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**Characteristics:
**Characteristics:
***Formerly known as ''Actinomyces pyogenes'' and ''Corynebacterium pyogenes''
***Formerly known as ''Actinomyces pyogenes'' and ''Corynebacterium pyogenes''
***Small rod
***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
***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
***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
***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
*''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
*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
*Live in nasopharyngeal and oral mucosa
*Cause pyogranulomatous lesions
**''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 yellow sulphur granules
***Club colony formation
***Colonies adhere to agar media and are non-haemoltic
**''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
***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''
*''Actinbaculum suis'' in preputial mucosa of boars
**Found in preputial mucosa of boars
*''Actinobaculum'' have a coryneform morphology
**Anaerobic
**Coryneform morphology
**Produces urease
**Produces lesions in urinary tract of sows
**3mm diameter colonies with shiny raised centre and dull edge
''Nocardia''
''Nocardia''
*Aerobic short branching rods
*Aerobic short branching rods
*Non-motile
*Spores from aerial filaments
*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
*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)
''Dermatophilus congolensis''
*Aerobic
*Motile zoospores
*No growth on Sabouraud dextrose agar
*Found in scabs and in foci on skin of carrier animals