Streptococcus
Streptococcus pneumoniae secondary electron micrograph colored,
Streptococci ( Germanized plural from the Latinised singular Streptococcus, the στρεπτός from the two ancient Greek ingredients streptós, Necklace ' and κόκκος KOKKOS, core ', ' grain ' composed ) are bacteria of the genus Streptococcus, kokkal ( approximately spherical ), preferably in chains arranged gram- positive and aero -tolerant.
Properties
Spherical to ellipsoidal cells, diameter 0.5 - 2.0 microns arranged in pairs or in different long chains, gram- positive, motile not ( without active movement ), non-spore -forming, some species produce mucus sheaths. They are facultative anaerobes, aerotolerant, chemoorganotroph, fermentation, mainly carbohydrates utiwizing while mainly lactic acid homofermentative forming, catalase - negative, oxidase - negative, non-proteolytically, temperature range of growth and proliferation > 10 - < 45 ° C, optimum near 37 ° C.
Occurrence
Some streptococci belong to the normal bacterial community that settled in and on humans and mammals, but some can cause serious illness.
Classification, medical importance
It is divided by factors including the hemolysis in α -, β - and γ -hemolytic streptococci. β -hemolytic streptococci are divided according to the Lancefield classification on. Some streptococcal species come in many forms before with different types of antigens. So are 84 different strains of Streptococcus pneumoniae are known which differ in the structure of their polysaccharide capsule. Each of these strains is a different serotype of S. salivarius represents the polysaccharide capsule, for example, consists of a polymer of fructose, the Laevankapsel.
As viridans streptococci streptococci are known, identify the blood agar in a so-called α - hemolysis ( " greening " ), which means they attack the erythrocytes (red blood cells) in with degradation of hemoglobin, with greenish -products. They belong to the normal microorganisms colonization of the oral cavity. Many of them can lead to an inflammation of the endocardium ( endocarditis) in crossing the blood. Among them is the species Streptococcus mutans, which plays an important role in tooth decay by forming a hand firmly adhering exopolysaccharides and on the other hand from carbohydrates lactic acid that attacks the tooth substance belongs. Streptococci also call ear-nose -throat disorders ( ENT diseases ) out.
β -haemolytic streptococci serogroup B may pose a risk during birth for newborns. These bacteria can be transmitted at vaginal delivery from the mother. Particularly in preterm infants, these bacteria to sepsis, meningitis ( meningitis ) and pneumonia can cause. These bacteria are detected by swabbing the vaginal or perineal area. Treatment is carried out for the period of confinement (from rupture of membranes or at the onset of first contractions ) by administering antibiotics to women in labor.
Streptococcal serogroup D are usually treated as a separate entity (see enterococci ).
Species
- S. agalactiae Lehmann and Neumann 1896
- S. anginosus ( Andrewes & Horder 1906) Smith & Sherman 1938
- S. avium
- S. bovis Orla -Jensen 1919
- S. canis Devriese et al. 1986
- S. difficilis Corrig. Eldar et al. 1995
- S. durans (ex Sherman & Wing 1937) Knight et al. 1984
- S. dysgalactiae (ex Diernhofer 1932) Garvie et al. 1983
- S. equi Sand & Jensen 1888
- P gallolyticus Osawa et al. 1996
- S. iniae Pier & Madin 1976
- S. mitis Andrewes & Horder 1906
- S. mutans Clarke 1924
- S. pasteurianus Poyart et al. 2002
- S. pneumoniae (Klein 1884) Chester 1901
- Porcinus S. Collins et al. 1985
- S. pyogenes Rosenbach 1884
- S. salivarius Andrewes and Horder 1906
- S. sanguinis Corrig. White and Niven 1946
- S. suis (ex Elliot 1966) Kilpper - Balz & Schleifer 1987
- S. uberis Diernhofer 1932
- S. viridans ( collective term )
Benefit
Streptokinase from Streptococcus is obtained which is used in fibrinolysis as Fibronolyseaktivator. See also BLIS as prophylaxis against periodontal disease and the development of the intestinal flora by antibiotics or fungal treatment.