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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…'
===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
===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===
*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 [[Escherichia coli|''E. coli'']]
*Treatment with antibiotics
*Bacterin and modified live vaccines available[[Category:Bacteria]][[Category:Gram_negative_bacteria]]
*''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
===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===
*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 [[Escherichia coli|''E. coli'']]
*Treatment with antibiotics
*Bacterin and modified live vaccines available[[Category:Bacteria]][[Category:Gram_negative_bacteria]]