1. 1 The Gram-Positive Bacilli of Medical Importance Chapter 19

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4. 4 Bacillus gram-positive, endospore-forming, motile rods gram-positive, endospore-forming, motile rods mostly saprobic mostly saprobic aerobic & catalase positive aerobic & catalase positive source of antibiotics source of antibiotics primary habitat is soil primary habitat is soil three species of medical importance three species of medical importance B. anthracis B. anthracis B. cereus B. cereus B. subtillis B. subtillis

5. Bacillus spore 5

6. 6 Bacillus anthracis 1877 – Robert Koch 1877 – Robert Koch Anthrac is Greek for coal Anthrac is Greek for coal Large (one of the largest), block shaped rods Large (one of the largest), block shaped rods central spores that develop under all conditions, except in the living body central spores that develop under all conditions, except in the living body virulence factors – capsule & exotoxins virulence factors – capsule & exotoxins 3 types of human anthrax 3 types of human anthrax Cutaneous – spores enter through skin, black sore- eschar; least dangerous Cutaneous – spores enter through skin, black sore- eschar; least dangerous Pulmonary –inhalation of spores, most dangerous Pulmonary –inhalation of spores, most dangerous Bacteremia, speen, dies quickly Bacteremia, speen, dies quickly Gastrointestinal – ingested spores in contaminated meat Gastrointestinal – ingested spores in contaminated meat

7. Zoonotic disease (cattle/sheep) Zoonotic disease (cattle/sheep) Affected animals must be burned Affected animals must be burned Problems with leather jackets, violin bows and shaving bristles Problems with leather jackets, violin bows and shaving bristles Very low incidence : 27 cases in 1969-79 Very low incidence : 27 cases in 1969-79 Russia 1979—66 died Russia 1979—66 died treated with penicillin or tetracycline treated with penicillin or tetracycline vaccine – toxoid 6X over 1.5 years; annual boosters (side effects?) vaccine – toxoid 6X over 1.5 years; annual boosters (side effects?) Very easy to grow in lab Very easy to grow in lab Bio-terrorist threat Bio-terrorist threat After 9/11 6 people died from Anthrax After 9/11 6 people died from Anthrax 7

8. Anthrax 8

9. Anthrax Spore 9

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11. Cutaneous Anthrax 11

12. Cutaneous Anthrax - Eschar 12

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15. 15 Bacillus cereus common airborne & dustborne common airborne & dustborne grows in foods, spores survive cooking & reheating grows in foods, spores survive cooking & reheating ingestion of toxin-containing food causes nausea, vomiting, abdominal cramps & diarrhea ingestion of toxin-containing food causes nausea, vomiting, abdominal cramps & diarrhea Begin ½ half to six hours after eating Begin ½ half to six hours after eating 24 hour duration usually self-limiting 24 hour duration usually self-limiting no treatment no treatment spores abundant in the environment spores abundant in the environment

16. Bacillus cereus 16 Very common in certain foods that are being reheated a number of times Very common in certain foods that are being reheated a number of times Potatoes, meat, rice Potatoes, meat, rice Nausea, vomiting, cramps, diarrhea Nausea, vomiting, cramps, diarrhea 24 hour food poisoning 24 hour food poisoning Self-limiting Self-limiting

17. B. cereus 17

18. Bacillus cereus 18

19. Culprit? 19

20. B. subtillis Used in lab research Used in lab research Usually opportunistic Usually opportunistic Can be used as a probiotic Can be used as a probiotic Eye infections Eye infections Lung and blood infections Lung and blood infections Can get into spoiled bread dough and cause “ropiness” Can get into spoiled bread dough and cause “ropiness” 20

21. B. subtillis 21

22. 22 Clostridium gram-positive, spore-forming rods gram-positive, spore-forming rods anaerobic & catalase negative anaerobic & catalase negative 120 species 120 species oval or spherical spores produced only under anaerobic conditions oval or spherical spores produced only under anaerobic conditions synthesize organic acids & alcohols & exotoxins synthesize organic acids & alcohols & exotoxins cause wound & tissue infections & food intoxications cause wound & tissue infections & food intoxications

23. 23 Clostridium perfringens Found in intestinal tracts Found in intestinal tracts Causes gas gangrene in damaged or dead tissues Causes gas gangrene in damaged or dead tissues Produces a gas that putrifies muscle protein (fermentation of carbohydrates) Produces a gas that putrifies muscle protein (fermentation of carbohydrates) 2 nd most common cause of food poisoning, worldwide (meat, poultry, beans) 2 nd most common cause of food poisoning, worldwide (meat, poultry, beans) Symptoms develop 6 to 72 hours Symptoms develop 6 to 72 hours Pain, swelling, dark yellow-green then black, foul odor Pain, swelling, dark yellow-green then black, foul odor virulence factors virulence factors toxins – alpha toxin – causes RBC rupture, edema & tissue destruction toxins – alpha toxin – causes RBC rupture, edema & tissue destruction collagenase collagenase hyaluronidase hyaluronidase DNase DNase

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25. Warning! Warning! Graphic Pictures! Graphic Pictures! 25

