Lecture 17 - Respiratory Bacteriology 2 Flashcards
describe the morphology of Bordetella
gram-negative, coccobacilli, strict aerobe, motile
T/F: bordetella is typically commensal until a phase change
TRUE
what is the virulence control system for bordetella
BvdAS gene
how does bordetella attach to host cells
Filamentous haemagglutinin acts as a protein for attachment to ciliated epithelial cells
describe the pathogenesis of bordetella in 5 steps
- environmental change (temp, resp. epithelial damage)
- activation of BvdAS locus
- FHA and toxin production
4a. tissue death and immune modulation
4b. ciliostasis and destruction of clearance - respiratory tract inflammation
what are the predisposing factors for bordetella
- young animals
- primary or co- infection
- chemical fumes/smoke damage lungs
a swine farmer calls you regarding suckling pigs that have s+ and nasal discharge. Sows have malformations of the nose and decreased growth at adulthood
necropsy reveals turbinate atrophy and deviation of septum. what is the diagnosis?
atrophic rhinitis
what is atrophic rhinitis
co-infection between B. bronchiseptica and P. multocida type d
what is the effect of toxins produced by P. multocida
disruption of oncogenesis and stimulated bone resorption of nasal turbinates
what predisposes swine to atrophic rhinitis
- high dust environment
- poor ventilation
a client from south dakota brings you an unvaccinated dog from an Indian reserve. the dog has a fever, discharge, v+/d+/c+, and dyspnea which has progressed to neurologic signs.
the necropsy reveals interstitial pneumonia and exudate in airways. microscopy reveals neutrophils and viral inclusion bodies. what is the diagnosis
bordetella and canine distemper
T/F: canine infectious respiratory disease complex (CIRD)/kennel cough is generally self-limiting
TRUE
a 36 d/o turkey poult is submitted for postmortem exam after c+ and swollen sinuses.
tracheal collapse is present and cilia-associated bacteria are present on histopathology. what bacteria will be cultured?
bordetella bronchiseptica
describe the morphology of Moraxella
gram-negative rods, aerobic, non-motile
how does Moraxella adhere to the cornea
fimbriae
describe the action of RTX cytotoxin
lysis of corneal epithelial cells and neutrophils
T/F: avirulent strains of Moraxella lack either cytotoxins or fimbriae
TRUE
describe Moraxella
common name?
risk factor?
transmission?
common: “pink eye”, IBK
risk factor: animal <2 y/o
transmission: direct contact, aerosol, vector
samples for Moraxella should be taken from where
laminal secretions
what are the 3 ways Moraxella is treated/controlled
- antimicrobials
- vaccine
- management - fly control, isolation, reduced irritant exposure
The Pastuerellaceae family has what RNA sequence
16S rRNA
Pasteurella is considered both ____ and ____
commensal and opportunistic
describe P. multocida
gram-negative, rod to cocci, non-motile, facultative anaerobe
capsule type A and B of Pasteurella are made of
hyaluronic acid
capsule type D of Pasteurella is made of
heparin
capsule type F of Pasteurella is made of
chondroitin
what is the somatic typing of Pasteurella
16 somatic serotypes divided by O antigen
describe the adhesion, replication, and toxin production of P. multocida
adhesion: fimbriae, FHA
replication: iron-dependent, type a capsule predominant
toxin production: type D PMT
T/F: it is unknown the mechanism that contributes to virulence differences among P. multocida strains
TRUE
what are the 3 disease forms of P. multocida
- resp. - pneumonia, pleuropneumonia, URT
- septicemia - B and E serotypes
- skin wound - trauma associated
what are risk factors for P. multocida
- young
- stress
- immunosuppression
- co-infection
- primary viral infection
describe pasteurellosis in rabbits
*snuffles
associated w type A
purulent rhinitis
50 w/o broiler breeder spike males are submitted to necropsy for swollen necrotic waddles, fibrinous synovitis/airsaculitis/pneumonia, and heavy fowl mite infestation
histology reveals airways with exudate and bacterial colonization. what is your diagnosis
septicemia pasteurellosis
T/F: Young birds are more resistant to fowl cholera
TRUE
what are the acute and chronic phases of fowl cholera characterized by
acute = sudden death due to hemorrhage
chronic = reduced production
what antibiotics are P. multocida susceptible to
penicillin and tetracycline
is P. multocida vaccinated for
yes - killed/MLV for poultry and ruminants, toxoid for swine
describe mannheimia haemolytica
gram-negative, rod, non-motile, facultative anaerobe
what grows of MacConkey agar:
M. haemolytica or P. multocida
M. haemolytica although both are gram-negative
describe the 3 steps of M. haemolytica pathogenesis
- adhere
- replicate
- toxin damage
what toxin is produced by M. haemolytica
leukotoxin
describe bibersteinia trehalosi
gram-negative, rod, non-motile, facultative anaerobe
what are the 3 disease manifestations of Bibersteinia trehalosi
- bronchopneumonia
- septicemic pasteurellosis
- mastitis
what are the special growth requirements for Haemophilus
- hemin (factor X)
- nicotinamide adenine dinucleotide (NAD/Factor V)
What else would you need if you wanted to grow Haemophilus on blood agar?
Staphylococcus aureus nurse
describe the disease caused by Glasesserella parasuis
commensal in pigs, requires NAD/factor V to grow
causes glasses disease - bronchopneumonia + polyserositis/meningitis/arthritis
how is G. parasuis treated
penicillin, tetra, tiamulin or vax
describe the disease caused by avibacterium paragallinarum
chickens; requires factor V to grow
infectious coryza characterized by facial swelling, S+ with discharge
T/F: depop, cleaning, and vax are treatments for A. paragallinarum
TRUE
describe Histophilus somni
commensal in bovine
causes bronchopneumonia +/- speticemia
what are the benefits of the endotoxin produced by H. somni
Lipooligosaccharide (LOS) helps initiate antigenic shift which evades the immune system
resistant to complement-mediated lysis
T/F: vaccines for H. somni are safe and effective
FALSE - IgG protective for systemic infections, but not respiratory and adverse effects have been reported
describe actinobacillus
gram-negative, rod, non-motile
commensal in mares
what is the primary respiratory pathogen for pigs
Actinobacillus pleuropneumoniae
what exotoxin is produced by A. pleuropneumoniae
Apx toxin I-IV (resulting in cell lysis and tissue damage)
15 w/o finishing pigs are brought to necropsy upon sudden death with history of respiratory issues.
necropsy reveals multifocal pulmonary hemorrhage and consolidation with fibrin. PCR is negative for PCV2 and ASFV. what is your diagnosis
A. suis
how are carriers of APP identified
- tonsilar scraping in sows
- serological screening
how do actinobacillus spp. differ
A. pleuropneumonia - classic lesions, only lung changes at death
A. suis - common lesion but more disease processes (inflammation)
A. equuli - more common in foal, acute bacterial sepsis and endocarditis in pigs
T/F: MALDI-TOF testing can confirm ID from contaminated samples
FALSE - need pure isolates
what two bacterial species need a nurse streak of Staph aureus
- glaesserella
- actinobacillus
