2/20: Corynebacterium, Listeria, Bacillus, Mycoplasma, Myobacteria Flashcards
Cornebacterium diptheria general info
gram positive, aerobic
Pathogenic cornebacterium diptheria resides on _____
oropharynx
Pathogenic cornebacterium diptheria produces ____
diptheria toxin encoded on lysogenic bacteriophage
Non-pathogenic form of cornebacterium diptheria is called ___
these inhabit ____
diptheroids
These inhabit pharynx, nasopharynx, distal urethra, skin
Diptheria
caused by local (like _____) effects of diptheria toxin
and by systemic (like ____) effects of diptheria toxin
local - severe pharyngitis or tonsilitis
systemic - circulation of toxin ib lood can cause acute myocarditis
The toxin in cornebacterium diptheria is type ___ toxin
it is ___ endotoxin.
Describe the roles of the alpha and beta subunits.
type II toxin
a-b endotoxin (2 protein complex)
beta subunit binds to cell, endocytosis brings into cell
low pH of endocytic vacuole causes unfolding
alpha subunit translocated to the cytoplasm and inhibits protein synthesis
Cornebacterium diptheria is spread via ___
droplets, direct contact, fomites (less often)
T/F: Cornebacterium is found regularly in US
false
less than 10 cases per year because we use VACCINE
Describe the diagnosis of cornebacterium diptheria
clinically, then grown on selective media
Describe the immune response to cornebacterium diptheria
the toxin is antigenic
stimulates production of antibodies during inrection
What is the inactivated form of cornebacterium diptheria toxin used as a vaccine?
What is the immune response to this?
formalin = inactivated toxin used as vaccine
this is still antigenic - stimulates antibody production
Describe the prevention of diptheria
Immunizations provide protection against infections
Done in 3-4 shots in the first years of life, boosters every 10 years
Describe the treatment of diptheria
early administration of antitoxin, pencicllin, cephalosporin, erythromycin, tetracycline
Describe listeria monocytogenes general info
gram positive, bacilli (can resemble cornyebacterium and streptococci), aerobic (distinguishes it from strep)
How do we distinguish listeria monocytogenes from cornebacterium diptheria in terms of BACTERIOLOGY?
listeria monocytogenes = tumbling motility on fluid media at templs below 30* C, grows well on rich media at temps as low as 0* C
Listeria monocytogenes is the only listeria species that is _____ in humans
pathogenic
Listeriosis usually only presents itself when there is ____
widespread infection
associated w/ listeria monocytogenes
Foodborne outbreaks of listeriosis, symptoms = _____
nausea, stomach pain, diarrhea
widespread infection of listeriosis symptoms - ______
fever, malaise, occasional bacteremia
can cause encephalitis ad meningitis
What are the 3 main virulence factors of listeria monocytogenes?
- internalin
- lysteriolysin O
- actin polymerization
Why is internalin is a major virulence factor for listeria monocytogenes?
internalin attach to the host cells so that the bacteria can be taken up by endocytosis
Why is lysteriolysin O a major virulence factor for listeria monocytogenes?
lysteriolysin O lyses the endocytic vacuole and the bacteria is spread to the cytoplasm to replicate
Why is actin polymerization a major virulence factor for listeria monocytogenes?
actin polymerization allows it to properl itself from cytoplasm to the neighboring cell
Where is listeria monocytogenes found?
ubiquitous to soil, water, GI tracts of animals
foodborn pathogens spread from deli meat, dairy, uncooked food stored at low temps
Why is listeria monocytoenes hard to eliminate?
because of formation of biolfilm
Who is most susceptible to infection of listeria monocytogenes?
infants and elderly
How do we diagnose infection of listeria monocytogenes?
blood/CSSF culture which would show beta-hemolytic gram positive rods
The immune response for listeria monocytogenesis infection requires _____
innnate response (neutrophils killing bacteria)
and adaptive response (t-cell immunity for clearing infection and long-term protection)
Wha tis the treatment for monocytogenesis?
how is this different fro immunocopromised patients?
ampicillin, trimethoprim/sulfamethoxazole
immunocompromised patients = ampicillin + gentamycin
How can listeria monocytogenes be prevented?
avoid unpasteurized dairy products
thoroughly cook animal products
Describe bacillus anthrasis general info
gram positive, spores, forming long chain rods, aerobic, non-motile, grows well on rich media
Bacillus anthrasis contain endospores making it ______
very hardy, can survive well for decades in an environment
Bacillus anthrasis dwell in the ___
soil
Bacillus anthrasis produces ____ (potent endotoxin)
anthrax A
Human anthrax is usually an ______
ulcerative sore on an exposed part of the body
usually resolves without complications
How is human anthrax caused?