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31. Frostbite (dry gangrene) 31

32. 32 Clostridium perfringens Consumption of large amount of vegetative cells produces enterotoxin—clostridial food poisoning Consumption of large amount of vegetative cells produces enterotoxin—clostridial food poisoning Meat, poultry, and beans Meat, poultry, and beans

33. 33 Clostridium tetani common resident of soil & GI tracts of animals common resident of soil & GI tracts of animals causes tetanus or lockjaw, a neuromuscular disease causes tetanus or lockjaw, a neuromuscular disease spores usually enter through accidental puncture wounds, burns, umbilical stumps, frostbite, & crushed body parts spores usually enter through accidental puncture wounds, burns, umbilical stumps, frostbite, & crushed body parts tetanospasmin – neurotoxin causes paralysis tetanospasmin – neurotoxin causes paralysis vaccine booster needed every 10 years vaccine booster needed every 10 years

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38. 38 Clostridium botulinum Causes 3 diseases 1. food poisoning -spores are in soil, may contaminate vegetables; improper canning does not kill spores & they germinate in the can producing botulinum toxin toxin causes paralysis by preventing release of acetylcholine toxin causes paralysis by preventing release of acetylcholine 2. infant botulism – caused by ingested spores that germinate & release toxin 3. wound botulism – spores enter wound & cause food poisoning symptoms

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40. 40 Clostridium difficile normal resident of colon, in low numbers normal resident of colon, in low numbers causes antibiotic-associated colitis causes antibiotic-associated colitis treatment with broad-spectrum antibiotics kills the other bacteria, allowing C. difficile to overgrow treatment with broad-spectrum antibiotics kills the other bacteria, allowing C. difficile to overgrow produces entertoxins that damage intestine produces entertoxins that damage intestine major cause of diarrhea in hospitals major cause of diarrhea in hospitals

41. 41 Listeria monocytogenes non-spore-forming gram-positive non-spore-forming gram-positive ranging from coccobacilli to long filaments ranging from coccobacilli to long filaments 1-4 flagella 1-4 flagella no capsules no capsules resistant to cold, heat, salt, pH extremes & bile resistant to cold, heat, salt, pH extremes & bile primary reservoir is soil & water primary reservoir is soil & water can contaminate foods & grow during refrigeration can contaminate foods & grow during refrigeration Cheese, milk products, fruit Cheese, milk products, fruit Listerosis in immunocompromised patients, fetuses & neonates affects brain & meninges Listerosis in immunocompromised patients, fetuses & neonates affects brain & meninges 20% death rate 20% death rate ampicillin & trimethoprimsulfamethoxazole ampicillin & trimethoprimsulfamethoxazole Prevention – pasteurization & cooking Prevention – pasteurization & cooking

42. Listeriosis Cases as of Feb. 2015 (carmalized apples) 42

43. 43 Erysipelothrix rhusiopathiae gram-positive rod widely distributed in animals & the environment gram-positive rod widely distributed in animals & the environment primary reservoir – tonsils of healthy pigs primary reservoir – tonsils of healthy pigs enters through skin abrasion, multiples to produce erysipeloid, dark red lesions enters through skin abrasion, multiples to produce erysipeloid, dark red lesions penicillin or erythromycin penicillin or erythromycin vaccine for pigs vaccine for pigs

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46. 46 Corynbacterium diptheriae gram-positive irregular bacilli (palisade) gram-positive irregular bacilli (palisade) Aerobic, produces catalase Aerobic, produces catalase possess mycolic acids & a unique type of peptidoglycan possess mycolic acids & a unique type of peptidoglycan Have metachromatic granules stain as spots Have metachromatic granules stain as spots Club shaped Club shaped 2 stages of disease 2 stages of disease local infection –upper respiratory tract local infection –upper respiratory tract Slow healing ulceration called cutaneous diphtheria Slow healing ulceration called cutaneous diphtheria diptherotoxin production & toxemia diptherotoxin production & toxemia

47. Pseudo-membrane formation can cause asphyxiation Pseudo-membrane formation can cause asphyxiation whitish- green gray film will develop in the throat whitish- green gray film will develop in the throat Symptoms: sore throat, fever, fatigue, malaise, swelling in neck Symptoms: sore throat, fever, fatigue, malaise, swelling in neck Death results from heart and kidney failure due to spread of toxin Death results from heart and kidney failure due to spread of toxin Treatment: anti-toxin to neutralize the exotoxin, penicillin Treatment: anti-toxin to neutralize the exotoxin, penicillin Vaccine: 3 shots- DPT Vaccine: 3 shots- DPT Humans only reservoir Humans only reservoir 47

48. C. diphtheriae 48

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51. 51 Propionibacterium acnes gram-positive rods gram-positive rods aerotolerant or anaerobic aerotolerant or anaerobic nontoxigenic nontoxigenic common resident of sebaceous glands common resident of sebaceous glands causes acne causes acne

