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Pasteurella species and Mannheimia haemolytica (view source)
Revision as of 11:05, 17 December 2007
, 11:05, 17 December 2007no edit summary
*''P. multocida'' in [[Muscles - inflammatory#Abscesses|cellulitis]] in cats
*''P. multocida'' in [[Muscles - inflammatory#Abscesses|cellulitis]] in cats
===Overview ''Pasteurella''===
===Overview ''Pasteurella'' and ''Mannheimia''===
*Common commensal of the upper respiratory tract and gastrointestinal tract mucosa of animals
*Common commensals of the upper respiratory tract and gastrointestinal tract mucosa of animals
*Usually opportunistic organisms, causing disease during times of stress, low resistance or concurrent infection
*Usually opportunistic organisms, causing disease during times of stress, low resistance or concurrent infection
*Not part of the human bacterial flora
*Not part of the human bacterial flora
*Gram-negative bacilli or coccobacilli
*Facultative anaerobes
*Oxidase-positive
*May show bipolar staining with polychrome stains
*Capsules contain acidic polysaccharides
===''Pasteurella'' Properties===
===''Pasteurella'' Properties===
*Catarrhal odour
*Catarrhal odour
*Produce endotoxins which cause host damage and death
*Produce endotoxins which cause host damage and death
*Resist phagocytosis by their capsule
===''Pasteurella multocida''===
===''Pasteurella multocida''===
*Carried in nasopharynx of many small rodents
*Carried in nasopharynx of many small rodents
*Causes pneumonia in rodents as a secondary disease
*Causes pneumonia in rodents as a secondary disease
===''Pasteurella trehalosi''===
*T biotypes - trehalose fermenters
*Pneumonia in ruminants
*Cause of epizootic pneumonia in cattle known as Shipping Fever, Transit Fever or [[Bacterial infections#Pneumonic pasteurellosis|pneumonic pasteurellosis]]
*Cause of epizootic pneumonia in cattle known as Shipping Fever, Transit Fever or [[Bacterial infections#Pneumonic pasteurellosis|pneumonic pasteurellosis]]
*Usually secondary to viral infections such as [[Viral infections#Parainfluenza- 3|parainfluenza - 3]] or [[Viral infections#In Cattle|IBR]], or to mycoplasma
*Usually secondary to viral infections such as [[Viral infections#Parainfluenza- 3|parainfluenza - 3]] or [[Viral infections#In Cattle|IBR]], bacterial infections such as ''Mycoplasma'' or environmental stress
*Causes pasteurellosis in sheep
*Causes pasteurellosis and mastitis in sheep
*Beta-haemolytic on blood agar
*Beta-haemolytic on blood agar
*Grow weakly on MacConkey agar
*Grow weakly on MacConkey agar
*All are ''Mannheimia'' A biotypes
*All are ''Mannheimia'' A biotypes (previously ''Pasterurella haemolytica''
*Strains often produce a cytotoxin, known as leukotoxin, which kills leukocytes of ruminants
*Strains often produce a cytotoxin, known as leukotoxin, which kills leukocytes of ruminants
*Leukotoxin is a member of the RTX group toxins, and is probably largely responsible for the pathogenicity of the bacteria in septicaemia and pneumonia
*Leukotoxin is a member of the RTX group toxins, and is probably largely responsible for the pathogenicity of the bacteria in septicaemia and pneumonia
*Previously biotype A11
*Previously biotype A11