List the four infectious predisposing factors for BRDC
Viruses, mycoplasma, bacteria, lungworm
True or false: pneumonia is often caused by a single pathogen/environmental stressor?
False: pneumonia is often a multifactorial disease that is the result of interactions between a complex mixture of pathogens and environmental stressors
List some viral pathogens that can cause bovine respiratory disease
Bovine respiratory syncytial virus (BRSV)
Infectious bocine rhinotracheitis (IBR)
Parainfluenza virus 3 (PI3)
List some mycoplasmas that cause bovine respiratory disease
Mycoplasma bovisMycoplasma dispar
List some bacterial causes of bovine respiratory disease
Pasturella spp., Mannheima spp., Histophilus spp.
List the three individual calf factors that can contribute to bovine respiratory disease
Age, immunity and herd/calf BVDV status
How can you improve the bovine respiratory environment?
Reduce moisture by improving ventilation (introducing 'clean' air and removing 'used' air)
What family do Mannheimia, Pasteurella and Histophilus all belong to?
Pasteurellaceae
Mannheimia, Pasteurella and Histophilus are gram negative/positive bacteria?
Gram negative bacteria
Mannheimia, Pasteurella and Histophilus are motile/non-motile bacteria?
Non-motile bacteria
What is the optimum temperature for growth of Mannheimia, Pasteurella and Histophilus?
37°C
What does LPS and LOS stand for?
Lipopolysaccharide and lipooligosaccharide
What component of bacterial LPS is involved in lung damage?
Lipid A
List some of the toxic effects of LPS
It initiates complement and coagulation cascades
It results in increased vascular permeability and coagulation
It causes accumulation of inflammatory cells, oedema and fibrin deposition in the lungs
True or false: bacteria in the Pasteurellaceae family produce capsids?
True
What type of colonies does Pasteurella multocida form?
Mucoid colonies
What type of agar does Pasteurella multocida grow best on?
Blood agar
Why is Pasteurella multocida isolation from the nasopharynx of little importance?
As it is part of the normal flora of the nasopharynx
List some of the virulence factors of Histophilus somni
Antigenic phase variation of lipooligosaccharide
H. somni produces a weak haemolysin
Outer membrane proteins that bind to the Fc receptor of normal IgG and block binding of specific IgG
Binding nucleotides on the cell surface to enhance survival in or killing of phagocytic cells
Survival in phagocytic cells
Why is H. somni so host specific?
Die to the ability of a species to obtain iron only from a single host
How can we control respiratory disease?
Antibacterials
Vaccinations
Husbandry measures
True or false: there are vaccines available for Mycoplasma species?
