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77 Cards in this Set
- Front
- Back
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clostriduim - gram neg or positive?
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positive (obligate anaerobe, catalase and oxidase neg)
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clostridum - spore forming? anaerobe, aerobe
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"spore formeing" and obligate anaerobe
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clostridium catalase? oxidase?
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catalase negative and oxidase negative
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noninvaseive, causing botulism, can be an agent of bioterrism
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clostridium botulinum
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noninvasive (very limited invasion potential) causitive agent of tetanus
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clostrium tetani
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noninvasive, secretes toxin causing pseudomembranous enterocolitis (a cause of antibiotic-mediated diarrhear)
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clostrium difficile
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very invasive pathogen, causes has gangrene. type of clostridium
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clostridium perfringens
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a type of clostridium perfringens which causes invasive malignancy
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c. septicum
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an extracellular toxin secreted by clostridium which causes flaccid paralysis
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botulism toxin
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a extracellular toxin secreted by clostridium which causes locked jaw
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tetanus toxin
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exotoxins secreted by clostridium which cause diarrhea in pseudomembranous colitis due to clostridium difficile
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extoxins A and B
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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"
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alpha toxin
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a type of clostridium with subterminal oval spores whose spore location is NOT diagnostic for this species
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clostridium botulism
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C. botulism comes from what enviroment
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soil -
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is the botulism toxin heat labile
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yes
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3 subtypes of C. botulinum spores are found where (3places)
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1. Food (canned)
2. wound 3. infant botulism (organism in honey)organism germinates and colonizes gasrointestical tract |
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concerning the botulism toxin: heat labile? killed by stomach acid?
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heat labile (inactivated by boiling for at 100 degrees for 10 minutes) and not destroyed by stomach acid
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how does the botulism toxin work?
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absorb from intestine
carried via blood to synapses (neurotoxin) binds nerve synapse enters cell blocks release of Ach |
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what is the mechanism by which the botulism toxin interfere with Ach release
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by proteolytic processing
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what is the pts mental state w/ botulism - will they have a fever?
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no fever
normal mental state |
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what muscles may be effected by botulism toxin
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respiratory muscles
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incubation period for botulism toxin
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18-36 hours
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why cant you rely on culturing microorganisms for clinical diagnosis of botulism toxin
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it is a preformed toxin - not a growing organism
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where might you detect botulism toxin
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serum, vomitus, feces
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where might you detect bacterial toxin formed by clostridium botulinum
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food, serum, vomit, feces
also you can get EMG which might be suggestive due to observed decrease in Action potentials |
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why might a EMG be helpful for the detection of Botulism toxin
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you would see the diminished action ptoential of the peripheral nerves results are suggestive not diagnostic
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what are two differential diagnoses w/ symptoms similar to bolutism
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myasthenia gravis and Guillain Barre syndrome (an ascending paralysis syndrome that can also be distinguished with history of toxin detection
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if detected early what might be one treatment of botulism toxin
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removal of toxin with lavage
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what might you treat botulism toxin poisoning with
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horse antitoxin (also can remove from stomach)
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how might you inactive toxin in canned food
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cook at 100 degrees for 10 minutes
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infants 1-8 months of age are at risk of getting infected with infant botulism = - what is this the result of
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contaminated honey is common source - bacteria proliferates in gut
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symptoms of infant botulism
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constipation, weak head control (flaccid), cranial nerve deficit
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where might you find toxin re infant botulism toxin
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in stool or organism in food
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what is the treatment for infant botulism
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supportive (due to the allergic reaction to old antitoxin) but you can treat with new human antitoxin Ab (against serotypes A and B)
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how might you get wound - associated botulism
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spores in soil contaminate wound
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the only clostridium with terminal spore (all other species have subterminal spores)
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clostridium tetani (spore looks like a tennis racket and is highly diagnostic
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how might you contract clostridum tetani
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wound contimination with soil
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concerning tetanus toxin
# of serotypes? invasive? neurotoxin? |
1 serotype
non invasive neurotoxin yes |
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what are the roles of the two subunits in the tetanus toxin
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one binds neuronal ganglioside and the other has neurotoxin activity. they inhibit the release of glycine and GABA
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convulsive contractions (locked jaw)and spastic paralysis are a result of what toxin
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tetanus
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incubation of tetanus
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4 days to weeks
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how would you diagnose tetanus
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clinically - occasionlly you can culture would (39% will be positive)
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how do you treat tetanus
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human tetanus Ab
penicilin respiratory support |
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what is the immunization of tetanus made of
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tetanus toxoid
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fatality rate of tetanus and due to what
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60% due to pulmonary complicaitons and secondary infections
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what are the two immunization strategies for tetanus
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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 |
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is a common cause of antibiotic associated diarrhea due to toxin-mediated inflammation of the colon
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C. difficile
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when might you be most suseptable to C. difficile
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antibiotic-induced suppression of normal flora
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Exotoxin A and B does what in c.difficile
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entertoxin A binds gut receptor and exotoxin B is cytotoxin which damagies colonic mucose (bloody diarrhea.
