Pasteurella & Mannheimia Flashcards
What are the 2 main structural characteristics of Pasteurella? What fermentation does it undergo?
- Gram-negative coccobacilli
- stains bipolar with Wright or Giemsa stain
ferment sugar without gas —> TSI turns orange
Where do all Pasteurella colonize? What is one exception?
respiratory tract
P. aerogenes —> GI tract
How does Pasteurella multocida grow on media? How does it respond to the indole test?
prefers blood agar, will NOT grow on MacConkey, and has a mousy odor
indole +
What colony types of Pasteurella multocida are encapsulated and virulent?
mucoid and smooth types
(there is also a rough type)
How does Pasteurella multocida infection compare to Haemophilus?
not as host-specific —> infections occur in many animals and humans
What specific diseases is Pasteurella multocida responsible for in poultry, cattle/sheep, swine, rabbits, cats/dogs, and humans? Does it have zoonotic potential?
POULTRY: fowl cholera
CATTLE/SHEEP: hemorrhagic septicemia, pneumonia (BRD), mastitis
SWINE: atrophic rhinitis, pneumonia
RABBITS: snuffles, pneumonia, septicemia
CATS/DOGS: local infections, bite wounds, respiratory infection
HUMANS: bite wounds, systemic infections
YES
How is Pasteurella multocida transmitted?
primarily carried in oral cavity and respiratory tract —> contact, direct inoculation (bite, scratches), aerosol, water (fowl cholera), endogenous
What is the 3 steps to the pathogenesis of Pasteurella multocida?
- part of the normal flora of the upper respiratory tract of man mammals
- presents as a pathogen in birds (NOT part of the flora), but those that recover act as a carrier and spread
- infections occur following stress
What causes fowl cholera? What is specifically not produced by this agent?
Pasteurella multocida types A1, A3, and A4, which contain hyaluronic acid in their capsule, a normal component of host tissue
A serotypes do not produce exotoxins
What animals are affected by fowl cholera? What are the common clinical signs? What does chronic infection lead to?
chickens, turkeys, ducks, geese, and other wild birds
- overwhelming bacteremia/septicemia
- depression
- inappetence
- diarrhea
- biofilm formation in the air sacs and mucous membranes, making them more difficult to clear
What is the relationship between Pasteurella multocida and birds?
frank pathogen, NOT an opportunistic pathogen
Fowl cholera:
- swollen wattles
- depression
- cellulitis
What is commonly seen within the swollen wattles of chickens with fowl cholera?
purulent material containing bacteria in biofilms
Fowl cholera, turkey:
- blood-stained mucus in mouth of septicemic tukey
- young, acute
Fowl cholera, septicemic form:
peritonitis
Fowl cholera, 10-week-old turkey:
- purulent pleuropneumonia
- pulmonary edema
Fowl cholera, turkey lungs:
- very consolidated pneumonia
- firm and not spongy, filled with bacteria and neutrophils
Fowl cholera, spongy bone:
- inflammation of air spaces within spongy bone of the skull
- purulent exudate
- swollen head syndrome
What is the predominant clinical sign of fowl cholera affecting the hock joint?
lameness
- purulent synovitis
What causes hemorrhagic septicemia? What animals are typically affected?
Pasteurella multocida B2 (Asia) and E2 (Africa)
exotic disease of cattle, buffalo, sheep, and goats
What are the 5 clinical signs of hemorrhagic septicemia? What causes disease?
- blood in cavities
- enteritis
- edema
- septicemia
- pneumonia
Pasteurella multocida B2 and E2 produce exotoxins
What causes Shipping Fever (bovine respiratory disease complex)? What animals are commonly affected?
Pasterurella multocida A strains
cattle, goats, sheep (opportunistic!)
What is Shipping Fever commonly secondary to? What are 4 common clinical signs?
stress or viral/mycoplasma infection
- cough
- fever
- nasal discharge
- bronchopneumonia
Shipping Fever (BRD complex) is a polymicrobial disease. What are 3 other possible agents?
- Mannheimia haemolytica
- Histophilus somni
- Mycoplasma bovis
- also: BHV-1, bovine diarrhea virus, bovine respiratory syncytial virus, parainfluenza-3
What is the main cause of atrophic rhinitis? How? What other pathogen does it typically present with?
Pasteurella multocida type D strains that produce dermonecrotoxin that causes bone resorption of turbinates and conchal bones and suppresses osteoid synthesis —> atrophied and deviated snout, difficulty breathing and eating
Bordetella bronchiseptica