Lecture 19 - Respiratory Bacteriology 4 Flashcards
describe mycobacterium morphology
aerobic, rods, acid-fast positive (red)
does mycobacterium cause acute or chronic disease
chronic
where do mycobacterium live once in the body
macrophages
what is caused by the strong cell-mediated immune response to mycobacterium
type IV hypersensitivity and formation of granulomatous inflammation
what allows mycobacterium to survive in macrophages
- cord factor (TMD)
- sulfur-containing glycolipids
- more lipid content
what are the 3 chronic progressive diseases caused by mycobacterium
- tuberculosis
- leprosy
- Johne’s disease
how is mycobacterium diagnosed
- intradermal skin (tuberculin) test
- culture
- PCR
- acid-fast stain
describe mycobacterium tuberculosis
main causative agent of human TB that mainly targets the lung
why might someone without TB test positive
vaccine history
describe mycobacterium bovis
Bovine TB
*reportable
*zoonotic
what are the 3 main layers of tubercle formation in Mycobacterium bovis
- central necrosis
- multinucleated giant cells, macrophages, intracellular organisms
- encapsulated fibrous CT
describe Burkholderia
gram - rod found in soil/water/rodents
what does Burkholderia cause
“glanders” in equine
what mycobacterium diseases are reportable
- Burkholderia
- Mycobacterium Bovis
where is glanders endemic? is it zoonotic?
middle east, india, china
zoonotic
what causes pseudoglanders
burkholderia pseudomallei
*also known as melioidosis
T/F: burkholderia pseudomallei forms abscesses in multiple organs
TRUE
what are the two filamentous bacteria
- actinomyces
- nocardia
describe the morphology of nocardia
gram +, rod to filamentous, acid-fast bacteria
what is the most common spp. for nocardia
N. asteroides
T/F: nocardia spp. tends to be associated with severe infections
FALSE
how does infection occur with N. asteriodes
opportunistic through ingestion, inhalation, and wounds
in cats and dogs, N. asteriodes causes
pyothorax, sq lesion, co-infection with CDV
in horses, N. asteriodes causes
pyothorax, sq lesion, and abortion
what is the treatment for lesions and mastitis associated with N. asteriodes
lesions - abx, drainage
mastitis - culling
describe the morphology of actinomyces
gram + rods to filamentous bacteria, non-acid fast
what is the pathogenesis of actinomyces in 4 steps
- injury to area normally inhabited
- pyogranulomatous response
- virulence factors help attach and breakdown
- sulfur-containing exudate produced
actinomyces viscosus species infected
dogs
T/F: actinomyces are highly susceptible to abx
TRUE