52. 52 Propionibacterium acnes

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54. 54 Mycobacteria gram-positive irregular bacilli gram-positive irregular bacilli acid-fast staining (stain must be heated) acid-fast staining (stain must be heated) strict aerobes strict aerobes produce catalase produce catalase possess mycolic acids & a unique type of peptidoglycan possess mycolic acids & a unique type of peptidoglycan do not form capsules, flagella or spores do not form capsules, flagella or spores grow slowly grow slowly Mycobacterium tuberculosis Mycobacterium tuberculosis Mycobacterium leprae Mycobacterium leprae

55. 55 Mycobacterium tuberculosis Isolated in 1882 by Robert Koch Isolated in 1882 by Robert Koch produces no exotoxins or enzymes that contribute to infectiousness produces no exotoxins or enzymes that contribute to infectiousness contain complex waxes & cord factor that prevent destruction by lysosomes of macrophages contain complex waxes & cord factor that prevent destruction by lysosomes of macrophages transmitted by airborne respiratory droplets transmitted by airborne respiratory droplets Turn of 20 th century leading cause of death in world (1/7) Turn of 20 th century leading cause of death in world (1/7) only 5% infected people develop clinical disease only 5% infected people develop clinical disease

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57. 57 Primary TB Minimum infectious dose 10 cells Minimum infectious dose 10 cells 20% no infection (-)/ 80% infection (+) 20% no infection (-)/ 80% infection (+) phagocytosed by alveolar macrophages & multiply intracellularly phagocytosed by alveolar macrophages & multiply intracellularly after 3-4 weeks immune system attacks, forming tubercles, granulomas consisting of a central core containing bacilli surrounded by WBCs after 3-4 weeks immune system attacks, forming tubercles, granulomas consisting of a central core containing bacilli surrounded by WBCs The disease usually stops here The disease usually stops here

58. Tubercle 58

59. Tubercle Granuloma 59

60. 60 Secondary TB Bacilli can be latent for years Bacilli can be latent for years Reactivation (re-exposure) of bacilli Reactivation (re-exposure) of bacilli tubercles expand & drain into the bronchial tubes & upper respiratory tract tubercles expand & drain into the bronchial tubes & upper respiratory tract gradually patient experiences more severe symptoms gradually patient experiences more severe symptoms violent coughing, greenish or bloody sputum, fever, anorexia, weight loss, fatigue, chest pain violent coughing, greenish or bloody sputum, fever, anorexia, weight loss, fatigue, chest pain untreated 60% mortality rate untreated 60% mortality rate

61. 61 Extrapulmonary TB during secondary TB, bacilli disseminate to regional lymph nodes, kidneys, long bones, genital tract, brain, meninges during secondary TB, bacilli disseminate to regional lymph nodes, kidneys, long bones, genital tract, brain, meninges Obviously, not a good outcome Obviously, not a good outcome

62. 62 Diagnosis 1. in vivo or tuberculin testing 2. X rays 3. direct identification of acid-fast bacilli in specimen 4. cultural isolation and biochemical testing

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70. 70 Treatment of TB 20-25 million worldwide active TB 20-25 million worldwide active TB 3 million die/year 3 million die/year 6-24 months of at least 2 drugs from a list of 11 6-24 months of at least 2 drugs from a list of 11 one pill regimen called Rifater (isoniazid, rifampin, pyrazinamide) one pill regimen called Rifater (isoniazid, rifampin, pyrazinamide) vaccine based on attenuated bacilli Calmet-Guerin strain of M. bovis used in other countries vaccine based on attenuated bacilli Calmet-Guerin strain of M. bovis used in other countries

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72. 72 Mycobacterium leprae Hansen’s bacillus Hansen’s bacillus strict parasite – has not been grown on artificial media or tissue culture strict parasite – has not been grown on artificial media or tissue culture slowest growing of all species slowest growing of all species multiplies within host cells in large packets called globi multiplies within host cells in large packets called globi causes leprosy, a chronic disease that begins in the skin & mucous membranes & progresses into nerves causes leprosy, a chronic disease that begins in the skin & mucous membranes & progresses into nerves

73. 73 Leprosy – Hansen’s Disease endemic regions throughout the world endemic regions throughout the world spread through direct inoculation from leprotics spread through direct inoculation from leprotics 2 forms 2 forms tuberculoid – superficial infection without skin disfigurement which damages nerves and causes loss of pain perception tuberculoid – superficial infection without skin disfigurement which damages nerves and causes loss of pain perception lepromatous – a deeply nodular infection that causes severe disfigurement of the face & extremities lepromatous – a deeply nodular infection that causes severe disfigurement of the face & extremities treatment by long-term combined therapy treatment by long-term combined therapy

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82. 82 Actinomycetes Genera Actinomyces & Nocardia are nonmotile filamentous bacteria related to mycobacteria Genera Actinomyces & Nocardia are nonmotile filamentous bacteria related to mycobacteria may cause chronic infection of skin and soft tissues may cause chronic infection of skin and soft tissues Actinomyces sp – responsible for diseases of the oral cavity & intestines Actinomyces sp – responsible for diseases of the oral cavity & intestines Nocardia brasiliensis causes pulmonary disease similar to TB Nocardia brasiliensis causes pulmonary disease similar to TB

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