Cl Perf+ Cl Botu

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Cl Perf+ Cl Botu

  1. 1. Clostridium perfringens Clostridium botulinum Dr Kamran Afzal Classified Microbiologist
  2. 2. Clinically important Gram positive bacilli <ul><li>Spore forming </li></ul><ul><li>1. Bacillus </li></ul><ul><li>2. Clostridium </li></ul><ul><li>Non spore forming </li></ul><ul><li>1. Corynebacterium </li></ul><ul><li>2. Listeria </li></ul><ul><li>Bacilli w/ branching filaments </li></ul><ul><li>1. Actinomyces </li></ul><ul><li>2. Nocardia </li></ul>
  3. 3. Spores
  4. 4. Spores <ul><li>Clostridia form endospores under adverse environmental conditions </li></ul><ul><li>Spores are a survival mechanism </li></ul><ul><li>Spores are characterized on the basis of position, size and shape </li></ul><ul><li>Most Clostridium spp., including Cl. perfringens and Cl. botulinum , have ovoid subterminal (OST) spores </li></ul><ul><li>Cl. tetani have round terminal (RT) spores </li></ul>
  5. 5. Classification Based On The Type Of Disease Produced <ul><li>A . Tetanus Cl. tetani - Present in soil </li></ul><ul><li>B. Gas gangrene </li></ul><ul><ul><li>Established Cl. perfringens ‘gut’ organism </li></ul></ul><ul><ul><li>Cl. septicum </li></ul></ul><ul><ul><li>Cl. novyi </li></ul></ul><ul><ul><li>- Less pathogenic Cl. histolyticum </li></ul></ul><ul><ul><li>Cl. fallax </li></ul></ul><ul><ul><li>- Doubtful Cl. bifermentans </li></ul></ul><ul><ul><li>Cl. sporogenes </li></ul></ul>
  6. 6. <ul><li>C. Food poisoning </li></ul><ul><li>1. Gastroenteritis Cl perfringens Type A </li></ul><ul><li>2. Botulism Cl botulinum Soil </li></ul><ul><li>3. Pig-bel Cl perfringens Type C </li></ul><ul><li>D. Acute colitis - Cl difficile Gut </li></ul><ul><li>(pseudomembranous colitis) </li></ul><ul><ul><li>Commonest cause of ‘nosocomial’ diarrhoea </li></ul></ul>
  7. 7. Introductory Characteristics <ul><li>Obligate anaerobes </li></ul><ul><li>Gram positive </li></ul><ul><li>Capable of producing endospores </li></ul><ul><li>Rod-shaped </li></ul><ul><ul><li>Greek word for spindle, kloster </li></ul></ul><ul><li>Club-shaped </li></ul><ul><ul><li>Endospores form club end </li></ul></ul>
  8. 8. Clostridium Associated Human Diseases
  9. 9. Clostridium perfringens
  10. 10. Characteristics <ul><li>Gram positive </li></ul><ul><li>Rod-shaped </li></ul><ul><li>Non-motile </li></ul><ul><li>Anaerobic </li></ul><ul><li>Capsulated </li></ul><ul><li>Double zone of haemolysis </li></ul><ul><li>Five types of strains </li></ul><ul><ul><ul><li>A - E </li></ul></ul></ul><ul><li>Four lethal toxins </li></ul><ul><ul><ul><li>Alpha, Beta, Epsilon and Iota </li></ul></ul></ul>
  11. 11. Epidemiology <ul><li>Lives in soils esp manured and cultivated lands </li></ul><ul><li>Persists in human and animal intestinal tracts and faecal matter </li></ul><ul><li>Can survive higher temp (45 0 C) </li></ul><ul><li>Doubling time can be as short as 8 minutes </li></ul><ul><li>Food poisoning strains produce spores that can resist boiling for several hours </li></ul><ul><li>Gas gangrene strains produce spores that are inactivated by boiling for few minutes </li></ul>
  12. 12. Virulence Factors Major Minor <ul><li>Enzymes </li></ul><ul><ul><li>Hyaluronidase, Proteinase and Collagenase </li></ul></ul>
  13. 13. Lab Diagnosis <ul><li>Large rectangular gram-positive bacilli </li></ul>Inner beta-hemolysis = θ toxin Outer alpha-hemolysis = α toxin <ul><li>Double zone of haemolysis </li></ul><ul><li>Lack of inflammatory cells </li></ul>
  14. 14. <ul><li>Nagler Reaction (egg-yolk agar) </li></ul>NOTE: Lecithinase ( α -toxin; phospholipase) hydrolyzes phospholipids in egg-yolk agar around streak on right. Antibody against α -toxin inhibits activity around left streak Cl perfringens Cl histolyticum Cl septicum Cl novyii
