Actinomyces
Actinomyces israelii
- A. bovis
- A. bowdenii
- A. canis
- A. cardiffensis
- A. Catuli
- A. coleocanis
- A. dentalis
- A. denticolens
- A. europaeus
- A. funkei
- A. georgiae
- A. gerencseriae
- A. graevenitzii
- A. hongkongensis
- A. hordeovulneris
- A. howellii
- A. humiferus
- A. hyovaginalis
- A. israelii
- A. marimammalium
- A. meyeri
- A. naeslundii
- A. nasicola
- A. neuii
- A. odontolyticus
- A. Oricola
- A. radicidentis
- A. radingae
- A. slackii
- A. streptomycini
- A. suimastitidis
- A. suis
- A. turicensis
- A. urogenital
- A. vaccimaxillae
- A. viscosus
Actinomyces is a bacterial genus of the family Actinomycetaceae. Characteristic of these bacteria are elongated, often branched cells without active movement, predominantly anaerobic growth and positive behavior in the Gram stain.
Shape, cell structure
In general, straight or curved rod-shaped cells with a diameter of 0.2-3.0 microns. The length is very different, most individuals are long- ply up to a length of 50 microns or even more. Some species form small, branched mycelia. The langfädigen shapes and mycelia proliferate occasionally decay into short cells ( segmentation ). Endospores are not formed. Gram- positive behavior. No active movement.
Metabolism
Actinomyces species are predominantly anaerobic, facultatively aerobic, some are only a few possess the enzyme catalase. (HCO3-) concentration in the culture medium allows growth under aerobic conditions or bicarbonate - In some species, is caused by a high carbon dioxide (CO2). Most species need to grow a complex nutrient supply. Often they have a fermentative energy metabolism, are reacted at the carbohydrates into organic acids.
Occurrence of life
Most species occur in warm-blooded vertebrates, either as pathogens or as commensals. Therefore, the optimum temperature of growth is relatively high: 30-37 ° C. The pathogens, in particular A. israelii, causing various diseases ( Aktinomykosen ), particularly abscesses in the oral cavity, lungs (see Farmer's lung, " farmers ment " ) and in the gastrointestinal tract.
Origin of the name
Particular attention was paid in the 19th century by Actinomyces species induced bulbous concretions in various affected body parts of animals. In cross- section through this time based on an expression of Mineralogy so-called " drusen " shows a radiating structure, which is caused by strahliges from a point emanating hyphae growth of the bacteria. There were thought to be fungi at the time bacteria of the genus Actinomyces as well as other myzelbildende bacteria ( such as those of the genus Streptomyces ), they were given the German name " ray fungi "; in biology was the appropriate term " Actinomycetes " (or " actinomycetes " ), formed from ancient Greek ακτίς - aktis = beam and μύκης - mykes = fungus. The German botanist Carl Otto resin called 1877 the causative agent of such a concretion in a bovine Actinomyces bovis.