Actinobacillus

Actinobacillus spp. are bacteria belonging to the family Pasteurellaceae (this further includes, for example, genera Haemophilus a Pasteurella).

Morphology
It is about gram-negative, facultatively anaerobic immobile and non-sporulating rods of pleomorphic shape, sometimes referred to as stick-like. They are often protected by a case. They can occur as sticks or coca. In media with a higher content of glucose or maltose they form fibers.

Cultivation
Actinobacillus is cultivation demanding bacteria, we inoculate it on chocolate or blood agar in an atmosphere with 5% CO2. On solid media tt forms star-shaped colonies which grow into agar, in broths we observe growth in small granules.

Occurrence
Actinobacillus spp. we find as commensal and parasitic flora mucosal tissue surfaces in humans and animals.

Clinically significant are Actinobacillus ureae and Actinobacillus hominis, which are found only in humans and can be the etiological cause of airway inflammation. Other species like Actinobacillus equuli, Actinobacillus lingieresii or Actinobacillus suis are animal pathogens that can be transmitted to humans by biting and then cause purulent infections of these wounds.

Previously Actinobacillus actinomycetemcomitans was also included in this genus, however today is ranked among the hemophiles (Haemophilus actinomycetemcomitans).

Therapy
Except penicillin, for treatment can be used most of beta-lactam antibiotics or aminoglycosides or fluoroquinolones.