Staphylococcus

Staphylococcus aureus

Staphylococci ( Germanized plural from the Latinised singular Staphylococcus, the σταφυλή from the two ancient Greek ingredients staphylé, grape ' and κόκκος KOKKOS, core ', ' grain ' composed ) are plump, wine grapes similarly arranged, non-spore -forming gram-positive bacteria without active movement from the group the cocci.

  • 4.1 Coagulase-positive staphylococci
  • 4.2 Coagulase negative staphylococci
  • 4.3 Effect character
  • 4.4 symptoms

Features

Spherical cells, diameter 0.5-1.5 microns, single, arranged in pairs or in irregular ( wine grape -like ) clusters, gram- positive, motile not (no active movement ), facultative anaerobic, chemoorganotroph, energy metabolism and oxidative fermentation, usually catalase positive and oxidase negative. Optimum temperature of the growth and proliferation 30-37 ° C. Many species have a high to predominant proportion of branched chain fatty acids into their membrane lipids.

Occurrence

They colonize as commensals and pathogens ( pathogens ) the skin and mucous membranes of humans and warm-blooded vertebrates, and are also used in the environment (water, air, food ) before.

System

The classification of the genus Staphylococcus and their representatives is based on the usual in biology taxonomy. However, since many representatives are of medical importance, the division has proven after the coagulase reaction in this area.

Outer systematics

The genus Staphylococcus has been historically in the family of the Micrococcaceae. In the second edition of Bergey's Manual of Systematic Bacteriology was proposed in 2001, in a new family of " Staphylococcaceae " to classify them, the facultative anaerobes (except Staphylococcus aureus subsp anaerobius, which is adapted to sheep [ sheep adapted ] obligate anaerobic subspecies. ) Grow. This proposal was adopted in 2010 with the Validation List No. 132 in the International Journal of Systematic and Evolutionary Microbiology.

Inside systematics

In the genus Staphylococcus nearly 50 species are included. Many species are still divided into subspecies. A recent compilation of the ( English for " Bacteriological Code") recognized species according to the Bacteriological Code and subspecies can be found in the List of Prokaryotic names with Standing in Nomenclature ( LPSN ). A fact -based list is reproduced in section species ( species) and subspecies ( subspecies ).

Classification, medical importance

In medicine, a classification of staphylococci by the coagulase reaction in coagulase done ( in human medicine usually with Staphylococcus aureus equated ) and coagulase-negative staphylococci. In particular, multidrug-resistant strains ( MRSA) are a problem because of poor treatability with antibiotics.

Coagulase-positive staphylococci

The staphylococcal species with the highest pathogenic potency and generally one of the most important pathogens in humans, the coagulase-positive species:

  • Staphylococcus aureus ( complete: Staphylococcus aureus subsp aureus. )

So far only demonstrated in humans in animals or only very rarely associated with infections:

  • Staphylococcus Agnetis ( koagulasevariabel )
  • Staphylococcus aureus subsp. anaerobius
  • Staphylococcus delphini
  • Staphylococcus hyicus ( koagulasevariabel )
  • Staphylococcus intermedius (rare - especially after dog bites - even with human wound infections )
  • Staphylococcus lutrae
  • Staphylococcus pseudintermedius
  • Staphylococcus schleiferi subsp. coagulans

Coagulase negative staphylococci

The coagulase-negative staphylococci are usually colonizers of the skin and mucous membranes without clinical significance. However, in immunocompromised patients (ie, those in which drugs with the defense function of the immune system has been lowered, has weakened the immune system, such as after a transplant, or a disease ) and in connection with so-called polymer - associated infections, d. h colonization of plastic surfaces (eg, catheters, artificial heart valves, artificial joints; see biofilm ), the coagulase-negative staphylococci have medical significance. Of these, in particular the following species can humans appear:

The latter is a more coagulase species, however, associated with a specific disease (associated) is. This pathogen may be responsible for the dysuria syndrome in younger women as well as for non-specific urethritis ( urethritis ) in men.

Effect character

Poisoning caused by enterotoxins, which are excreted as metabolites in the surrounding substrate on the pathogen. The toxins are protein -like structure with molecular weights of 20,000-40,000 g · mol -1. Enterotoxin B, for example, consists of a single polypeptide in which 239 amino acid residues are lined up. The toxins can be distinguished by their immune biological behavior against each other. The enterotoxin A causes in doses as low as 1 ug in adults vomiting, enterotoxin B after 20 to 25 ng. First symptoms are an average of two to four hours after receiving a corresponding amount of toxin with the food, the range of variation between one-half and seven hours. The primary target for the emetic effect lies in the abdominal organs, via the vagus and sympathetic fibers reaching the vomiting center. Other points of attack for the toxin are kidneys, liver, lungs, gastrointestinal tract, various tissues and individual cells.

Symptoms

First, salivation, then nausea, retching, vomiting, diarrhea. Vomiting and diarrhea may be explosive at the same time. In severe cases it can lead to dehydration, shock states, come to the appearance of mucus and blood in stool and vomit and hypokalemic muscle paralysis. The body temperature is usually raised, often subnormal temperatures are measured. The restitution may occur within 24 hours or even take a few days to complete. Only rarely it comes to exitus, here mostly in newborns. With the tissue damaging effect of the toxin is the rapid increase in GOT activity in the blood serum in context, as well as the changes in the white blood cell count (leukocytosis just 30 minutes after oral intake, at higher doses with previous leukopenia, later marked left shift ), catecholamine and glucose increase, increase of residual N, plasma fibrinogen and inorganic phosphorus waste of serum protein, calcium and chlorine and finally reduction of the platelet count and serotonin.

Species ( species) and subspecies ( subspecies ) of the genus Staphylococcus

  • S. Agnetis Taponen et al. 2012
  • Arlettae S. Schleifer et al. 1985
  • S. aureus Rosenbach 1884 S. aureus subsp. anaerobius De La Fuente et al. 1985
  • S. aureus subsp. aureus Rosenbach 1884
  • S. capitis subsp. capitis Kloos and Schleifer 1975
  • S. capitis subsp. urealyticus Corrig. Bannerman and Kloos 1991
  • S. carnosus subsp. carnosus Schleifer and Fischer 1982
  • S. carnosus subsp. utilis Probst et al. 1998
  • S. cohnii subsp. cohnii Schleifer and Kloos 1975
  • S. cohnii subsp. urealyticus Corrig. Kloos and Wolf Hollow 1991
  • S. equorum subsp. equorum grinder et al. 1985
  • S. equorum subsp. linens Place et al. 2003
  • S. hominis subsp. hominis Kloos & Schleifer 1975
  • S. hominis subsp. novobiosepticus Kloos et al. 1998
  • S. saprophyticus subsp. bovis Hájek et al. 1996
  • S. saprophyticus subsp. saprophyticus ( Fairbrother 1940) Shaw et al. 1951
  • S. schleiferi subsp. coagulans Igimi et al. 1990
  • S. schleiferi subsp. schleiferi Freney et al. 1988
  • S. sciuri subsp. carnaticus Kloos et al. 1997
  • S. sciuri subsp. rodentium Kloos et al. 1997
  • S. sciuri subsp. sciuri Kloos et al. 1976
  • S. succinus subsp. casei Place et al. 2003
  • S. succinus subsp. succinus Lambert et al. 1998
745828
de