Respiratory pathogens 1 (tesse) Flashcards
Where is the ciliated epithelium in the resp tract
nasal epithelium
bronchi
trachea
pharynx (?)
what is the function of the ciliated epithelium
muco-ciliary apparatus
What are the three bacteria with tropism for the ciliated epithelium
Bordetella
Mycoplasma
Chlamydia
What are the three routes of infection into the respiratory tract
aerosol
particle/droplet
conjuctival
what determines the severity, type and location of respiratory infection
bacterial virulence factors
what are the types of respiratory infections
pharyngitis/laryngitis
tracheitis
bronchitis
pneumonia
etc
what virulence factors are responsible for Adherence and resistance to expulsion:
- Pili (Fimbriae)
- Adhesins
- Biofilm
what virulence factors are responsible for Survival in infected cells:
- Ability to compete for iron
- Survival in phagosomes
what virulence factors are responsible for Invasion of host cells:
- Adhesins type Invasins
- Interaction with cytoskeleton to promote
engulfment - M-protein for Streptococcus
what virulence factors are responsible for Disease production/damage host:
- Super antigens
- Cell wall components
What are the main resp pathogens of cattle
Mannheimia haemolytica
Pasteurella multocida
Bibersteinia trehalosi
Histophilus somni
Mycoplasma bovis
Mycobacterium bovis
what is shipping fever
combination of primary or secondary bacterial pathogens with primary or secondary viral pathogens and stress
(virus + bacteria + stress)
etiology of Mannheimia haemolytica
- Gram-negative, pleomorphic rod/coccobacilli
- Related to Pasteurella (formerly Pasteurella haemolytica)
- Fastidious
Mannheimia haemolytica is commensal to the
oropharynx
_____ predisposes the host to pneumonic pasteurellosis
Mycoplasma
Mycoplasma predisposes the host to _______
pneumonic pasteurellosis
what is vx against Mannheimia haemolytica based on
the 17 serotypes based on capsular suface antigens
Mannheimia haemolytica virulence factors
Leukotoxin – induces lysis of leukocytes and platelets
* Capsular polysaccharide (CPS) – prevents phagocytosis
* Lipopolysaccharide (LPS) – Stimulates cytokine releases and microvascular necrosis
Mannheimia haemolytica Pathogenesis
Viral infections/environmental stressors lead to shift in the mucosal-commensal
relationship leading to colonization of the organism → Spread to other animals
- Animals that inhale fomites or infective droplets → bacteria deposit in the mucous layer of the mucociliary apparatus → toxins lead to mucociliary dysfunction → pneumonia
Mannheimia haemolytica lesions
Hemorrhagic fibrinonecrotic bronchopneumonia
* Septicemia – fibrinous pleuritis, pericarditis and peritonitis
Histophilus somni etiology
Gram-negative, pleomorphic rod
* Fastidious – capnophilic → requires CO2
for growth!
Where does H. somni colonize
mucosal surfaces
H. somni pathogenesis
Adheres to endothelial cells → induces cytotoxic changes, vasculitis and induction of
apoptosis → formation of fibrinoid thrombi
What are some of the organ systems of cattle affected by H.somni
pleuritis +/- bronchopneumonia
myocarditis (causing sudden death)
thrombotic meningoencephalitis
arthritis