2,799 bytes removed ,  10:37, 28 July 2011
Replaced content with "Category:Delete Relisted and rewritten by Steph under Infectious Bovine Keratoconjunctivitis as most information was disease related."
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Causes : New Forest Eye Disease
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[[Category:Delete]]
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===Overview===
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Relisted and rewritten by Steph under [[Infectious Bovine Keratoconjunctivitis]] as most information was disease related.
 
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*''Moraxella bovis'' causes infectious bovine keratoconjunctivitis
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*Found on mucous membranes of carrier cattle
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*Susceptible to desiccation therefore short survival in environment
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*Flies act as vectors, in which the bacteria can survive 72 hours
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*Other species non-pathogenic
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===Characteristics===
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*Short, plump Gram negative rods or cocci occuring in pairs
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*Non-motile
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*Aerobic
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*Catalase positive, oxidase postitive
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*Unable to utilise sugars
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*No growth on MacConkey agar
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*Growth enhanced by addition of blood or serum to media
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===Pathogenesis and pathogenicity===
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*Virulent strains have fimbriae, are haemolytic and grow into agar
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*Fimbriae allow adherence to the cornea
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*Q fimbriae are specific for colonisation; I fimbriae allow local persistence of infection
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*Fimbrial antigens stimulate immunity
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*Haemolysin, fibrinolysin, phosphatase, hyaluronidase and aminopeptidase as well as LPS contribute to virulence
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*Haemolysin damages neutrophil membranes; release of hydrolytic enzymes from these [[Neutrophils|neutrophils]] damages the corneal surface
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*Isolates from carrier animals often avirulent, and are non-haemolytic and have no fimbriae; reversion to virulence can occur
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===Clnical infections===
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*Infectious bovine keratoconjunctivitis, or pink-eye/New Forest disease is an ocular disease of cattle
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*Highly contagious infection of superficial tissues of eye
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*Affects animals under 2 years old
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*Decreased weight gain in beef cattle, decreased milk production in dairy herds
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*Age-related immunity due to previous exposure
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*Antibodies against haemolysin neutralise different strains, whereas antibodies to fimbriae are strain-specific
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*Asymptomatic carrier animals harbour the bacteria in the nasolacrimal ducts, nasopharynx and vagina
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*Transmission by direct contact, aerosol and via flies
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*Clinical signs: blepharospasm, conjunctivitis, lacrimation
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*Keratitis and corneal ulceration, opacity and abscessation may lead to panophthalmitis and permanent blindness
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*Stromal oedema; coning of cornea
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*Cornea may heal or undergo permanent scarring
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===Diagnosis===
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*Swabs of lacrimal secretions
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*Fluorescent antibody test demonstrate presence of ''M. bovis''
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*Culture on blood agar; colonies are round, small, shiny and friable
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*Virulent strains surrounded by complete haemolysis and are embedded in the agar
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*No growth on MacConkey
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*Autoagglutination in saline
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*Short Gram negative rods on smears
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*7 serotypes based on fimbriae
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===Treatment and control===
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*Subconjunctival or topical antimicrobials
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*Isolate animals
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*Reduce mechanical irritation such as dust, grass, grass seeds
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*Insect control
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*Control concurrent infections
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*Prophylactic oxytetracycline for animals at risk
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*Vitamin A supplementation
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[[Category:Bacteria miscellaneous]][[Category:Rods]][[Category:Cocci]][[Category:Cattle Bacteria]]
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[[Category:Neurological Diseases - Cattle]]
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[[Category:To Do - Steph]]
 
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