Corynebacterium, Listeria, and Erysipelothrix are pathogenic gram-positive bacilli. Corynebacterium diphtheriae causes respiratory diphtheria and is transmitted via lysogenic bacteriophage. Listeria monocytogenes causes listeriosis and is an intracellular pathogen that uses actin-based motility to spread between host cells. Erysipelothrix rhusiopathiae causes erysipeloid in humans through breaks in the skin from occupational exposure to meat and fish.

1. Corynebacterium Erysipelothrix & Listeria

2. Pathogenic Anaerobic Gram-Positive Bacilli

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

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

8. Epidemiology of Diphtheria

9. Virulence Factors in Corynebacterium Species

10. Diphtheria tox Gene in Beta Bacteriophage and Prophage

11. See Handout on Exotoxins

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

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

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

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

17. In vivo Detection of Diphtheria Exotoxin

18. 2. Genus Listeria

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

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

34. Epidemiology of Listeriosis

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

37. Methods That Circumvent Phagocytic Killing See Chpt. 19

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

40. Epidemiology of Erysipelothrix Infection