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what toxin damges colonic mucosa by ADP-ribosylating Rho, a GTP-binding protein leading to pseudomembrane formation
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exotoxin B from C. difficile
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what are the clinical syndromes associated with C. difficile
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diarrhea with pseudomembranes (yellow-white plaque) on colonoscopy or signoidoscopy - sometimes bloody
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treatment for C. difficile
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stop offending antibiotics
treat with metronizadole or vancomysin |
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prophylaxis for C. difficile
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prudent use of antibiotics
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the hallmark of an infection by clostridium perfringens is
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tissue necrossis "gas gangrene"
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Clostridium and other species which cause gas gangrene are primarily foundin soil but also in what two parts of the human body
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GI tract and vagina
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this alpha toxin damges host cell membrane including capillary and host erythrocytes and is associated with gas gangrene
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lecithinase
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the by product of anaerobic growht are what two gases
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H2 and CO2
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Histotoxic Clostridia is
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clostridia assocated with gas gangrene (clostidium perfrngens is the most common)
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invading of the fascia around muscle relating to histotoxic clostridia
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necrotizing fasciitis
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crepitus (upon pressing the skin ) due to the gas in subcutaneous tissue or muscle diagnostic of
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C. perfringens
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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
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C. perfringens
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what is the treatment for C. perfringens
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"surgical" wound debridement
penicillin to kill remaining bacteria Hyperbaric oxygen in selected medical centers |
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location of spores in bacterium is helpful in what species of clostridium?
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clostridium tetani
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why would you put clostridium in thioglycolate when transfering them to the lab
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its an oxygen reducing agent and clostridium is sensitive to Oxygen (would need ot be in airtight container - no swabbing!)
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in which species of clostridium is the invasion of tissue required for toxin production
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C. perfingens
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person with dirty wound who has had a complete course of toxoid or a booster w/in the past 5 years. treat with?
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nothing
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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
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toxoid - one dose
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dirty wound. person has had complete course or a booster dose more than 10 years ago.
treat with? |
toxoid 1 dose + human tetanus IgG
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Dirty wound. person has not had complete course of toxoid or immunity status is unknown
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toxoid complete course + human tetanus IgG
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new, clean, non penetrating wound. person has had complete course of toxoid or a booster w/in past 5 years. treat with
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nothing
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new, clean, non-penetrating wound. person has had a complete course or booster dose between 5-10 years prior. treat with
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toxoid 1 dose
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new, clean, non-penetrating wound. person has had a complete course or a booster dose more than 10 years ago
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toxoid 1 dose
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new, clean, non-penetrating wound. person has not had a complete course of toxoid or immunity status is unknown. treat with?
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toxoid complete course
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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
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C. difficile
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2nd or 3rd as cause of food poisoning
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C. perfingens
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besides gas gangrene what other disease is caused often by clostridium perfingens
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food poisoning - watery diarrhea
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soed clostridium have spores
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yes - but only a few
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