bacteriology pasteurellaceae Flashcards
Pasteurellaceae morphology and shared features
short, squished looking rods
gr -
facultative anaerobic
oxidase + (good for differentiating from enterobacterales)
most are non motile (enterobacterales are motile)
grow on blood agar (except Histophilus, Glaeserella, Avibacterium need additional growth factors e.g., in “chocolate” agar)
Variable growth on MacConkey’s agar even though gram negative rods
pasteurella
pasteurellaceae order
Gram negative rods (short)
Bipolar staining in Giemsa/Diff Quik
Facultatively anaerobic
Oxidase positive
Non-motile
where do pasturellaceae come from?
Most are normal flora of mucus membranes of animals and birds:
Upper respiratory tract (nasal cavity and nasopharynx)
* P. multocida, M. haemolytica, Actinobacillus spp., G. parasuis, H. somni
Some are only present on the mucus membranes of carrier animals and birds:
* Upper respiratory tract (nasal cavity and nasopharynx)
* Some more pathogenic strains of P. multocida, Actinobacillus, pleuropneumoniae, Avibacterium paragallinarum
None survive in the environment for a long time
Digestive tract
* P. multocida (mouth only), Actinobacillus spp.
Lower genital tract
* Actinobacillus suis and H. somni
how are pasteurellaceae transmitted?
Most infections caused by the Pasteurellaceae occur in sites NEAR where these bacteria occur as part of the normal flora
Therefore transmission is by:
* Inhalation
* Direct inoculation either locally or systemically
How do pasteurellaceae cause dz?
Just like other Gram negative pathogens!
Attachment: Fimbriae (Pili) or Adhesins
Avoidance of phagocytosis: Capsule
Cellular toxicity: Exotoxins
Local & Systemic Effects: Endotoxin
pathogenesis of pasteurellaceae
present as normal flora on mucous membranes of animal and birds they require some change in the host (either internal or due to external factors) to be able to cause infections
→ OPPORTUNISTIC INFECTIONS
risk factors for pasteurellaceae infections
Risk Factors for (respiratory) infections include:
* Age (young)
* Co-mingling
* Crowding or Indoors
* Other infections (1º viral)
* Poor weather
pasteurellaceae strains not involved in normal flora
“better” pathogens
Fowl Cholera
* P. multocida capsule type A
Bovine Hemorrhagic Septicemia
* P. multocida capsule types B and E
on carrier animals
Pasteurella multocida causes what diseases
Pneumonia
Rhinitis
Bite wounds infection
Septicemia
pneumonia caused by pasteurella
Most important disease caused by Pasteurella multocida
Causes pneumonia in a wide range of animal species
* Bovine Respiratory Disease Complex or Shipping Fever
* Particular economic importance in ruminants
* Severe, fibrinous, hemorrhagic, lobar pneumonia
* Fibrinopurulent exudate in airways
predisposed by shipping stressed
rhinitis and pasteurella
pasteurella multocida
Respiratory disease is also a big problem in Rabbits
“Snuffles” (rhinitis); most common form of disease and usually mild
Develop mucopurulent discharge that occludes nares and conjunctiva
Pneumonia with fever, nasal discharge and respiratory distress can develop
Less common – septicemia
Atrophic Rhinitis and pasteurella
pasteurella multocida
Disease of young pigs (3-7 weeks)
Due to combined effects of two bacteria:
* Bordatella bronchiseptica causes the initial damage to nasal mucosa and allows invasion by P. multocida
* P. multocida type D have a dermonecrotic toxin that causes causes bone resorption of bony turbinates and suppresses osteoid synthesis adjacent to inflamed area
clinically:
* Sneezing
* Epistaxis
* Facial distortion
pasteurella and wound infections
pasteurella multocida
Predominantly bite wounds or licking open wounds
* Oral flora (mixed infections)
* Pasteurella + strict anaerobes
Cat bites more commonly infected than dog bites
Type of wounds and skin of cats
Strains of Pasteurella in cat’s mouths
septicemia and pasteurella
pasteurella multocida
NOT normal flora strains, not in USA
causes Bovine Hemorrhagic Septicemia
also causes in poutlry
What diseases does Mannheimia haemolytica cause?
pasteurellaceae
Pneumonia/bronchopneumonia
* “Shipping Fever” in cattle +/- P. multocida
* Enzootic Pneumonia in sheep + goats (only M. haemolytica – not P. multocida)
Necrotizing mastitis
* In ewes (“blue bag”) – lambs give M. haemolytica to ewes when suckling
* Damage due to leucotoxin - necrotizing
Septicemia
* In lambs
actinobacillus equuli causes what diseases?
pasteurellaceae
Predominantly a pathogen of horses (also pigs, calves etc) and causes:
* “Sleepy Foal Disease”
* Septicemia in neonatal foals
* Localizatio* in other sites (e.g. kidney)
* Peritonitis in adult horses
* Pneumonia and Pleuropneumonia
* Streptococcus spp +/- Pasteurella spp +/- NSFA
