Anginosus streptococci

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The division of living beings into systematics is a continuous subject of research. Different systematic classifications exist side by side and one after the other. The taxon treated here has become obsolete due to new research or is not part of the group systematics presented in the German-language Wikipedia.

Anginosus streptococci are gram-positive , spherical bacteria from the genus Streptococcus ( streptococci ). It is not a single species , but rather a group of multiple species that form a subgroup of the Viridans streptococci . They are also known as the Streptococcus anginosus group or the anginosus group for short. Sometimes the term “ Streptococcus milleri ” is also found, but it is misleading because a binomial refers to a species. After this no longer recognized species, the group is also called Milleri group or Streptococcus milleri group. The representatives of the group show different haemolysis behavior on blood agar , and they also differ in other characteristics. The establishment of the species Streptococcus anginosus , which gives this group its name , is considered certain . In addition, other bacterial strains are also included in this group, the recognition of which as a separate species is controversial.

features

" Streptococcus milleri " was first described in 1956 by Otto Guthof . He defined it as a non- hemolytic from festering abscesses of the oral cavity isolated streptococci, the arginine and esculin hydrolysis and at 45 ° C in Galle - Agar but not grow, sorbitol and mannitol can metabolize. Anginosus streptococci are cocci- shaped to ovoid cells that are arranged in pairs (diplococci) or in chains. Like all members of the genus , they do not form endospores . The Gram stain is positive. The representatives of the anginosus streptococci often grow as particularly small colonies (diameter smaller than 0.5 mm) on solid nutrient media , this is particularly typical for the so-called “minute strains”.

Although they form a subgroup of the viridans streptococci ("greening streptococci"), the name of which can be traced back to the α-hemolysis they carry out , the anginosus streptococci do not show any uniform hemolytic behavior . There are α-, β- and γ-hemolytic bacterial strains - the latter strain does not perform hemolysis. Beta hemolysis is carried out by 25–29% of the strains described. Streptococcus milleri group could the antigens of Lancefield group have A, C, F, or G. Lancefield group A antigens are actually typical of the so-called A streptococci , to which S. pyogenes in particular belongs. Less than 10% of the anginosus streptococci belong to Lancefield group A and can therefore be confused with S. pyogenes in the context of serological diagnostics . Lancefield group F antigens are found particularly frequently, and there are also representatives that do not have any of the antigens used for the Lancefield classification.

Any necessary antimicrobial therapy for infections with Streptococcus anginosus, S. intermedius and the S. constellatus group is carried out with antibiotics. Penicillin , ceftriaxone , cefotaxime , clindamycin and vancomycin are suitable for this .

Occurrence

As is typical for the viridans streptococci (or “ oral streptococci”), the anginosus streptococci also occur frequently in the oral cavity and in the ear, nose and throat area of humans. However, some species were isolated from other parts of the body when examining clinical specimens. In the context of abdominal infections, they were found in the abdominal cavity and in liver abscesses .

Systematics and taxonomy

The strains belonging to the anginosus streptococci are representatives of the genus Streptococcus in the family of the Streptococcaceae in the order of the Lactobacillales (lactic acid bacteria), which belong to the firmicutes division .

The name " Streptococcus milleri " goes back to Otto Guthof, who first described the bacterium in 1956 . The taxonomy and nomenclature of the representatives of the genus Streptococcus is characterized by many changes, this applies to this subgroup in particular. In addition to “ Streptococcus milleri ”, the “minute strains” (1934), “ Streptococcus MG ” (1944) and the streptococci of Lancefield group F (1962) were described, which despite some differences were combined into a common group. In 1977 Richard R. Facklam pointed out the similarity of many members of this group with Streptococcus anginosus , Streptococcus constellatus and Streptococcus intermedius . However, he did not suggest to integrate them into a larger group, but rather, they by their ability to lactose to use to distinguish: The lactose-positive counted representatives he "to the group S. MG-intermedius ", the lactose-negative representatives of the group" S. anginosus constellatus ". This system prevailed among US microbiologists , while European scientists accepted the idea of ​​a large, joint group.

In the 1980 Approved Lists of Bacterial Names based on the newly organized bacteriological code , the species S. anginosus , S. constellatus and S. intermedius are listed , but not " S. milleri " . In view of the different systematics in the USA and Europe, Facklam proposed in 1984 that the α- and γ-hemolytic strains should be classified as S. intermedius (lactose-positive) and S. constellatus (lactose-negative), while the β-hemolytic strains Strains are representatives of S. anginosus . In 1987, Alan L. Coykendall et al. the results of their investigation of bacterial strains that were assigned to " S. milleri " in 1956 and compared with bacterial strains of the other three species established at the time. The examination included phenotypic and genetic examinations such as DNA-DNA hybridization and determination of the GC content . The type strains of S. anginosus and S. constellatus as well as strains of the Lancefield group F showed a very high genetic similarity. According to the scientists, the results of the study showed more similarities than differences, so they suggested that the three species and other bacterial strains belonging to the group be combined into one species whose name, according to the priority rule, is Streptococcus anginosus .