  15. 15. Clostridial food poisoning <ul><li>Cl perfringens </li></ul><ul><li>Heat resistant Enterotoxin </li></ul><ul><li>Carriers for food poisoning strains </li></ul><ul><li>Survival of heat resistant spores in bulk meals </li></ul><ul><li>Sporulation in gut - Short IP and watery diarrhoea for 24-48 hours </li></ul><ul><li>Usually symptoms occur within 6-24 hours of ingestion and can last ~24 hours </li></ul>
  16. 16. <ul><li>Salmonella spp </li></ul><ul><li>Staphylococcus aureus </li></ul><ul><li>Campylobacter spp </li></ul><ul><li>Clostridium perfringens </li></ul>
  17. 17. Necrotizing enteritis (Pig-bel) <ul><li>New Guinea natives have pork feasts </li></ul><ul><li>Clostridia survive in under-cooked meat </li></ul><ul><li>Production of Beta toxin by Cl perfringens Type C </li></ul><ul><li>Beta toxin acts on small intestine </li></ul>
  18. 18. Gas Gangrene
  19. 19. Pathogenesis <ul><ul><ul><li>Dead tissue, blood clots, aerobic organisms </li></ul></ul></ul><ul><ul><ul><ul><ul><li>In an injury </li></ul></ul></ul></ul></ul><ul><li>Development of ANAEROBIC CONDITION </li></ul><ul><li>(Exogenous infection) Germination of spores </li></ul><ul><li>Gas gangrene </li></ul><ul><li>oedema, necrosis, gas production </li></ul><ul><li>toxaemia, myositis </li></ul><ul><li>crepitus </li></ul>
  20. 20. Management <ul><li>Prompt surgical intervention </li></ul><ul><ul><li>Sutures are removed, fascial compartments are incised to release tension, necrotic tissue is debrided </li></ul></ul><ul><li>Hyperbaric oxygen </li></ul><ul><ul><li>Special pressurized chamber </li></ul></ul><ul><li>Antitoxin antiserum </li></ul><ul><ul><li>A polyvalent antitoxin antiserum containing Cl perfringens , Cl novyii and Cl septicum antitoxin </li></ul></ul><ul><ul><li>Now replaced with intensive antimicrobial therapy </li></ul></ul>
  21. 21. <ul><li>Antimicrobial therapy </li></ul>
  22. 22. Clostridium botulinum
  23. 23. Epidemiology <ul><li>Found in soil, sediments of lakes, ponds, coastal waters, decaying vegetation </li></ul><ul><li>Intestinal tracts of birds, mammals and fish </li></ul><ul><li>Usually seen in canned foods </li></ul><ul><ul><li>Hams, sausages, fish, liver paste, honey and home preserved meat products and vegetables </li></ul></ul>
  24. 24. Characteristics <ul><li>Anaerobic Gram-positive bacillus that forms oval sub-terminal spores </li></ul><ul><li>Botulinum Toxin - One of the most poisonous natural substances known </li></ul><ul><li>Seven toxigenic subtypes of the organism </li></ul><ul><ul><li>A, B, C, D, E, F and G </li></ul></ul><ul><ul><li>The principle cause of human disease A,B and E </li></ul></ul>
  25. 25. Spores <ul><li>Spores can withstand boiling in water for several hours </li></ul><ul><li>Destroyed by moist heat at 120 0 C within 5 min </li></ul><ul><li>Insufficient heating in the process of preserving foods – Botulism </li></ul><ul><li>Canning factories should ensure ‘adequate heating’ in all parts of canned contents </li></ul><ul><li>Resistance of some spores to irradiation </li></ul>
  26. 26. Action of Toxin <ul><li>Structure: Synthesized as a polypeptide chain that cleaves into two chains, a light and heavy linked by disulfide bonds </li></ul><ul><li>Blocks release of Ach </li></ul><ul><ul><li>Failure to release neurotransmitter </li></ul></ul><ul><ul><li>Zinc-dependent endopeptidase that </li></ul></ul><ul><ul><li>cleaves synaptobrevins </li></ul></ul><ul><li>Flaccid Paralysis </li></ul><ul><li>Permanent binding and damage </li></ul>
