[micro] clostridia

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  1. 1. CLOSTRIDIA SPECIES AnO2, Gram +, motile rods Saprophytessoil, gut animals/humans
  2. 2. organisms Botulism Gas gangrene Pseudomembranous colitis Tetanus
  3. 3. Morphology/ culture Spores: wider than diameter of bacillus Position: centre, terminal, subterminal Motile: peritrichous flagellae CULTURE: AnO2, BA COLONIES: SMALL, LARGE, HEMOLYSIS GROWTH: Sugar fermentation, protein digestion, milk stormy fermentation ie clot torn by gas ENZYME : Different
  4. 4. CLOSTRIDIUM BOTULINUM Botulism World-wide Soil, rarely animal feces Spores: heat resistant 100 C many hours R decreased by acid, salt TOXIN: Released on growth, autolysis Ag types: A-G Human pathogen ; A,B,E
  5. 5. TOXIN .CONTD AFOODS E..FISH C .BIRDS D..MAMMALS MOL. WT: 150,000( 100,000 &50,000 fragments by s-s bond Absorbed by gut Bind to pre synaptic memb of motor neurons Cranial nerves, PNS
  6. 6. toxin Neuron proteins( SNARE) inhibit release of Ach at synapse Lack of muscle contraction.paralysis Most lethal toxin: 1-2ug Destroyed by heat at 100 for 20min
  7. 7. PATHOGENESIS 1. FOOD: Intoxication; not infection Canned, alkaline, eaten raw, Vacuum packed, spiced, smoked Spores: germinate, release toxin in AnO2 Ach release blocked and FLACCID PARALYSIS 2. WOUND: A&B
  8. 8. CLINICAL FINDING Food ingestion..18-24 hrs Visual disturbance: in-coordination of eye muscle, double vision Speech difficulty Swallowing difficulty Bulbar paralysis Death, respiratory/cardiac arrest Pt conscious till death Fever; absent, no anti-toxin in blood if recovery
  9. 9. INFANT BOTULISM Common in US Food ingestion Floppy baby: poor feed, weak, paralysis Honey; vehicle Feces: CB, toxin Serum: none
  10. 10. Lab diagnosis TOXIN: in serum & food left overs Mice: I/P injection; death Ag type: neutralization in mice CULTURE: Food remains test for toxin; RIA, Hagglut. Infant: bowel, toxin & CB; not in serum
  11. 11. TREATMENT 1. TRIVALENT ANTI-TOXIN 3 potent anti-toxins; A,B,E Prepared in Horses GIVE I/V 2.Mechanical respiration Mortality brought down INFANTS: Recover on support Anti-toxin given
  12. 12. EPIDEMIOLOGY SOIL; vegetables, fruits, Canning; destroy spores, boil ; 20 minutes before use Home canning: beans, corn, peppers, olives, peas, fresh fish, smoked fish TOXIC: spoiled, ranscid, swelled cans Toxoids: for cattle Bioterrorism, warfare
  13. 13. CLOSTRIDIU TETNAI Soil Animal feces O Ag same Flagellar- several Toxin- same, neurotoxin TOXIN: Tetanospasmin MW: 1,50,000(100,000 & 50,000); s-s bond Motor neurons: Binds pre-synaptic membranes Retrograde axonal movement to neurons SC, B STEM
  14. 14. Toxin moves to inhibitory cells, degrades synaptobrevin, a protein that docks vesicles to pre synap memb. Release of inhibitor is blocked & cells are not inhibited Hyper-reflexia & muscle spasm ensues V. small amounts may be lethal
  15. 15. PATHOGENESIS SITE: devitalized tissue, AnO2 Wound Umbilical stump Burn Injury Surgical suture TOXAEMIA, little infection Spore germination; necrotic tissue, Calcium salts,pyogenic infection; ow oxid-reduction Toxin released, travels & fixes to receptors in CNS
  16. 16. CLINICAL FINDINGS Incubation: 4-5 days.weeks Tonic contraction of voluntry muscles of Injury Jawlock jaw Tetanic spasm on external stimulus Painful Conscious Deathresp failure High mortality
