clostridium botulinum

shape

rod

spore former?

yes

oxygen ?

anaerobic

pH

5-8

water activity

• need high water activity

gram ±

+

what are the 2 types of strain

-proteolytic (mesophilc)

-non-proteolytic (psychotolerant)

characteristic of the 2 types of strain in terms of

	Proteolytic strain	Non-proteolytic strain
Temperature	-mesophilic   -they only grow> 10 degree (not in the fridge, since the proteolytic enzymes need to work)	-psychrotolerant/psychrophric  -T>3  -they can grow in the fridge
pH	More acid tolerant   pH (min) is around 4.7	Less acid tolerant   pH(min) is around 5.0–5.2
Heat resistance of spore	-the spore is heat resistance   -sever heat treatment is needed for spores   Eg. (botulinum book) is essential for low acid food stored at ambient temperature	- the spore is less heat resistance   -since they are less heat resistance heat the product at 90 degree for 10 minutes can inactivate the spores

containmination route of the microbes

1. it is a sporeformer, its spore is widely presents in teh environment(soil, water) therefore it will containminate the raw fruit, vegetables.

2. if the food is not being heated properly the spore will survive and starts to germinate when the evironment is favorable

associated food product

1. vegetable, fruit

2. fish

what is the characteristics of the toxin

1. it is a heat labile neurotoxin produced in food

2. type abef cause human botulism

3. most toxic toxin in the world

what is the mode of action of the dieases

1. the neurontoxin will affect the nerve system

2. the toxin will enter the body and absrobed by the samll intestine

3. then it wil be bind with the nerve end and inhibit the fusion of vesicle with Ache with the membrane

4. as a result, no signal transmit to the muscle cause flaccid paralysis

2. Type A, E : will cut synapse associated protein (SNAP-25) 

• Type B C D F: will cut vesicle associated protein (VAMP) 

symptom of the toxin

Incubation time	12-48 h
Duration	1-8days,
Symptom	Mild: Vomiting, nausea, muscular pain, double vision sever case: stop heart beating -10% of cases lethal, type A produce higher mortality than B or E

what is infant botulism

• infant often have an incomplete growth of microbe flora, which are more vulunerable towards the botulium

• they may consum food contrain botulium and, they will grow in the form of colony and produce toxin in the infant gut

• food related with infant botulism is honey

compare human and infant

Classical botulism	Infant botulism
Preformed toxin ingested	Viable spores ingested
Toxin produced in food	Toxin produced in the infant's gut
Intoxication	Toxico-infection: Intestinal colonization + toxin production

how to prevent (think about the characteristics of the microbes)

1. proper heating, (12 D bot cook )

• it can remove the neurotoxin and the spore of botulium effectively, prevent the growth of microbe in the ambient temperature(especailly for the low acid canned food)

2. addition of salt

• lower the water activity of the product

2. addition of acid

3. extra hurdle for MAP and vaccum

4. low temperature storage since it is a mesophile