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77 Cards in this Set

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clostriduim - gram neg or positive?
positive (obligate anaerobe, catalase and oxidase neg)
clostridum - spore forming? anaerobe, aerobe
"spore formeing" and obligate anaerobe
clostridium catalase? oxidase?
catalase negative and oxidase negative
noninvaseive, causing botulism, can be an agent of bioterrism
clostridium botulinum
noninvasive (very limited invasion potential) causitive agent of tetanus
clostrium tetani
noninvasive, secretes toxin causing pseudomembranous enterocolitis (a cause of antibiotic-mediated diarrhear)
clostrium difficile
very invasive pathogen, causes has gangrene. type of clostridium
clostridium perfringens
a type of clostridium perfringens which causes invasive malignancy
c. septicum
an extracellular toxin secreted by clostridium which causes flaccid paralysis
botulism toxin
a extracellular toxin secreted by clostridium which causes locked jaw
tetanus toxin
exotoxins secreted by clostridium which cause diarrhea in pseudomembranous colitis due to clostridium difficile
extoxins A and B
a toxin secreted by Clostridium perfringens which is a lecithinase which lyses host cell membrane and in combination with other degradative enzymes as is a cause for "gas gangrene"
alpha toxin
a type of clostridium with subterminal oval spores whose spore location is NOT diagnostic for this species
clostridium botulism
C. botulism comes from what enviroment
soil -
is the botulism toxin heat labile
yes
3 subtypes of C. botulinum spores are found where (3places)
1. Food (canned)
2. wound
3. infant botulism (organism in honey)organism germinates and colonizes gasrointestical tract
concerning the botulism toxin: heat labile? killed by stomach acid?
heat labile (inactivated by boiling for at 100 degrees for 10 minutes) and not destroyed by stomach acid
how does the botulism toxin work?
absorb from intestine
carried via blood
to synapses (neurotoxin)
binds nerve synapse
enters cell
blocks release of Ach
what is the mechanism by which the botulism toxin interfere with Ach release
by proteolytic processing
what is the pts mental state w/ botulism - will they have a fever?
no fever
normal mental state
what muscles may be effected by botulism toxin
respiratory muscles
incubation period for botulism toxin
18-36 hours
why cant you rely on culturing microorganisms for clinical diagnosis of botulism toxin
it is a preformed toxin - not a growing organism
where might you detect botulism toxin
serum, vomitus, feces
where might you detect bacterial toxin formed by clostridium botulinum
food, serum, vomit, feces

also you can get EMG which might be suggestive due to observed decrease in Action potentials
why might a EMG be helpful for the detection of Botulism toxin
you would see the diminished action ptoential of the peripheral nerves results are suggestive not diagnostic
what are two differential diagnoses w/ symptoms similar to bolutism
myasthenia gravis and Guillain Barre syndrome (an ascending paralysis syndrome that can also be distinguished with history of toxin detection
if detected early what might be one treatment of botulism toxin
removal of toxin with lavage
what might you treat botulism toxin poisoning with
horse antitoxin (also can remove from stomach)
how might you inactive toxin in canned food
cook at 100 degrees for 10 minutes
infants 1-8 months of age are at risk of getting infected with infant botulism = - what is this the result of
contaminated honey is common source - bacteria proliferates in gut
symptoms of infant botulism
constipation, weak head control (flaccid), cranial nerve deficit
where might you find toxin re infant botulism toxin
in stool or organism in food
what is the treatment for infant botulism
supportive (due to the allergic reaction to old antitoxin) but you can treat with new human antitoxin Ab (against serotypes A and B)
how might you get wound - associated botulism
spores in soil contaminate wound
the only clostridium with terminal spore (all other species have subterminal spores)
clostridium tetani (spore looks like a tennis racket and is highly diagnostic
how might you contract clostridum tetani
wound contimination with soil
concerning tetanus toxin
# of serotypes?
invasive?
neurotoxin?