  27. 27. Mechanism of Action of Toxin <ul><li>Toxin is neurotoxic protein </li></ul><ul><li>Not inactivated by stomach / intestinal enzymes </li></ul><ul><li>Destroyed by heating at 100 0 C for 20 mins </li></ul><ul><li>Action : Block release of Acetylecholine at synapses and NMJ of peripheral and cranial nerves - flaccid paralysis </li></ul>
  28. 28. Symptoms <ul><li>Begin 8-36 hours after ingestion </li></ul><ul><li>Length : 2 hours to 14 days after entering circulation </li></ul><ul><li>Preliminary symptoms: weakness, dizziness, dryness of mouth, nausea, vomiting </li></ul><ul><li>After Neurological disturbance: blurred vision, inability to swallow, difficulty in speech, descending weakness of skeletal muscles </li></ul><ul><li>Respiratory paralysis and cardiac failure - death </li></ul>
  29. 29. Clinical Syndromes <ul><li>Flaccid paralysis </li></ul><ul><li>Food-borne: ingestion of foods in which spores have germinated and grown in, considered an intoxication – most common form </li></ul><ul><li>Wound: infects a wound and then produces toxins that spread through the bloodstream – very rare </li></ul><ul><li>Infant: infection establishes itself in the bowels of infants, colonizes and produces the toxin – common source is honey </li></ul><ul><li>Unidentified: source is unknown, usually from intestinal colonization with in vivo production of toxin – usually from surgeries </li></ul>
  30. 30. Lab diagnosis <ul><li>Clinical samples </li></ul><ul><ul><li>Suspected food, faeces or vomitus </li></ul></ul><ul><ul><li>Cl botulinum cultured anaerobically </li></ul></ul><ul><li>Toxin detection </li></ul><ul><ul><li>Toxin-Anti toxin neutralization by inoculation in mice </li></ul></ul>
  31. 31. Treatment <ul><li>Priorities </li></ul><ul><ul><li>To remove unabsorbed toxin from stomach and small intestine </li></ul></ul><ul><ul><li>To neutralize unfixed toxin by giving polyvalent antitoxin (A,B and E) </li></ul></ul><ul><ul><li>To give relevant intensive care and support </li></ul></ul><ul><li>Penicillin or other beta-lactam antibiotics? </li></ul><ul><li>A prophylactic dose of polyvalent antitoxin should be given to all the persons who have eaten ‘suspicious food’ containing botulism toxin </li></ul>
  32. 32. Alternative botulism uses <ul><li>Botox </li></ul><ul><ul><li>A-Type botulism is an </li></ul></ul><ul><ul><li>active ingredient </li></ul></ul><ul><li>Biological Warfare </li></ul><ul><ul><li>Poisonous to humans </li></ul></ul><ul><ul><li>World War II </li></ul></ul><ul><ul><ul><li>gelatin capsules with a lethal dose </li></ul></ul></ul><ul><ul><ul><li>slipped into food or drink </li></ul></ul></ul><ul><ul><ul><li>1 gram crystalline toxin dispersed evenly and inhaled = 1 million deaths </li></ul></ul></ul>
  33. 33. <ul><li>What are the causative agent(s) of gas gangrene? </li></ul><ul><ul><li>Cl. perfringens </li></ul></ul><ul><ul><li>Cl. novyii </li></ul></ul><ul><ul><li>Cl. difficile </li></ul></ul><ul><ul><li>Cl. septicum </li></ul></ul><ul><ul><li>Cl. botulinum </li></ul></ul>
  34. 34. <ul><li>What are the causative agent(s) of gas gangrene? </li></ul><ul><ul><li>Cl. perfringens </li></ul></ul><ul><ul><li>Cl. novyii </li></ul></ul><ul><ul><li>Cl. difficile </li></ul></ul><ul><ul><li>Cl. septicum </li></ul></ul><ul><ul><li>Cl. botulinum </li></ul></ul>
  35. 35. <ul><li>Which one is not a Clostridial toxin? </li></ul><ul><ul><li>Neurotoxin </li></ul></ul><ul><ul><li>Histotoxin </li></ul></ul><ul><ul><li>Aflatoxin </li></ul></ul><ul><ul><li>Enterotoxin </li></ul></ul>
  36. 36. <ul><li>Which one is not a Clostridial toxin? </li></ul><ul><ul><li>Neurotoxin </li></ul></ul><ul><ul><li>Histotoxin </li></ul></ul><ul><ul><li>Aflatoxin </li></ul></ul><ul><ul><li>Enterotoxin </li></ul></ul>

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