Lecture 4 - Clostridum Botulinum And Perfringens Flashcards

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1
Q

What does LUCA mean

A

Last universal common ancestor

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2
Q

Where are c.bot and perf in phylogenetic tree

A

Firmicuttes (gram positive)

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3
Q

What re defining characteristics of

A

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.

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4
Q

How many toxins does a cell normally produce

A

One but can have more than one. Write like e.g. Af (a IS major toxin but f is minor toxin)

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5
Q

Which macedonian ruler in 886-912 banned the eating of blood sausage to prevent deaths (from c. Bot)

A

Emeperor Leo VI

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6
Q

Who originally described botulinum as bacillus botulinus after ham outbreak

A

Van ermengen

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7
Q

Why was it later reclassified to clostridium form bacillus

A

Bacillus are aerobic

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8
Q

How are 4 groups defied for botulinum

A

Proteolysis

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9
Q

What toxin type, proteolysis abilities, saccharolysis (sugar breakdown) and disease host does Group I

A

Tt - A,B,F
P- is proteolytic
S- Negative for saccharolysis
DH - human

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10
Q

What toxin type, proteolysis abilities, saccharolysis (sugar breakdown) and disease host does Group II

A

Tt- B,E,F
P - Negative
S- positive
Human

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11
Q

What toxin type, proteolysis abilities, saccharolysis (sugar breakdown) and disease host does Group III

A

tt- C,D
P - weak
S - negative
H- animal

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12
Q

What toxin type, proteolysis abilities, saccharolysis (sugar breakdown) and disease host does Group IV

A

G

Negative for all others

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13
Q

What about toxin type C and D makes group III particularly problematic

A

C - poultry
D- bcattle

In silage - if small animals get caught up when farmer mowing get anaerobic condition.

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14
Q

Where is c bot distributed

A

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)

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15
Q

Name mesophilic strains of c bot and their requirements

A

TYPES A AND B
Temp - 10-50deg
PH min 4.7 (some tinned foods arent safe)
Aw >0.94 (doesnt like it too dry)

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16
Q

Name a psychrotrophic strain of c bot

A

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

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17
Q

Describe activity of botulinum neurotoxin

A

Exotoxin - produced and secreted outside cell

1- attach to gangliocide receptors
2- bloch Ach release
3- flaccid paralysis

MOST POTENT TOXIN KNOWN

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18
Q

How canbot toxin be destroyed

A

Heating at 80 deg for ten min

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19
Q

How is botulism toxin used in human life

A

Used to relax muscles in forehead and face - botox

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20
Q

What are the three main presentations of botulism

A

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

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21
Q

Why is c bot not more common

A

Very poor competitor

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22
Q

What are products of concern for bot

A

Sous vide - method of preservation (partial cooking then refrigerating)
MAP food - modified atmosphere packaging( plastic base with plastic film mix of gases to preserve but more co2 so bot can grow

Tinned foods - anaerobic in tin - if emerge in tin have time to grow and create toxin

Vegetative cells not very heat resistant but spores are

23
Q

What temp and duration can c bot withstand

A

2hr at 100deg

24
Q

What is incubation, symptoms and duration of foodborne botulism in adults

A

Incubation 12-72hr

Symptoms:

  • nausea, vomiting, sickness, dizziness and headache
  • dryness of skin, mouth and throat
  • constipation, lack of fever, paralysis
  • respiratory failure and death (shut down smooth muscles)

Duration
- 1-10 days

25
Q

Why is botulism toxin considered most toxic known to man

A

1mg of toxin can intoxicate 1 million people

26
Q

When was the last food botulism case reported in uk

A

2005

27
Q

Name two big outbreaks of foodborne botulism

A

Hazelnut yoghurt
Northwest uk 1989 - 25 people got it, 1 died

Tin salmon
Birmingham 1978 -

28
Q

Where is foodborne botulism a big issue and name some causes

A

America
50 people cases in spikes

  • fermented fish/seafood
  • baked potatoes
  • chilli sauce
29
Q

What family in Oregon -1924 had 12 fatalities and why

A

Gerber family hoemcanned string beans

Americans put meat pates etc and put in water and boil them for home canning e.g. Same as British baking cakes

30
Q

Why can you not tell when type E toxin strain is present

A

Non protelytic so make no changes to meat so cannot tell it is there

31
Q

What is biggest future threat of c bot

A

Type e strain

Eat lots of salmon, sushi etc that not really cooked so can be used a vesicle

32
Q

When was last case of infant bot and what age group does infant class as

A

2011

Infants under 1 year

33
Q

How is infant bot infective

A

Ingest spores
Approx 100
Infect via Air, fomites (objects likely to carry an infection e.g. Clothes, utensils)

Lack of gut competitors - produce toxin in gut.

