clostridium botulinum prepared by: shiekha al-aujan

of 17/17
Clostridium Clostridium botulinum botulinum Prepared by: Shiekha AL-Aujan Prepared by: Shiekha AL-Aujan

Post on 29-Dec-2015

237 views

Category:

Documents

3 download

Embed Size (px)

TRANSCRIPT

  • Clostridium botulinum Prepared by: Shiekha AL-Aujan

  • Clostridium botulinumCharacters.Toxins.Pathogenesis.Symptoms.Diagnostic laboratory test.Treatment.Prevention.

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

  • Toxins librated during growth. Seven types of toxins (A-G). Antigenic (light and heavy chain).Environmental survival. (Inactivated by heat 100C for 20min ).Most potential biological warfare agents. Lethal dose= 1-2 g .

  • ToxinsBotulinum toxin is synthesized as a single polypeptide chain ( low potency).The toxin is nicked by a bacterial protease (or by gastric proteases) to produce two chains :a light chain (the A fragment)a heavy chain (the B fragment) connected by a disulfide bond.The A fragment of the nicked toxin, becomes the most potent toxin found in nature

  • Active Toxin

  • ToxinsAbsorbed in GIT blood peripheral neuromuscular synapse.Presynaptic block Acetylcholine release (by proteolysis of SNARE proteins in neuron which is important in Ach release) muscle paralysis.SNARE proteins are synaptobrevin, SNAP-25 and syntaxin.

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

    Most common contaminated food: Vacuum packed, or canned alkaline food. E.g. fish, green beans, any home-canned food.Foods eaten without cooking.

  • Pathogenesis of Infant Botulism Cause :infection by C. botulinum.Age: 5 - 20 weeks of age.Characterized by constipation and weak sucking.It cause sudden infant death syndrome-SIDS.found in the stool.

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

  • Diagnostic laboratory test

    Toxins found in serum, leftover food. Mice injected with toxin die rapidly. In infants, found in stool. brain scan, spinal fluid examination, nerve conduction test.

  • Treatment

    Trivalent (A,B,E) antitoxin must administrated intravenously (recovery takes several weeks)Mechanical respirator is administrated if necessary.

  • preventionSafe home canning. boiling the food for 10 - 20 minutes before eating it.children less than 12 months old should not be fed honey ( can contain spores ).

  • Thank you