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9 bytes added ,  15:29, 17 February 2008
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*Colonise mucous membranes
 
*Colonise mucous membranes
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*''Arcanobacterium pyogenes''
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**Characteristics:
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===''Arcanobacterium pyogenes''===
***Formerly known as ''Actinomyces pyogenes'' and ''Corynebacterium pyogenes''
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*Characteristics:
***Small facultatively anaerobic rod
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**Formerly known as ''Actinomyces pyogenes'' and ''Corynebacterium pyogenes''
***Grows slowly on blood agar to produce small, white colonies surrounded by a zone of beta-haemolysis after 48 hours
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**Small facultatively anaerobic rod
***Produces hazy haemolysis after 24 hours; pin-point colonies after 48 hours
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**Grows slowly on blood agar to produce small, white colonies surrounded by a zone of beta-haemolysis after 48 hours
***Coryneform morphology, like Chinese characters; may be curved with slightly swollen ends
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**Produces hazy haemolysis after 24 hours; pin-point colonies after 48 hours
***Found in nasopharyngeal mucosa and genital tract of cattle, sheep, pigs
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**Coryneform morphology, like Chinese characters; may be curved with slightly swollen ends
**Pathogenicity''
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**Found in nasopharyngeal mucosa and genital tract of cattle, sheep, pigs
***Opportunistic infections following injury or viral/mycoplasma infection in ruminants and pigs
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*Pathogenicity''
***Extracellular toxins including haemolysin, proteases, DNase and neurominidase
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**Opportunistic infections following injury or viral/mycoplasma infection in ruminants and pigs
***Haemolytic toxin, pyolysin, member of the thiol-activated cytolysins (pore-forming toxins); possibly cytotoxic to phagocytic cells; dermonecrotising activity
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**Extracellular toxins including haemolysin, proteases, DNase and neurominidase
**Clinical infections:
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**Haemolytic toxin, pyolysin, member of the thiol-activated cytolysins (pore-forming toxins); possibly cytotoxic to phagocytic cells; dermonecrotising activity
***Suppurative infections
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*Clinical infections:
***Abscesses especially in liver
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**Suppurative infections
***Pyometra
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**Abscesses especially in liver
***Summer mastitis
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**Pyometra
***Ovine foot disease
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**Summer mastitis
***Umbilical infections
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**Ovine foot disease
***Pneumonia
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**Umbilical infections
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**Pneumonia
*''Actinomyces''
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 +
 
 +
===''Actinomyces''===
 
*Usually long and filamentous branching Gram positive rods
 
*Usually long and filamentous branching Gram positive rods
 
*Anaerobic or facultativlyy anaerobic and capnophilic
 
*Anaerobic or facultativlyy anaerobic and capnophilic
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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
 
***Two types of colonies: large and smooth colonies with V, Y and T configurations or small and rough colonies with short branching filaments
   −
*''Actinobaculum suis''
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===''Actinobaculum suis''===
 
**Found in preputial mucosa of boars
 
**Found in preputial mucosa of boars
 
**Anaerobic
 
**Anaerobic
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**3mm diameter colonies with shiny raised centre and dull edge
 
**3mm diameter colonies with shiny raised centre and dull edge
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''Nocardia''
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===''Nocardia''===
    
*Aerobic short branching rods
 
*Aerobic short branching rods
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*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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===''Dermatophilus congolensis''===
 
*Aerobic  
 
*Aerobic  
 
*Motile zoospores
 
*Motile zoospores
 
*No growth on Sabouraud dextrose agar
 
*No growth on Sabouraud dextrose agar
 
*Found in scabs and in foci on skin of carrier animals
 
*Found in scabs and in foci on skin of carrier animals
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