Pasteurellaceae Flashcards
Characteristics
-small gram negative rods
-facultative anaerobes
-biocontainment level 2
includes mannheimia, bibersteinia and pasteurella
mannheimia and bibersteinia
hemolytic
pasteurella
-non-hemolytic
-strong indole smell
-safety pin morphology on gram stain
Pasteurella multocida appearance
-bipolar safety pin morphology
Host or habitats
-part of normal microbiota (oral cavity, resp tract, intestinal tract)
-usually survive poorly outside host but pasteurella multocida can survive for a year in environment in water
Virulence factors of Pasteurella multocida
1.PMT toxin- cytotoxin/leukotoxin
- Capsular polysaccharide- prevents phagocytosis
Virulence factors of Mannheimia haemolytica
- LPS- stimulates cytokine release, microvascular necrosis
- Leukotoxin- kills ruminant leukocytes (specific toxin to cattle)
General categories of disease in the genera
- Respiratory
2.Sepsis - Trauma associated
Pasteurella multocida in cattle
-causes shipping fever (canada), haemorrhagic septicemia (not in canada)
Pasteurella multocida in pigs
-causes atrophic rhinitis
Pasteurella multocida in rabbits
-causes snuffles
Pasteurella multocida in birds
-causes avian cholera
Pasteurella multocida in cats
-causes abscesses
Mannheimia haemolytica in cattle
-causes shipping fever
Bibersteinia trehalosi in ruminants
-causes respiratory disease
Avibacterium paragallinarum in birds
-causes infectious coryza
Lonepinella koalarum in koalas
-can pass to people through bite wounds
Shipping fever
-Acute onset of febrile illness= bronchopneumonia and fibrinous pleuropneumonia
**polymicrobial infections including viruses= bovine respiratory disease complex
What predisposes animals to shipping fever?
-viral infection
-poor air quality
-long distance transport
-weaning (enzootic pneumonia)
Morbidity and fatality of shipping fever
-High morbidity in affected herds (50%)
-high case fatality (5-10%)
**can treat with antimicrobials (macrolide type) and vaccination can prevent disease in feedlots (issue is that farmer pays and feedlot benefits)
Hemorrhagic septicemia in cattle
Acute rapidly fatal septicemia in cattle and buffalo
-fever, dullness, discharge from nose
-edematous swellings in gravity depending sites (cervical and brisket)
-respiratory distress followed by death within 24hrs
Causes of Haemorrhagic septicemia
** seasonal disease- monsoon rains in Asia
-causes by serotypes of P. multocida present in asia and africa
How is haemorrhaic septicemia passed on?
-animals infected through direct contact with carriers/infected or fomites
Treatment of Haemorrhagic septicemia
**not in Canada, only confirmed case on bison in yellowstone National park
Treat:
-antibiotic therapy in early stages
-vaccine possible (commercially prepared, bacterins)
Atrophic rhinitis
-progressive, caused by toxigenic P. multocida type D or A WITH Bordetella bronchiseptica
-transmitted between animals directly
-no magic treatment: management, vaccine, antimicrobials possible
Pathogenesis of P. multocida in pigs
- Bordetella bronchiseptica starts infections and causes damage that allows P. multocida to proliferate
- Toxins produced by multocida cause epithelial hypoplasia, atrophy of mucous glands, osteolysis
- Leads to atrophy of nasal turbinates and shrinking of snouts
Atrophic rhinitis from P. multocida signs
-excessive lacrimation, sneezing, epistaxis
-usually younger pigs have more severe signs
-snout gradually atrophies (shrinks and wrinkles)
P. multocida in rabbits possible presentations
- Rhinitis (snuffles)
- Pneumonia
- conjunctivitis
- otitis media/interna
- abscesses
**clinical signs vary based on site of infection (mild respiratory through sepsis)
Rabbit carriers of Snuffles
-healthy carriers common (30-90%)
-highly contagious, transmitted through direct contact
Avian cholera
-domestic and wild birds
Acute: fulminant septicemia and often sudden death
Chronic: follows acute when caused by less pathogenic strains. Localized infections and swellings of joints and the wattle, AND dyspnea if respiratory involved
Mortality of Avian cholera
Very high! production limiting disease if made onto farm
Avian cholera transmission
-Usually by transmission from excretions from mouth (fluids get into the water and infect others)
-chronically infected birds likely source
-wildlife reservoirs possible so biosecurity on farms important
-isolates from pigs and cats may be pathogenic for birds
Treatment of P. multocida (avian cholera)
**immediately notifiable disease in domestic birds; common in wildlife
-antimicrobials may be used
Pasteurella multocida in cats
Associated with bites, licks, scratches
-abscesses in cats been in fights
-common cause of pyothorax in cats
-may play a role in gingivostomatitis
May be passed to dogs
Treatment: beta lactam/inhibitor (amox +clavulanate)
Pasteurella multocida in humans
Human infections almost always associated with cat bites
-found in 90% of cat mouths
Leads to wound infections, cellulitis, swelling, abscesses, bone and joint infections, resp tract infections, endocarditis, CNS infections
**Treat quickly!
Avibacterium paragallinarum
-Acute upper resp illness in birds causing nasal discharge, sneezing, swelling of face
-production limiting disease (losses due to decreased egg production and increased carcass condemnations
Transmission of Avibacterium paragallinarum
droplets and aerosols from chronically infected birds as source
**use all in and all out biosecurity
Sample collection
-depends on site of infection
>sepsis= spleen, long bones
>respiratory cattle= lung tissue, nasal secretions
>respiratory in pigs and rabbits= exudates, crusts, nasal swabs
>mastitis= milk
>hemorrhagic septicemia= ear tips
>pyothorax/abscesses = aspirates or swabs
NO FREEZING
Lab ID
-Culture easily; use MALDI TOF
-microscopes to ID safety pin morphology
-histopathology- examine biopsy specimens or tissues collected at necropsy
Zoonoses
-Pasteurella multocida- cat bite infections, evidence that it can be shared between species,
Treatment
Depends on host species, site of infection, National disease control strategies (will stamp out certain diseases such as fowl cholera)
Emerging resistance
Emerging resistance among bovine respiratory disease complex pathogens
-resistance to macrolides
tulathromycin, tilmicosin, tildipirosin, gamithromycin
