Moraxella-Avibacterium (Ex2) Flashcards
Moraxella bovis general features
- gram negative pleomorphic rods
- in pairs or short chains
- non-motile
- catalase and oxidase positive
- obligate symbiotic and pathogenic
- resistant in environment
Moraxella bovis virulence factors
- fimbriae (adhesion to host cell)
- capsule
- LPS
- exotoxins: cytotoxin, pore forming toxin
Moraxella bovis disease in bovines
- infectious bovine keratoconjunctivitis
- serous to purulent conjunctivitis and keratitis
- highly infectious
- mainly young animals
Moraxella bovis pathogenesis
- specific attachment of bacteria to conjuncitval/corneal epithelium
- production of toxin: destruction of tissue
- inflammation
- further growth and production of toxins
- increased susceptibility for other pathogens
- non-infectious damage: dust
Moraxella bovis diagnosis
- immunofluorescence
- culture: blood agar
- PCR
Moraxella bovis treatment and prevention
T: antibiotics, corticosteroids, separate stable without flies or dust
P: flies and dust, elimination of predisposing factors, vaccination
Moraxella bovoculi
shape, associated with?
- cocci, diplococci
- associated with keratoconjunctivitis in bovines
Moraxella ovis
shape, associated with?
- cocci
- associated with keratoconjuncitivitis in bovines/sheep, and pneumonia in bovines/sheep
Pasteurella multocida general features
- gram negative
- obligate symbiotic
- little resistance in environment
- capsule types A-E
Pasteurella multocida virulence factors
- adhesions: fimbriae and OMPs
- capsule
- endotoxin: LPS
- iron acquisition: siderophores, OMPs
- toxins: RTX, Rho, Hyaluronidase, Neuramidase
High and Low virulent strains of Pasteurella multocida
symptoms, hosts
Low: rhinitis, pneumonia
- pigs, bovines, rabbits
High: septicemia
- bovines, birds, rabbits
Pasteurella multocida in rabbits
primary symptom, what it can evolve to
- rhinitis (snuffles)
- can evolve to: pleuropneumonia, otitis, conjunctivitis, abscesses
Pasteurella multocida in bovines
- hemorrhagic septicemia
- high mortality (50-100%)
- spread by carriers (tonsils)
- antibiotics do not work
Pasteurella multocida in pigs
- atrophic rhinitis
- lung pasteurellosis: cause by type A
- aerosol transmission
- carriers (nose)
- suppurative bronchopneumonia and fibrinous pleuritis
Pasteurella multocida in poultry
- most susceptible are ducks
- in nose and beaks of healthy animals
- entry: mucosa of mouth, throat, trachea, skin lesions
- septicemia, sneezing, nose excretions, edema head, sudden death
- young adults
Pasteurella multocida in cats and dogs
- licking of wounds
- biting wounds, scratching lesions
- humans infected from bites: local symptoms, swelling of lymph nodes, bacteremia
Mannheimia hemolytica general features
- obligate symbiotic
- capsule types A-F
- low environmental resistance
Mannheimia hemolytica virulence factors
- leukotoxin: RTX family
- transferrin binding proteins
- endotoxins: LPS
- capsule (anti-phagocytosis)
- fimbriae
Leukotoxins of Mannheimia hemolytica
- low dose: oxidative metabolism in NF and MF
- high dose: lysis of phagocytes
- only effective on leukocytes of bovines and sheep
- strongly antigenic
Mannheimia hemolytica in sheep and bovines
Sheep: all serotypes, found in nose, little antimicrobial resistance
Bovine: serotypes 1, 2, 6, found in tonsils and nasopharynx, antimicrobial resistance, bacterial bronchopneumonia in calves
What are the two bacteria involved in shipping fever?
M. hemolytica
P. multocida
Bibersteinia trehalosi
- sheep
- septicemia at 5-12 months
- acute mortality
- stress, changes in feed
Hemophilus general features
- NAD dependent
- obligate symbiotic
- little resistance in environment
- host specific
- age 2 wks to 4 months (weaning)
Symptoms of Hemophilus parasuis
- septicemia: general symptoms, acute mortality
- meningitis: CNS symptoms
- polyserositis, polayarthritis
