Difference between revisions of "Category:Bordetella species"

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(Created page with '===Overview=== *''B. bronchiseptica'' infects a wide range of animal species worldwide *''B. avium'' resticted to birds *Normal inhabitants of upper respiratory tract *Cause rep…')
 
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*Slide agglutination tests for virulence of isolates
 
*Slide agglutination tests for virulence of isolates
  
 
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[[Bordetella bronchiseptica]]
===Infectious canine tracheitis/Kennel cough===
 
 
 
*''B. bronchiseptica'' acts as a primary pathogen in [[Respiratory Viral Infections - Pathology#Infectious canine tracheitis|Infectious canine tracheitis]]
 
*Frequently isolated from dogs with respiratory disease
 
*Often found with viruses or mycoplasma
 
*Adheres to ciliated epithelial cells in the trachea
 
*Colonisation and proliferation in trachea
 
*Releases toxins causing epithelial necrosis and prevents ciliary clearance
 
*Irritation to tract causes coughing
 
*Mortality rates low
 
*Peribronchial inflammation and [[Lungs Inflammatory - Pathology#Bronchopneumonia|bronchopneumonia]]
 
can result in unvaccinated puppies or immunosuppressed dogs
 
*Severe pneumonia following secondary infection e.g. with [[streptococci|Streptococci]]
 
*Fatal [[Lungs Inflammatory - Pathology#Bronchopneumonia|bronchopneumonia]] if occurs secondary to [[Paramyxoviridae#Canine distemper virus|canine distemper virus]]
 
*Transmission via respiratory secretions by direct contact or aerosol and on fomites
 
*Clinical signs:
 
**Develop within 3-4 days; persist for up to 2 weeks
 
**Coughing
 
**Gagging
 
**Mild serous oculonasal discharge
 
*Treatments includes antibiotics if coughing persists or bronchopneumonia develops
 
*Live intranasal vaccines
 
*Also found in respiratory tract of cats; can cause pneumonia in kittens; vaccine available
 
 
 
===Atrophic Rhinitis===
 
 
 
*''B. bronchiseptica'' causes [[Nasal Cavity Inflammatory - Pathology#Bacterial rhinitis|Atrophic rhinitis of pigs]] in association with [[Pasteurella species and Mannheimia haemolytica|''Pasteurella multocida'']]
 
*Colonises nasopharynx
 
*Infection must occur during first few weeks of life
 
*Produces dermonecrotic toxin which damages osteoblasts, preventing bone formation
 
*Leads to turbinate atrophy without distortion of the snout in uncomplicated infections
 
*[[Nasal Cavity Inflammatory - Pathology#Bacterial rhinitis|Atrophic rhinitis]] results when [[Pasteurella species and Mannheimia haemolytica|''Pateurella multocida'']] colonises and produces osteolytic toxin, leading to bone resorption
 
*Malformation of snout in growing pigs as well as poor growth
 
*increases with high stocking density and poor ventilation
 
*Vaccine available
 
  
 
===Turkey coryza===
 
===Turkey coryza===

Revision as of 20:58, 10 May 2010

Overview

  • B. bronchiseptica infects a wide range of animal species worldwide
  • B. avium resticted to birds
  • Normal inhabitants of upper respiratory tract
  • Cause repsiratory diseases including rhinitis, tracheitis, bronchitis and bronchiolitis
  • Exogenous or endogenous infection
  • Poor survival in the environment
  • Transmission between animals
  • Young animals particularly susceptible
  • Predisposing factors include stress and concurrent infections
  • High morbidity; low mortality


Characteristics

  • Gram negative rods
  • Strict aerobes
  • Grow slowly
  • Catalase and oxidase positive
  • Non-lactose fermentors
  • Grow on MacConkey agar
  • Toxigenic strains agglutinate mammalian red blood cells
  • Identical S form LPS in all strains of B. bronchiseptica - 1 diagnostic antigen
  • B. bronchiseptica haemolytic, whereas B. avium not
  • Affinity for ciliated respiratory epithelium


Pathogenesis and pathogenicity

  • Use pathogenicity factors such as filamentous haemagglutanin (only B. bronchiseptica), fimbriae and pertactin to adhere to ciliated respiratory epithelium
  • Produce toxins:
    • Adenylate cyclase (leucocyte toxin - kills phagocytes) (only B. bronchiseptica)
    • Tracheal cytotoxin (inhibits DNA synthesis in ciliated cells)
    • Dermonecrotic toxin
  • Pathogenicity factors activated by environment and genetic changes
  • Regulatory locus, BvgAS, mediates the activation
  • Phase variation: genetic switch of Bvg locus allows transciption of pathogenicity factors
  • Phenotypic modulation: temperature, magnesium ions and nicotinic acid affect expression of pathogenicity factors
  • Bvg positive allows expression of pathogenicity factors and toxins and colonisation
  • Bvg negative may allow survival in the environment with production of flagellae
  • Mucosal IgA prevent attachment of bacteria to cilia, but clearance from the respiratory tract may take weeks
  • Carrier animals are a source of infection


Diagnosis

  • Samples include nasal swabs, tracheal aspirates and exudates
  • Cultured on blood agar and MacConkey agar
  • Biochemical profiles
  • Slide agglutination tests for virulence of isolates

Bordetella bronchiseptica

Turkey coryza

  • A highly infectious upper respiratory tract infection of poults caused by B. avium
  • High morbidity, low mortality
  • Infection spread by direct contact, aerosol and from the environment
  • Rhinotracheitis
  • Mucus accumulation in the nares
  • Swelling of maxillary sinuses
  • Beak breathing, lacrimation, sneezing
  • Predisposes to infection with E. coli
  • Treatment with antibiotics
  • Bacterin and modified live vaccines available

Pages in category "Bordetella species"

The following 3 pages are in this category, out of 3 total.