Corynebacterium Erysipelothrix & Listeria

2. Corynebacterium Erysipelothrix & Listeria

3. Pathogenic Anaerobic Gram-Positive Bacilli

4. Corynebacteria (Genus Corynebacterium) ØAerobic or facultatively anaerobic ØSmall, pleomorphic (club-shaped), gram-positive bacilli that appear in short chains (“V” or “Y” configurations) or in clumps resembling “Chinese letters” ØCells contain metachromatic granules (visualize with methylene blue stain) ØLipid-rich cell wall contains meso-diaminopimelic acid, arabino-galactan polymers, and short-chain mycolic acids ØLysogenic bacteriophage encodes for potent exotoxin in virulent strains

5. Mycobacterium Nocardia Corynebacterium     Distinguishing Features of CMN Group

6. Pathogenic Corynebacterial Species • Corynebacterium diphtheriae • Corynebacterium jeikeium • Corynebacterium urealyticum

7. Corynebacterium urealyticum • ØUrinary tract infections (UTI’s); rare but important • ØUrease hydrolyzes urea; release of NH4+, increase in pH, alkaline urine, renal stones

8. Corynebacterium jeikeium • ØOpportunistic infections in immunocompromised (e.g., patients with blood disorders, bone marrow transplants, intravenous catheters) • ØMultiple antibiotic resistance common (MDR) • ØCarriage on skin of up to 40% of hospitalized patients (e.g., marrow t-plants)

9. Percentage of Individuals Colonized Corynebacterium jeikeium Carriers

10. Corynebacterium diphtheriae • ØRespiratorydiphtheria (pseudomembrane on pharynx) and cutaneous diphtheria • ØPrototype A-B exotoxin acts systemically • Toxoid in DPT and TD vaccines • ØDiphtheria toxin encoded by tox gene introduced by lysogenic bacteriophage (prophage) • ØSelective media: cysteine-tellurite; serum tellurite; Loeffler’s • ØGravis, intermedius, and mitis colonial morphology

11. Epidemiology of Diphtheria

12. Incidence of Diphtheria in the USA

13. Incidence of Diphtheria in Former Soviet Union

14. Virulence Factors in Corynebacterium Species

15. Diphtheria tox Gene in Beta Bacteriophage and Prophage

16. See Handout on Exotoxins

18. Mechanism of Action of Diphtheria Toxin: Inhibition of Protein Synthesis

19. Catalytic Region A Subunit B Subunit Translocation Region Receptor-Binding Region Molecular Structure of Diphtheria Toxin

20. Heparin-binding epidermal growth factor on heart & nerve surfaces

21. Immune Status to C. diphtheriae and Sensitivity to Diphtheria Toxoid TOXIN TOXOID Diagnostic Schick Skin Test

22. In vivo Detection of Diphtheria Exotoxin

24. Listeria monocytogenes • Gram-positive beta-hemolytic bacillus • Multiply at refrigerator temperatures (4oC) • Tumbling motility at room temperature • CAMP Test positive (like Group B Streptococcus)

25. Where do we find Listeria? • Intestinal tract of mammals & birds (especially chickens) • Persists in soil • Soft cheeses & unwashed raw vegetables • Raw or undercooked food of animal origin • Luncheon meats • Hot dogs • Large scale food recalls have become common

26. Epidemiology of Listeriosis

27. Natural Reservoirs Common Routes for Human Exposure Population at Greatest Risk Epidemiology of Listeria Infections

28. Listeriosis • Neonates, elderly & immunocompromised • Granulomatosis infantiseptica • Transmitted to fetus transplacentally • Early septicemic form: 1-5 days post-partum • Delayed meningitic form: 10-20 days following birth • Intracellular pathogen • Cell-mediated and humoralimmunity develop • Only cell-mediated immunity is protective

29. Methods That Circumvent Phagocytic Killing See Chpt. 19

30. Intracellular Survival & Replication of Listeria Phagocytosis Macrophage Listeriolysin O? Macrophage Intracellular Replication Actin Filaments

32. Erysipelothrix rhusopathiae • Gram-positive non-motile bacillus; forms filaments • Occupational disease of meat and fish handlers, hunters, veterinarians • Preventable withprotective gloves & clothing • Erysipeloid in humans; erysipelas in swine & turkeys • Organisms enter through break in skin • Nonsuppurative, self-limiting skin lesions with erythema and eruption • Peripheral spread may lead to generalized infection, septicemia and/or endocarditis • Organisms can be isolated from skin biopsy

33. Epidemiology of Erysipelothrix Infection

35. REVIEW

36. Corynebacterium diphtheriae • ØRespiratorydiphtheria (pseudomembrane on pharynx) and cutaneous diphtheria • ØPrototype A-B exotoxin acts systemically • Toxoid in DPT and TD vaccines • ØDiphtheria toxin encoded by tox gene introduced by lysogenic bacteriophage (prophage) • ØSelective media: cysteine-tellurite; serum tellurite; Loeffler’s • ØGravis, intermedius, and mitis colonial morphology REVIEW

37. Diphtheria tox Gene in Beta Bacteriophage and Prophage REVIEW

38. See Handout on Exotoxins REVIEW

39. Mechanism of Action of Diphtheria Toxin: Inhibition of Protein Synthesis REVIEW

40. Corynebacterium jeikeium • ØOpportunistic infections in immunocompromised (e.g., patients with blood disorders, bone marrow transplants, intravenous catheters) • ØMultiple antibiotic resistance common (MDR) • ØCarriage on skin of up to 40% of hospitalized patients (e.g., marrow t-plants) REVIEW

41. Corynebacterium urealyticum • ØUrinary tract infections (UTI’s); rare but important • ØUrease hydrolyzes urea; release of NH4+, increase in pH, alkaline urine, renal stones REVIEW

42. Listeria monocytogenes • Gram-positive beta-hemolytic bacillus • Multiply at refrigerator temperatures (4oC) • Tumbling motility at room temperature • CAMP Test positive (like Group B Streptococcus) REVIEW

43. Natural Reservoirs Common Routes for Human Exposure Population at Greatest Risk Epidemiology of Listeria Infections REVIEW

44. Listeriosis • Neonates, elderly & immunocompromised • Granulomatosis infantiseptica • Transmitted to fetus transplacentally • Early septicemic form: 1-5 days post-partum • Delayed meningitic form: 10-20 days following birth • Intracellular pathogen • Cell-mediated and humoralimmunity develop • Only cell-mediated immunity is protective REVIEW

45. Intracellular Survival & Replication of Listeria Phagocytosis Macrophage Listeriolysin O? Macrophage Intracellular Replication Actin Filaments REVIEW

46. Erysipelothrix rhusopathiae • Gram-positive non-motile bacillus; forms filaments • Occupational disease of meat and fish handlers, hunters, veterinarians • Preventable withprotective gloves & clothing • Erysipeloid in humans; erysipelas in swine & turkeys • Organisms enter through break in skin • Nonsuppurative, self-limiting skin lesions with erythema and eruption • Peripheral spread may lead to generalized infection, septicemia and/or endocarditis • Organisms can be isolated from skin biopsy REVIEW