Chap8- General Principles Flashcards
What is a prion
abnormally folded host protein PrP
What diseases are caused by prions
kuru- spongiform encephalopathie
Creutzfeldt-Jakob disease
Bovine spongiform encephalopathy (mad cow)
variant CJD- from infected bovine
How do prions cause disease
undergo a conformational change that is resistant to proteases
the resitance PrP then convert normal PrPs
how can CJD be transmitted
iatrogenically, surgery, organ transplant, blood transfusion
What is a virus
obligate intracell organism that need host machinery
have genome in a capsid and sometimes encased in lipid membrane
Under a light microscope how can you identify a virsu
inclusion bodies
What are the common viruses with inclusion bodies
cytomegalovirus
herpes
smallpox and rabies
what is a latent infection
nonreplicating form of a virus
What are bacteria
prokaryotes, do not have membrane bound organelles
gram + have single outside layer
gram - have 2 thin lipid bilayers
what are pili on bacteria used for
attach to host cells or ECM
Describe staining of Staph aureus
gram + cocci in clusters- degenerating neutrophils
describe staining of Strep. pneumoniae
gram + elongated cocci in pairs and short chains
describe staining of clostridia species
gram + and -
although tru gram +
What are common gram - rod bacteria
E coli, klebsiella pneumoniae
What is the most common seem gram - diplococci
neisseria gonorrhea
What bacteria causes lyme disease meningoencephalitis
spirochete Borrelia burgdorferi
What bacterium contributes to dental plaque
strep mutans
what are facultative intracellular bacteria
can survive and replicate outside or inside host
what are obligate intracellular bacteria
need the host to survive
are chlamydia and Ricketssia, obligate or facultative
obligate because rely on ATP for energy source
What is the most frequent infection that leads to female sterility
chlamydia trachomatis
scarring fallopian tubes and blindness via conjunctivitis
How does Ricketssia cause damage
injures endothelial cells and causes hemorrhagic vasculitis and sometimes CNS
Rocky Mountain spotted fever and epidemic typhus are examples of what
Ricketssia family
What bacteria are the tiniest free living organisms known
mycoplasma organisms