This was refuted in 1991 by molecular biological studies. It could also be proven that “ S.milleri ” is not an independent species, but that the so-called isolates can be identified as S. anginosus or, in another case, as S. intermedius . At the same time it was proposed to recognize three species S. anginosus , S. constellatus and S. intermedius , which are closely related to each other. Subsequent phylogenetic studies in the 1990s and early 21st century yielded conflicting results that confirm either one of the proposals. In addition, there are also differences within the three species, so that three subspecies ( S. constellatus subsp. Constellatus , S. constellatus subsp. Pharyngis and S. constellatus subsp. Viborgensis ) were already established in Streptococcus constellatus .

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literature

  • Jeremy M. Hardie, Robert A. Whiley: The Genus Streptococcus - Oral (Chapter 1.2.2) . In: 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 978-0-387-25494-4 , pp. 76-107 , doi : 10.1007 / 0-387-30744-3_2 .
  • Jan Adriaan Jacobs: Streptococcus milleri: Relevance of species . In: Dissertation at the Rijksuniversiteit Limburg te Maastricht . 1996, p. 1–113 ( PDF, 9.1 MB [accessed July 23, 2014]).

Individual evidence

  1. ↑ a b Otto Guthof: About pathogenic greening streptococci; Streptococcal findings in dentogenic abscesses and infiltrates in the oral cavity . In: Central Journal for Bacteriology, Microbiology and Hygiene. 1. Dept. Originals A, Medical Microbiology, Infectious Diseases and Parasitology . tape 166 , no. 7–8 , 1956, pp. 553-564 .
  2. ↑ a b c Jan Adriaan Jacobs: Streptococcus milleri: Relevance of species . In: Dissertation at the Rijksuniversiteit Limburg te Maastricht . 1996, p. 1–113 ( PDF, 9.1 MB [accessed July 23, 2014]).
  3. ↑ a b c d e f Jeremy M. Hardie, Robert A. Whiley: The Genus Streptococcus - Oral. In: The Prokaryotes. A Handbook on the Biology of Bacteria, Volume 4: Bacteria: Firmicutes, Cyanobacteria. Edited by M. Dworkin, S. Falkow, E. Rosenberg, K.-H. Schleifer, E. Stackebrandt. 3. Edition. Springer Verlag, New York 2006, ISBN 978-0-387-25494-4 , pp. 76-107
  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. 267.
  5. ^ A b Jean Euzéby, Aidan C. Part: Genus Streptococcus. In: List of Prokaryotic names with Standing in Nomenclature ( Systematics of Bacteria ). Retrieved July 22, 2014 .
  6. ^ Richard R. Facklam: Physiological differentiation of viridans streptococci. In: Journal of clinical microbiology. Volume 5, No. 2, February 1977, pp. 184-201, ISSN  0095-1137 . PMID 845245 . PMC 274561 (free full text).
  7. ↑ Approved Lists of Bacterial Names . In: VBD Skerman, Vicki McGowan, PHA Sneath (Eds.): International Journal of Systematic Bacteriology . tape 30 , no. 1 , 1980, p. 225-420 , doi : 10.1099 / 00207713-30-1-225 ( PDF, 17.0 MB [accessed April 13, 2014]). PDF, 17.0 MB ( Memento of the original from January 22, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  @1@ 2Template: Webachiv / IABot / ijs.sgmjournals.org
  8. ↑ AL Coykendall, PM Wesbecher, KB Gustafson: "Streptococcus milleri", Streptococcus constellatus, and Streptococcus intermedius Are Later Synonyms of Streptococcus anginosus. In: International Journal of Systematic Bacteriology. Volume 37, No. 3, July 1987, pp. 222-228, ISSN  0020-7713 . doi : 10.1099 / 00207713-37-3-222 .
  9. ^ RA Whiley, D. Beighton: Emended descriptions and recognition of Streptococcus constellatus, Streptococcus intermedius, and Streptococcus anginosus as distinct species. In: International journal of systematic bacteriology. Volume 41, No. 1, January 1991, pp. 1-5, ISSN  0020-7713 . PMID 1995029 .