F. von Wintzingerode, A. Schattke u. a .: Bordetella petrii sp. nov., isolated from an anaerobic bioreactor, and emended description of the genus Bordetella. In: International journal of systematic and evolutionary microbiology. Volume 51, No. 4, July 2001, pp. 1257-1265, ISSN  1466-5026 . doi : 10.1099 / 00207713-51-4-1257 . PMID 11491321 .
  4. ^ R. Johnson, PHA Sneath: Taxonomy of Bordetella and Related Organisms of the Families Achromobacteraceae, Brucellaceae, and Neisseriaceae. In: International Journal of Systematic Bacteriology. Volume 23, No. 4, October 1973, pp. 381-404, ISSN  0020-7713 . doi : 10.1099 / 00207713-23-4-381 .
  5. ↑ a b c K. Kersters, K.-H. Hinz u. a .: Bordetella avium sp. nov., Isolated from the Respiratory Tracts of Turkeys and Other Birds. In: International Journal of Systematic Bacteriology. Volume 34, No. 1, January 1984, pp. 56-70, ISSN  0020-7713 . doi : 10.1099 / 00207713-34-1-56 .
  6. ↑ a b c d e f P. Vandamme, M. Heyndrickx, M. Vancanneyt, B. Hoste, P. De Vos, E. Falsen, K. Kersters, K.-H. Hinz: Bordetella trematum sp. nov., isolated from wounds and ear infections in humans, and reassessment of Alcaligenes denitrificans Rüger and Tan 1983. In: International journal of Systematic Bacteriology. Volume 46, No. 4, October 1996, pp. 849-858, ISSN  0020-7713 . doi : 10.1099 / 00207713-46-4-849 . PMID 8863408 .
  7. ↑ TRBA (Technical Rules for Biological Agents) 466: Classification of prokaryotes (Bacteria and Archaea) into risk groups. In: Website of the Federal Institute for Occupational Safety and Health (BAuA). April 25, 2012, p. 42 , accessed January 7, 2014 .
  8. ↑ M. Moreno-López: El genero Bordetella [The genus Bordetella]. In: Microbiologia Española. Volume 5, 1952, pp. 177-181.
  9. ^ Jean Euzéby, Aidan C. Parte: Genus Bordetella. In: List of Prokaryotic names with Standing in Nomenclature ( LPSN ). Retrieved March 4, 2014 .
  10. ↑ J. Park, Y. Zhang and a .: Comparative genomics of the classical Bordetella subspecies: the evolution and exchange of virulence-associated diversity amongst closely related pathogens. In: BMC genomics. Volume 13, October 2012, p. 545, ISSN  1471-2164 . doi : 10.1186 / 1471-2164-13-545 . PMID 23051057 . PMC 3533505 (free full text).

Web links

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