Difference between revisions of "Arcanobacterium pyogenes"

Revision as of 16:03, 9 May 2011

Characteristics:
- Formerly known as Actinomyces pyogenes and Corynebacterium pyogenes
- Small facultatively anaerobic rod
- Grows slowly on blood agar to produce small, white colonies surrounded by a zone of beta-haemolysis after 48 hours
- Produces hazy haemolysis after 24 hours; pin-point colonies after 48 hours
- Coryneform morphology, like Chinese characters; may be curved with slightly swollen ends
- Found in nasopharyngeal mucosa and genital tract of cattle, sheep, pigs
Pathogenicity
- Opportunistic infections following injury or viral/mycoplasma infection in ruminants and pigs
- Extracellular toxins including haemolysin, proteases, DNase and neurominidase
- Haemolytic toxin, pyolysin, member of the thiol-activated cytolysins (pore-forming toxins); possibly cytotoxic to phagocytic cells; dermonecrotising activity
Clinical infections:
- Suppurative infections
- Abscesses especially in liver
- Lymphadenitis, osteomyelitis, peritonitis and neural abscessation
- Pyometra
- Endometritis
- Summer mastitis
- Ovine foot disease
- Arthritis of sheep post-dipping; arthritis in pigs and arthritis in cattle
- Umbilical infections
- Acute exudative pneumonia and contributes to Enzootic pneumonia of calves
- May cause myositis
- Unclassified Actinomyces species isolated from closed cases of Poll Evil and Fistulous Withers
Treatment:
- Penicillin or broad spectrum antibiotics

Formerly known as Actinomyces pyogenes and Corynebacterium pyogenes
Small facultatively anaerobic rod
Grows slowly on blood agar to produce small, white colonies surrounded by a zone of beta-haemolysis after 48 hours
Produces hazy haemolysis after 24 hours; pin-point colonies after 48 hours
Coryneform morphology, like Chinese characters; may be curved with slightly swollen ends
Found in nasopharyngeal mucosa and genital tract of cattle, sheep, pigs

Opportunistic infections following injury or viral/mycoplasma infection in ruminants and pigs
Extracellular toxins including haemolysin, proteases, DNase and neurominidase
Haemolytic toxin, pyolysin, member of the thiol-activated cytolysins (pore-forming toxins); possibly cytotoxic to phagocytic cells; dermonecrotising activity

- Cause purulent arthritis
- In one or more joints
- Commonly contaminate wounds

Infections at any age:
- Corynebacterium pyogenes
  - Suppurative arthrtis
  - Often due to pebetrating wound into or close to joints

@@ Line 1: / Line 1: @@
-New name: '''''Trueperella pyogenes'''''
 *Characteristics:
 **Formerly known as ''Actinomyces pyogenes'' and ''Corynebacterium pyogenes''