endospore germinates when it lands on human skin due to rich environment
When human anthrax, edema is present at site of infection caused by ____
adenylate cyclase activity of the toxin
What happens of the endospore of bacillus anthrasis is inhaled?
may cause pneumonia which could lead to respiratory failure/death
What is the major virulence factor associated with bacillus anthrasis?
glutamic acid capsule (anti phagocytic)
Anthrax primarily infects _____. How do they acquire this? How does this spread?
anthrax = toxin in bacillus anthrasis bacteria
primarily infects herbivores (cattle, horses) who acquire it from their pastures
humans can become infected when in contact with the animals (or in biological warfare)
How do we diagnose bacillus anthrasis infection?
culture of skin lesion (ulcerative sore), sputum or blood, CSF
Describe the immune response to bacillus anthrasis infection
specific mechanism unknown
experimental evidence says antibodies directed against toxin
Describe preventative measures against bacillus anthrasis infection
euthanize animal
vaccinate!
Describe mycoplasma and ureaplasma general info
smallest free living micro organisms
lacks cell wall
highly plemorphic (appear as coccoid bodies, filament,s bottle shaped)
cell boundary is a single trilaminar membrane that contains sterols
Mycoplasma and ureaplasma : anaerobes or aerobes?
most are facultative anaeroes
exception: mycioplasma pneumoniae = aerobic
How do mycoplasma and ureaplasma appear on special mycoplasma agar?
“fried egg”
What toxin is associated with mycoplasma and ureaplasma?
CARDS toxin
What does CARDS toxin do?
associated w/ mycoplasma and ureoplasma
interferes with ciliary action, causing nuclear vacuolization and fragmentation of trachael epithelial cells that lead to inflammation and de-squamation of mucosa
What major disease do mycoplasma and ureaplasma cause?
walking pneumonia (infection of trachae, bronchi, bronchioles, alveoli)
pharyngitis and otitis are common
Mycoplasma and ureoplasma account for ___% of all pneumonia cases
10
Mycoplasma and ureaplasma are acquired by ____
ID level _____
what time of year ____
outbreaks occur within ____)
acquired via droplet spread
low ID (100)
Occurs throughout the year commonly among teenagers
outbreaks occur within families or closed communities
Describe the immunology of mycoplasma nad ureaplasma infection
b and t cell mediated responses
antibody titers peak at 2-4 weeks after infection
disappear gradually over 6-12 months
Describe diagnosis of mycoplasma and ureaplasma infection
via COMPLEMENT FIXATION
cannot use traditional staining and culturing due to slow growth/lack of cell wall
Describe treatment of mycoplasma and ureaplasma infections
macrolides, doxycycline, fluoroquinolones
Descrine prevention of mycioplasma and ureaplasma infections
no vaccine
T/F: mycoplasma and ureaplasma can cause STIs
true
mycoplasma genitalium and 2 species of ureaplasma may join n. gonorrhoeae and chlamydia trachomatis as STI causes
Describe mycobacteria general info
slim, poorly staining, ACID FAST, obligate aerobes, non-motile
Mycobacteria have
pathogenic species in ____
nonpathogenic species in ____
pathogenic - in animals
non pathogenic - in environment
Mycobacteria are unique due to their ____ cell wall
lipid rich cell wall
The main infection caused by mycobacteria is ____
What is this?
mycobacterium tuberculuosis
systemic infection usually manifested only by evidence of an immune response in most people
Mycobacterium tuberculosis can progress or reactivate after ____
When does this disease become particularly devastating?
after asymptomatic period (of years)
becomes particularly devastating when spreads outside of lungs and reaches CNS
What are the symptosm of mycobacterium tuberculosis
chronic pneumonia with fever, cough, blood sputum, weight loss
1 cough generates ___ infected droplets of mycobacteria
3000
and it only takes less than 10 droplets to infect
An infected droplet of mycobacterium is inhaled, it replicates in ____, spreads through ____ and into ___
replicates in alveoli, spreads through lymph, and into blood stream
multiples inside inactivated macrophages
Mycobacterium tuberculosis causes ___ response.
If this is successful, ____
If this is unsuccessful, _____
TH 1 response (body’s attempt to activate the macrophages, because mycobacterium are replicating in INACTIVATE macrophages)
if successful - stops disease
if unsuccessful - delayed-type hypersensitivity (DTH) continues
Describe the immune response to mycobacterium tuberculosis
TH 1 innate response
cytotoxic CD8+ lymphocytes may participate
How do we diagnose mycobacterium tuberculosis?
acid fast stain, PCR, tuberculin test, or quantiferon gold test
What is the treatment for mycobacterium tuberculosis?
first drug of isoniazid, ethambutol, rifampin, pyrazinamide
second drug of para-aminosalicylic acid, ethionamide, cycloserine, fluoriquinones
What is the prevention for mycobacterium tuberculosis?
BCG vaccine
