Clostridium Clostridium botulinumbotulinum

Prepared by: Shiekha AL-AujanPrepared by: Shiekha AL-Aujan

Clostridium botulinumClostridium botulinum

Characters.Characters. Toxins.Toxins. Pathogenesis.Pathogenesis. Symptoms.Symptoms. Diagnostic laboratory test.Diagnostic laboratory test. Treatment.Treatment. Prevention.Prevention.

CharactersCharacters A gram-positive, anaerobic bacilli.A gram-positive, anaerobic bacilli. Spore forming.Spore forming. Toxin forming. Toxin forming. Heat sensitive.Heat sensitive. Prefers low acid environment.Prefers low acid environment. Cause Botulism disease.Cause Botulism disease.

ToxinsToxins

librated during growth. librated during growth. Seven types of toxins (A-G).Seven types of toxins (A-G). Antigenic (light and heavy chain).Antigenic (light and heavy chain). Environmental survival.Environmental survival.

((Inactivated by heat 100ºC for Inactivated by heat 100ºC for 20min20min ). ).

Most potential biological warfare Most potential biological warfare agents.agents.

Lethal dose= 1-2 Lethal dose= 1-2 gg . .

ToxinsToxins

Botulinum toxin is synthesized as a single Botulinum toxin is synthesized as a single polypeptide chain ( low potency).polypeptide chain ( low potency).

The toxin is nicked by a bacterial protease The toxin is nicked by a bacterial protease (or by gastric proteases) to produce two (or by gastric proteases) to produce two chains :chains :

a light chain (the A fragment)a light chain (the A fragment) a heavy chain (the B fragment)a heavy chain (the B fragment)

connected by a connected by a disulfide bonddisulfide bond.. The A fragment of the nicked toxin, The A fragment of the nicked toxin,

becomes the most potent toxin found in becomes the most potent toxin found in naturenature

Active ToxinActive Toxin

ToxinsToxins

Absorbed in GIT blood Absorbed in GIT blood peripheral neuromuscular synapse.peripheral neuromuscular synapse.

Presynaptic block Acetylcholine Presynaptic block Acetylcholine release (by proteolysis of SNARE release (by proteolysis of SNARE proteins in neuron which is proteins in neuron which is important in Ach release) important in Ach release) muscle paralysismuscle paralysis..

SNARE proteins are synaptobrevin, SNARE proteins are synaptobrevin, SNAP-25 and syntaxin.SNAP-25 and syntaxin.

PathogenesisPathogenesis

transmitted in three ways:transmitted in three ways: Food or water toxin contamination.Food or water toxin contamination. Wound infected with Wound infected with C. Botulinum.C. Botulinum. Ingestion of C. botulinum.Ingestion of C. botulinum.

Most common contaminated food: Most common contaminated food: Vacuum packed, or canned alkaline food.Vacuum packed, or canned alkaline food.

E.g. fish, green beans, any home-canned E.g. fish, green beans, any home-canned food.food.

Foods eaten without cooking.Foods eaten without cooking.

PathogenesisPathogenesis of Infant of Infant BotulismBotulism

Cause :infection by C. botulinum.Cause :infection by C. botulinum. Age: 5 - 20 weeks of age.Age: 5 - 20 weeks of age. Characterized by constipation Characterized by constipation

and weak sucking.and weak sucking. It cause “It cause “sudden infant death sudden infant death

syndrome-SIDSsyndrome-SIDS”.”. found in the stool.found in the stool.

SymptomsSymptoms

appear in 18-24 hrs.appear in 18-24 hrs. include : include : Blurry vision, Double vision.Blurry vision, Double vision. Dry mouth.Dry mouth. Trouble swallowing.Trouble swallowing. Trouble breathing.Trouble breathing. Muscle weakness.Muscle weakness.Fever is not a symptom of botulismFever is not a symptom of botulism

Diagnostic laboratory Diagnostic laboratory testtest

Toxins found in serum, leftover Toxins found in serum, leftover food.food.

Mice injected with toxin die Mice injected with toxin die rapidly.rapidly.

In infants, found in stool.In infants, found in stool. brain scan, spinal fluid brain scan, spinal fluid

examination, nerve examination, nerve conduction test.conduction test.

TreatmentTreatment

Trivalent (A,B,E) antitoxin must Trivalent (A,B,E) antitoxin must administrated intravenously administrated intravenously (recovery takes several weeks)(recovery takes several weeks)

Mechanical respirator is Mechanical respirator is administrated if necessary.administrated if necessary.

preventionprevention

Safe home canning.Safe home canning. boiling the food for 10boiling the food for 10 - 20- 20

minutes before eating it.minutes before eating it. children less than 12 months old children less than 12 months old

shouldshould not be fed honeynot be fed honey (( can can contain sporescontain spores ).).

Thank youThank you