  17. 17. DIAGNOSIS H/O injury d/d strychnine poisoning Culture Anti-toxin given PREVENTION: Active immunization by TOXOID CARE OF WOUND WITH SOIL CONTAMINATION PROPHYLACTIC USE OF ANTI-TOXIN PENCILLIN
  18. 18. 1.Human anti toxin or Tetanus immune globulin 250-500 units I/M.2-4 weeks OR 3000-10,000units to N unbound toxin Neutralizes toxin fixed to nervous tissue 2.Active immunization also done Muscle relaxants, sedation Assisted ventilation Surgical debridement Pencillin; prevent CT growth & super added infection Immunized individual: TOXOID; recall injection
  19. 19. CONTROL Preventable Universal Immunization: TOXOID Formalin treat toxin; concentrate AL salt adsorbed toxoids usedchild: 1 st year 3 injections Booster: after 1 year then before school entry 10 years apart Maintain serum level at 0.01units/ml Children : DPT
  20. 20. clostridia C perfringens C novyi C histolyticum C septicum
  21. 21. CLOSTRIDIA PERFRINGENS INVASIVE INFECTION Myonecrosis Gas gangrene TOXINS: Spreading infection Lethal, necrotizing, hemolytic Alpha toxin: lecithinase; splits CM lecithin Theta toxin: hemlytic, necrotic DNAse, hyalouronidase: digest collagen of s/c, muscle
  22. 22. FOOD POISONING: ENTERO-TOXIN, meat dishes 108cells ingested, diarrhea in 6-18 hrs; hyper-sec in jej, ileum, self limiting Rarely n,v, fever PATHOGENESIS TRAUMA Spore contamination.soil/intestine Sporegerminate in low o-r potential; CELLS MULTIPLY CHO fermented,gas produced,blood supply obst
  23. 23. Spreading factors released Tissue necrosis increases, increased bacterial growth, hemolytic anemia, toxaemia, death Gas gangrene, myonecrosis, mixed infection occurs by toxigenic clostridia Proteolytic clostridia, cocci, gram negative organisms Genital tract: 5% femalesabortion associated C sordelli: endometrial infection, bacteraemia if neoplasia C perferingens type C: children necrotizing enteritis; TOXOID helps
  24. 24. CLINICAL FINDING CONTAMINATION..WOUND, UTERUS.1-3 days crepitations in S/C tissue, musclefoul discharge necrosis..fever, hemolysis, toxaemia, shock..death Cellulitis, fascitis TREATMENT: Amputation Anti-biotic Food poisoning; spores germinate in warmed meat dishes, toin, diarrhea lasts 1-2 days
  25. 25. LAB TESTS SPECIMEN: Wound Pus Tissue Grams: + rods, spore? Met glucose medium BA AnO2: colonies;heolysis, I/D by biochemicals Milk: clot-torn by gas in24 hrs Egg-yolk medium: lecitjinase ppt around colonies Toxin checked; neutralized by anti-toxin
  26. 26. TREATMENT Surgical debridement: prompt, extensive AB; Pencillin Hyperbarric oxygen Anti-toxins as conc. Immune globulin Food poisoning: symptomatic managemnt PREVENTION: EARLY, ADEQUATE CLEANSING SURGICAL DEBRIDEMENT AB. PENCILLIN
  27. 27. CLOSTRIDIUM DIFFICILE DIARRHEA: AB given esp AMP, CLINDAMYCIN C difficile toxin in stool Endoscopy: pseudomembrane localized plaques, microabscesses SYMPTOMS: Diarrhea; watery, bloody cramps fever, leukocytosis T/M: discontinue AB Start V an, Metronidazole
  28. 28. PATHOGENESIS AB; R C difficile proliferate Toxins: A.enterotoxin, cytotoxin bind to brush border receptors Toxin B: cytotoxin Toxins in stool
  29. 29. AB associated diarrhea Mildmoderate Less severe than pseudoMC 25%.....associated with C difficile


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