Mycobacteria Flashcards
what are the general characteristics of Mycobacteria? (aerobic status, shape, spores?, gram/acid?, heat sensitivity?)
obligate aerobes
bacilli
non-spore forming
acid-fast bacteria
heat sensitive
why does Mycobacterium not take up gram stain dyes?
high concentration of mycolic acids and lipids
what is an effective way to kill Mycobacterium?
pasteurization b/c bacteria is heat sensitive
How long does it take for pathogenic mycobacterium to grow?
3-6w
what stain is used to differentiate mycobacteria from other bacteria?
Ziehl-Neelsen
Are there few or many mycobacterium species?
many many many
How is mycobacterium transmitted?
inhaled and ingested
List the clinically relevant veterinary mycobacterial series?
bovine tuberculosis, Johne’s disease, poultry tuberculosis, feline leprosy
what is the causative agent of bovine tuberculosis?
Mycobacterium bovis
what are the main concerns with bovine tuberculosis?
causes production loss
difficult to control due to wildlife reservoirs
human to cattle infection possible
Why are the cases of Bovine tuberculosis low in the US compared to earlier times?
eradication programs
Is bovine tuberculosis zoonotic?
yes
How is Bovine tuberculosis transmitted?
through aerosols, ingesting contaminated milk
what are the wildlife reservoirs for bovine tuberculosis?
badgers, deer, elk, feral pigs
Describe the pathogenesis of Bovine tuberculosis
what happens when Mycobacterium bovis is taken up by alveolar macrophages vs dendritic cells? (end result)
alveolar macrophages - granuloma formation, bacteria contained
dendritic cells - lymphatic tuberculosis
Which mycobacterium species can spread from humans to dogs?
Mycobacterium tuberculosis
What causes the necrotic and caseous lesions seen with bovine tuberculosis?
lytic enzymes released by activated macrophages
Explained how Bovine tuberculosis that is cleared or latent can be reactivated
granulomas contain infection > no signs of disease > bacteria survive inside granuloma > bacteria reemerge and cause disease
what are granulomas in tuberculosis called?
tubercles
what are the arrows pointing at on these animals?
tubercles
When are the clinical signs seen with bovine tuberculosis?
only evident in advanced disease