Lecture 4 - Clostridum Botulinum And Perfringens Flashcards
What does LUCA mean
Last universal common ancestor
Where are c.bot and perf in phylogenetic tree
Firmicuttes (gram positive)
What re defining characteristics of
OBLIGATE anaerobe.- havent got enzymes to deal with oxygen
- gram + sporulating rod (terminal, subterminal, distend the sporangium) normally TERMINAL
- Neurotoxin - A,B,C1,D,E,F & G
(Mosaic variants (two additional toxins between C and D. Cd,Dc.
How many toxins does a cell normally produce
One but can have more than one. Write like e.g. Af (a IS major toxin but f is minor toxin)
Which macedonian ruler in 886-912 banned the eating of blood sausage to prevent deaths (from c. Bot)
Emeperor Leo VI
Who originally described botulinum as bacillus botulinus after ham outbreak
Van ermengen
Why was it later reclassified to clostridium form bacillus
Bacillus are aerobic
How are 4 groups defied for botulinum
Proteolysis
What toxin type, proteolysis abilities, saccharolysis (sugar breakdown) and disease host does Group I
Tt - A,B,F
P- is proteolytic
S- Negative for saccharolysis
DH - human
What toxin type, proteolysis abilities, saccharolysis (sugar breakdown) and disease host does Group II
Tt- B,E,F
P - Negative
S- positive
Human
What toxin type, proteolysis abilities, saccharolysis (sugar breakdown) and disease host does Group III
tt- C,D
P - weak
S - negative
H- animal
What toxin type, proteolysis abilities, saccharolysis (sugar breakdown) and disease host does Group IV
G
Negative for all others
What about toxin type C and D makes group III particularly problematic
C - poultry
D- bcattle
In silage - if small animals get caught up when farmer mowing get anaerobic condition.
Where is c bot distributed
Soil and water
Particularly E in water as attack fish
Generally in soil - <1 per g
Also found in country more than city - find where animals are
Food outbreaks A, B ( food associated) and E (fish)
Name mesophilic strains of c bot and their requirements
TYPES A AND B
Temp - 10-50deg
PH min 4.7 (some tinned foods arent safe)
Aw >0.94 (doesnt like it too dry)
Name a psychrotrophic strain of c bot
Type E
Temp 3.3-45deg
PH min 4.8
Aw- 0.97
Legal limit for fridge is 8 degrees but this organism grow below.
As pyschrotroph drag left side of the bell curve to the left
As troph will tolerate cold but would prefer heat of 40 deg
Describe activity of botulinum neurotoxin
Exotoxin - produced and secreted outside cell
1- attach to gangliocide receptors
2- bloch Ach release
3- flaccid paralysis
MOST POTENT TOXIN KNOWN
How canbot toxin be destroyed
Heating at 80 deg for ten min
How is botulism toxin used in human life
Used to relax muscles in forehead and face - botox
What are the three main presentations of botulism
Infantile - normally baby lying on back or held by tummy in air make effort to life head up whereas for botulism baby wont lift its head
Foodborne, tinned food big player
Wound - syringes and IV drug use e.g. Heroin spores of clostridia - germinate and produce toxin in situ
Why is c bot not more common
Very poor competitor