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Redirected page to Category:Actinomycetes
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−<big><center>[[Infectious agents and parasites|'''BACK TO INFECTIOUS AGENTS AND PARASITES''']]</center></big>+<big><center>[[Bacteria|'''BACK TO BACTERIA''']]</center></big>
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−*Cause [[Peritoneal cavity - inflammatory#In dogs|peritonitis in dogs]] and [[Peritoneal cavity - inflammatory#In cattle|peritonitis in cattle]] and [[Peritoneal cavity - inflammatory#In pigs|peritonitis in pigs]]
−*''Micropolyspora faeni and Thermactinomyces vulgaris'' in [[Bronchi and bronchioles - inflammatory#Extrinsic Allergic Bronchio-alveolitis|Bovine Farmers Lung]]
−*''Thermactinomyces vulgaris'' may cause [[Bronchi and bronchioles - inflammatory#Chronic obstructive pulmonary disease (COPD)|COPD]]
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−===Overview===
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−*Gram positive bacteria
−*Grow slowly on media and produce branching filaments
−*Opportunistic infections causing inflammatory responses and granulomatous reactions
−*Animal pathogens include ''Actinomyces, Arcanobacterium, Actinobaculum, Nocardia'' and ''Dermatophilus''
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−===''Arcanobacterium, Actinomyces'' and ''Actinobaculum'' species===
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−*Non-motile, non-spore-forming bacteria
−*Anaerobic or facultative anaerobes
−*Grow on enriched media; non-acid fast
−*Colonise mucous membranes
−*Modified Ziehl-Neelson negative
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−===''Arcanobacterium pyogenes''===
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−*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, [[Bones - inflammatory#Osteomyelitis|osteomyelitis]], peritonitis and neural abscessation
−**Pyometra
−**Endometritis
−**Summer mastitis
−**Ovine foot disease
−**Arthritis
−**Umbilical infections
−**Suppurative pneumonia
−*Treatment:
−**Penicillin or broad spectrum antibiotics
−**Unclassified ''Actinomyces'' species isolated from closed cases of [[Bursae and Tendons - inflammatory#Poll Evil and Fistulous Withers|Poll Evil and Fistulous Withers]]
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−===''Actinomyces''===
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−*Usually long filamentous branching Gram positive rods
−*Anaerobic or facultativlyy anaerobic and capnophilic
−*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 [[General Pathology - Chronic Inflammation#Granulomatous Inflammation|granulomatous inflammation]] lesions of soft tissues and bone, causing [[Oral Cavity - Teeth#Mandibular Osteomyelitis|lumpy jaw]]
−***Usually invades mandible to cause [[Bones - inflammatory#Osteomyelitis|osteomyelitis]] and may extend to surrounding [[Muscles - inflammatory#Actinomycosis bovis|muscles]]
−***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
−***Canine actinomycosis
−***Causes localised subcutaneous pyogranulomatous lesions and fibrovascular proliferation of peritoneal and pleural surfaces in dogs
−***Leads to [[Pleural cavity and membranes - inflammatory#Pyothorax (Thoracic empyema)|pyothorax]]
−***Respiratory distress
−***Cutaneous pustules in horses
−***Abortion in cattle
−***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
−***Grow in 10% carbon dioxide
−***Usually responds to penicillin
−**''Actinomyces hordeovulneris''
−***Organism found in seed heads of certain grasses
−***Colonies adhere to agar and are non-haemolytic
−***Filamentous, branching organisms
−***Cause cutaneous and visceral abscessation, pleuritis, peritonitis and arthritis in dogs
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−===''Actinobaculum suis''===
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−**Found in preputial mucosa of boars
−**Anaerobic
−**Coryneform morphology
−**Produces urease
−**3mm diameter colonies with shiny raised centre and dull edge
−**Produces lesions in urinary tract of sows
−**Cystitis and pyelonephritis in sows
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−===''Nocardia''===
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−*Aerobic short branching rods
−*Non-motile
−*Spores from aerial filaments
−*Grow on Sabouraud dextrose agar
−*Cell wall contains mycolic acids (hence slightly acid fast)
−*''Nocardia asteroides'' found in soil
−*Causes granulomatous lesions in animals
−*Involved in [[Peritoneal cavity - inflammatory#In dogs|peritonitis]] and [[Bacterial infections#Nocardiosis|pleuritis]] in dogs
−*Survives and multiplies in macrophages
−*Lesions in thoracic cavity, skin and other tissues
−*Chronic, progressive disease
−*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
−*Motile zoospores
−*No growth on Sabouraud dextrose agar
−*Found in scabs and in foci on skin of carrier animals
#REDIRECT[[:Category:Actinomycetes]]
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