1 serotype
non invasive
neurotoxin yes
what are the roles of the two subunits in the tetanus toxin
one binds neuronal ganglioside and the other has neurotoxin activity. they inhibit the release of glycine and GABA
convulsive contractions (locked jaw)and spastic paralysis are a result of what toxin
tetanus
incubation of tetanus
4 days to weeks
how would you diagnose tetanus
clinically - occasionlly you can culture would (39% will be positive)
how do you treat tetanus
human tetanus Ab
penicilin
respiratory support
what is the immunization of tetanus made of
tetanus toxoid
fatality rate of tetanus and due to what
60% due to pulmonary complicaitons and secondary infections
what are the two immunization strategies for tetanus
1. 3 doses of tetanus toxoid first 6 months of life
2. given as DPT. given at 1 year and prior to school entry - booster every ten
is a common cause of antibiotic associated diarrhea due to toxin-mediated inflammation of the colon
C. difficile
when might you be most suseptable to C. difficile
antibiotic-induced suppression of normal flora
Exotoxin A and B does what in c.difficile
entertoxin A binds gut receptor and exotoxin B is cytotoxin which damagies colonic mucose (bloody diarrhea.
what toxin damges colonic mucosa by ADP-ribosylating Rho, a GTP-binding protein leading to pseudomembrane formation
exotoxin B from C. difficile
what are the clinical syndromes associated with C. difficile
diarrhea with pseudomembranes (yellow-white plaque) on colonoscopy or signoidoscopy - sometimes bloody
treatment for C. difficile
stop offending antibiotics
treat with metronizadole or vancomysin
prophylaxis for C. difficile
prudent use of antibiotics
the hallmark of an infection by clostridium perfringens is
tissue necrossis "gas gangrene"
Clostridium and other species which cause gas gangrene are primarily foundin soil but also in what two parts of the human body
GI tract and vagina
this alpha toxin damges host cell membrane including capillary and host erythrocytes and is associated with gas gangrene
lecithinase
the by product of anaerobic growht are what two gases
H2 and CO2
Histotoxic Clostridia is
clostridia assocated with gas gangrene (clostidium perfrngens is the most common)
invading of the fascia around muscle relating to histotoxic clostridia
necrotizing fasciitis
crepitus (upon pressing the skin ) due to the gas in subcutaneous tissue or muscle diagnostic of
C. perfringens
the following clinical symptoms are diagnositic of: discoloration and edema of the skin, extreme pain. serous dark exudates, gram stain of fluid, culture of wound, x-ray
C. perfringens
what is the treatment for C. perfringens
"surgical" wound debridement
penicillin to kill remaining bacteria
Hyperbaric oxygen in selected medical centers
location of spores in bacterium is helpful in what species of clostridium?
clostridium tetani
why would you put clostridium in thioglycolate when transfering them to the lab
its an oxygen reducing agent and clostridium is sensitive to Oxygen (would need ot be in airtight container - no swabbing!)
in which species of clostridium is the invasion of tissue required for toxin production
C. perfingens
person with dirty wound who has had a complete course of toxoid or a booster w/in the past 5 years. treat with?
nothing
person with dirty wound who has had a complete course of toxoid or a booster more than 5 but less than 10 years prior. treat with
toxoid - one dose
dirty wound. person has had complete course or a booster dose more than 10 years ago.
treat with?
toxoid 1 dose + human tetanus IgG
Dirty wound. person has not had complete course of toxoid or immunity status is unknown
toxoid complete course + human tetanus IgG
new, clean, non penetrating wound. person has had complete course of toxoid or a booster w/in past 5 years. treat with
nothing
new, clean, non-penetrating wound. person has had a complete course or booster dose between 5-10 years prior. treat with
toxoid 1 dose
new, clean, non-penetrating wound. person has had a complete course or a booster dose more than 10 years ago
toxoid 1 dose
new, clean, non-penetrating wound. person has not had a complete course of toxoid or immunity status is unknown. treat with?
toxoid complete course
Detection of toxin by a bioassay (for toxin B) or by an ELISA (enzyme linked immunoabsorbent assay) for toxins A & B would be used to diagnose what organism
C. difficile
2nd or 3rd as cause of food poisoning
C. perfingens
besides gas gangrene what other disease is caused often by clostridium perfingens
food poisoning - watery diarrhea
soed clostridium have spores
yes - but only a few