34
Q

What are Group I strains for infant bot

A

A, B, Bf and Ba

Not usually fatal

35
Q

What food cannot be fed to infants under 18 months

A

Honey

36
Q

When was last case on wound botulism (injecting) and what other bacteria does it go hand in hand with

A

2010 3 cases

Anthrax

37
Q

How is c bot diagnosed

A

Clinical observation

Tryptose Sulphite Cycloserine (TSC) media
Anaerobic environment

38
Q

What is the treatment for c bot

A

Antitoxin - stop progression of disease. Early diagnosis crucial for this but tend to be misdiagnosed
Ventilation for respiratory paralysis

For infantile - self limiting, ventilation.

39
Q

What is done to prevent c bot

A

Careful control of canning and preservation

40
Q

State characteristics for c perf

A
Gram + 
Single/pairs RARELY chains 
Anaerobic 
Temp 20-50 op 45 
U - growth rate = 8-10 minutes 
Aw >0.93 
Spores
41
Q

What is interesting characteristic for c perf tht differ from other clostridia

A

Non motile rods

42
Q

Describe the five biotypes of exotoxin produced by perf

A

A- E

Four exotoxins - Alpha, beta, epsilon, iota
Enterotoxin - Cpe
Cause profuse diarhoeal disease

43
Q

Describe spores for c perf

A

Heat resistant
Freezing sensitive
Dessicatin resistant

44
Q

What are reservoirs and distribution of perf

A

Soil, water, food, dust, spices.
Intestines of gut of man and animals

Casseroles, custards, stews, curries, etc - liquids cooked in large volume and allowed yo cool down - cooling process issue
Prepared one day eaten next. Meat dishes food vehicle.

Germinate in cooling phase

45
Q

What are two main presentations of c perf

A

Foodborne

  • abdominal cramps
  • diarrhoea (rarely nausea )

Gas gangrene

  • wound infection
  • swelling
  • tissue necrosis
46
Q

Describe c perf enterotoxin

A

Spore specific protein

Heat sensitive 60 deg for 10 min

Toxin formation in intestine - rarely preformed. We eat organism and it produce toxin in us

Large infective dose - 10^8+

47
Q

What is incubation and duration of c perf food poisoning

A

Incubation - 6-24hr
Duration 12-24h
Fatalities rare

48
Q

How many cases of c perf poising predicted

A

28000

49
Q

How can c perf be prevented food

A

Adequate cooking, cooling, reheating
Hot holding

Keep food above 63 degree and below 5 deg to be safe

50
Q

Is c perf an outbreak or sporadic cases foodborne

A

Sporadic usually

2011 198 people but likely more

51
Q

Describe conditions caused by gas gangrene perf

A

Big in war time. Spores live in soil - little nutrients. Get in wounds.

  • Clostridial myonecrosis (production of gas) - N2, Co2, H2 get stuck in muscle cause vacuole holes.
  • alpha toxin have ZINC METALLOPHOSPHOLIPASE. Hydrolysis of phospholipids so lead to increased vascular permeability - necrotic
52
Q

How is c perf diagnose in lab

A
  • clinical presentation and agar
  • tsc - tryptose sulphite cycloserine. anaerobic environment, selective supplement (black colonies). Egg yolk, lecithinase action show halo (characteristic of c perf)
53
Q

What is treatment and prevention of gas gangrene perf

A

Treatment - debridement. Excision/amputation. Hyperbaric O2 therapy (big chambers, very aerobic - so perf not able to grow).

Prevent gas gangrene - wound management. Take care