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**Characteristics:
 
**Characteristics:
 
***Formerly known as ''Actinomyces pyogenes'' and ''Corynebacterium pyogenes''
 
***Formerly known as ''Actinomyces pyogenes'' and ''Corynebacterium pyogenes''
***Small rod
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***Small facultatively anaerobic rod
 
***Grows slowly on blood agar to produce small, white colonies surrounded by a zone of beta-haemolysis after 48 hours
 
***Grows slowly on blood agar to produce small, white colonies surrounded by a zone of beta-haemolysis after 48 hours
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***Produces hazy haemolysis after 24 hours; pin-point colonies after 48 hours
 
***Coryneform morphology, like Chinese characters; may be curved with slightly swollen ends
 
***Coryneform morphology, like Chinese characters; may be curved with slightly swollen ends
 
***Found in nasopharyngeal mucosa and genital tract of cattle, sheep, pigs
 
***Found in nasopharyngeal mucosa and genital tract of cattle, sheep, pigs
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***Opportunistic infections following injury or viral/mycoplasma infection in ruminants and pigs
 
***Opportunistic infections following injury or viral/mycoplasma infection in ruminants and pigs
 
***Extracellular toxins including haemolysin, proteases, DNase and neurominidase
 
***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
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***Haemolytic toxin, pyolysin, member of the thiol-activated cytolysins (pore-forming toxins); possibly cytotoxic to phagocytic cells; dermonecrotising activity
 
**Clinical infections:
 
**Clinical infections:
 
***Suppurative infections
 
***Suppurative infections
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*''Actinomyces''
 
*''Actinomyces''
 
*Usually long and filamentous branching Gram positive rods
 
*Usually long and filamentous branching Gram positive rods
**''Actinomyces bovis'' found naturally in oral cavity of cattle; prefers anaerobic conditions but not strict anaerobe; penetrates injured tissues to cause granulomatous lesions of soft tissues and bone, causing lumpy jaw; organisms found in sulphur granules
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*Anaerobic or facultativlyy anaerobic and capnophilic
**''Actinomyces viscosus'' commensal of oral cavity of dogs and humans; causes localised abscesses of skin or granulomatous lesions in thorax which may spread to abdomen causing pyothorax; rods contained in soft grey granules which release the organism when squashed
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*Live in nasopharyngeal and oral mucosa
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*Cause pyogranulomatous lesions
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**''Actinomyces bovis''
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***Found naturally in oral cavity of cattle
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***Prefers anaerobic conditions but not strict anaerobe
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***Penetrates injured tissues to cause granulomatous lesions of soft tissues and bone, causing lumpy jaw
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***Organisms found in yellow sulphur granules
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***Club colony formation
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***Colonies adhere to agar media and are non-haemoltic
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**''Actinomyces viscosus''
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***Commensal of oral cavity of dogs and humans
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***Causes localised abscesses of skin or granulomatous lesions in thorax which may spread to abdomen causing pyothorax
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***Rods contained in soft grey granules which release the organism when squashed
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***Two types of colonies: large and smooth colonies with V, Y and T configurations or small and rough colonies with short branching filaments
   −
 
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*''Actinobaculum suis''
*''Actinbaculum suis'' in preputial mucosa of boars
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**Found in preputial mucosa of boars
*''Actinobaculum'' have a coryneform morphology
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**Anaerobic
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**Coryneform morphology
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**Produces urease
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**Produces lesions in urinary tract of sows
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**3mm diameter colonies with shiny raised centre and dull edge
    
''Nocardia''
 
''Nocardia''
    
*Aerobic short branching rods
 
*Aerobic short branching rods
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*Non-motile
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*Spores from aerial filaments
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*Grow on Sabouraud dextrose agar
 
*Cell wall contains mycolic acids (hence slightly acid fast)
 
*Cell wall contains mycolic acids (hence slightly acid fast)
 
*''Nocardia asteroides'' found in soil
 
*''Nocardia asteroides'' found in soil
 
*Causes granulomatous lesions in animals
 
*Causes granulomatous lesions in animals
 
*Survives and multiplies in macrophages
 
*Survives and multiplies in macrophages
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*Lesions in thoracic cavity, skin and other tissues
 
*Chronic, progressive disease
 
*Chronic, progressive disease
 
*Lesions difficult to treat due to resistance of organisms to many antimicrobials (e.g. penicillins)
 
*Lesions difficult to treat due to resistance of organisms to many antimicrobials (e.g. penicillins)
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''Dermatophilus congolensis''
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*Aerobic
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*Motile zoospores
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*No growth on Sabouraud dextrose agar
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*Found in scabs and in foci on skin of carrier animals
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