clostridium botulinum prepared by: shiekha al-aujan
Post on 29-Dec-2015
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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
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.
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 ).