6 - Clostridium Botulinum Flashcards
The four faces of Clostridium botulinum:
1) Intoxication - ingestion (or injection) of the toxin
2) Infant Botulism - Ingestion and intestinal proliferation of the organism, internal production of the toxin (Infection)
3) Wound Botulism - Deep wound results in anaerobic environment
4) Bioterrorism - Deliberate delivery of toxin to large populations
T OR F: By definition all C.botulinum strains are toxic
T
Non-toxic variant strains, though genetically related, are assigned to different species such as: C.__________ and C.______________
sporogenes
subterminale
Botulinum neurotoxin (BoNT) is an _____ toxin that consists of two subunits
A-B
The toxin is __________ after production
inactive
There are 2 types of Cb _____________ and ________________
proteolytic
nonproteolytic
In nonproteolytic Cb the host’s ______________ cleave the toxin (activating it)
stomach acids
In proteolytic Cb the bacteria produce a ___________ that activates the neurotoxin
protease
Following ingestion the toxin molecules are _______________________________
absorbed by the gut and are spread via the blood to peripheral nerves
What happens when the Botulism toxin is ingested?
- Following ingestion/production the toxin molecules are absorbed by the gut and are spread via the blood to peripheral nerves
- Normally the axon terminal of the neuron connects with muscle tissues through SNARE proteins and releases acetylcholine into the muscle cells which causes the muscle contraction
- BoNT acts as a protease cleaving the SNARE proteins
- This deprives the muscle of the acetylcholine signal and result sin flaccid paralysis
- Major issues when it comes to lung or heart muscles
There are several structurally similar, but immunologically distinct BoNTs distinguished using the letters _________
A to G
Cb strains were grouped into ___ groups based on physiological differences, but these groupings don’t correlate to which groups produce which type of toxin
4
Human illness is generally caused by Group _ and Group _ Cb
1 & 2
Group 1: C. botulinum _ and proteolytic strains of _ and
_ (Human)
A
B
F
Group 2: C. botulinum _ and non-proteolytic strains of _ and _ (Human)
E
B
F
T OR F: Group 3: C. botulinum C and D (Animal)
T
Group 4: C. botulinum _
G
How do you test for Cb toxin?
1) Prepare food, feces, serum or gastric contents
2) Dispense filtrate into 3 tubes
3) no treatment tube, tube boiled for 10 min, trypsin asses to tube
4) Inject 2 mice with each tube
5) Treat No treatment tube with A toxin antiserum, B toxin Antiserum & F toxin Antiserum
6) Inject a mouse with each tube, the one that survives = you have to give that anti-toxin to the patient
Main properties of Group 1 Cb: toxin type: proteolysis: lipase production: main physiological property: optimum growth temp: minimum growth temp: causes botulism in:
A, proteolytic B,F \+ \+ Highly thermoresistant spores 37C 10-12C Humans
Main properties of Group 2 Cb: toxin type: proteolysis: lipase production: main physiological property: optimum growth temp: minimum growth temp: causes botulism in:
E, non-proteolytic B,F - \+ Moderately thermoresistant spores 25C 2.5-3C Humans
Cb genomes has a very low ______ content (27-28%)
G+C
Most strains also contain _______ that vary in size
plasmids
The BoNT toxin can be carried either on the ________ or on a _______
chromosome
plasmid
The similarity of the different BoNTs, the ability of different species to produce BoNT, and the fact that some strains contain combinations of bont genes suggests that all bont genes derive from a similar __________ – and move around
ancestor
Easy __________________ can be achieved by mobilization of the plasmids that carry BoNT toxins
horizontal transfer of genes
The possibility of C. ________ picking up a BoNT toxin is a serious concern
difficile
T or F: Cb is found almost ubiquitously in soils, you probably consume several spores daily
T
How does Cb survives?
By secreting numerous hydrolytic enzymes and then transporting the degradation products into the cell (such as AA, small peptides, carbohydrates)
Over ______ genes for transport systems have been identified
300
Cb lacks several genes for _____________
amino acid synthesis
Cb is a strict ___________
anaerobe (has a fermentative metabolism)
Cb is a ______________ microorganism that secretes various hydrolytic enzymes to uptake nutrients
saprophytic
Classic intoxication case:
harvesting a variety of low acids vegetables and doing home-canned soup, not checking the pH and not boiling for 10 mins before consumption
what is muktuk:
raw or fermented beluga whale blubber
Cb is sensitive to low pH and cannot germinate
4.6
Cb is sensitive to high salt and cannot germinate in more than ___% salt
5.5
In natural environments (or the human gut) Cb is ________________ by other organisms and does not grow and produce toxin
outcompeted
The toxin is heat ________, so if canned goods are boiled for 10 minutes before consumption, this is not a problem
liable
What are some foods associated with C.botulinum:
- fermented fish (E toxin)
- low acid fruits and vegetables (A & B toxin)
In adults how do we treat botulism?
with an antitoxin antibodies
In babies how do we treat botulism?
antibiotics + antitoxins antibodies
Does the baby infected with botulism has fever?
no
In wound botulism, the __________ makes the toxin
concentration
Clostridium botulinum spores are found to be _________ in the environment
widespread
They are routinely consumed by adults who are resistant to colonization due to _____________________
healthy gut microbiomes
T OR F: Adults must ingest BoNT to become sick, BoNT is produced in foods which become contaminated and have the right conditions for bacterial growth (anaerobic, pH above 4)
T
T OR F: Infants can become colonized with Clostridium botulinum, BoNT is produced in the child’s gut and child displays Infant Botulism (Infection)
T
