1. Microbes and Humans Chapter 27

2. Microbes on Us β-Hemolytic Bacteria on Blood Agar…. streak from throat swab. We have many bacteria on us: mutualistic, commensal and potentially pathogenic. We are COLONIZED !! It is all based on our SURFACES.

3. Loose Association-Adhesion-Invasion

4. Each Surface Has Different Microbes *

5. We have lots of Bacterial Symbionts

6. Skin

7. Human Skin Where’s the Bacteria ?? After all there are 10 12 on the average human: where?.... 10 4 to 10 6 bacteria/sweat gland

8. Histological Section of Human Skin

9. Propionibacterium acnes

10. Skin Microbes Sweat: 0.2 to 1% solutes: minerals, lactate, urea. Can loose 100mL to 8L/day. Sebum: oils and waxes.

11. Oral and Nasal Cavities

12. Mouth

13. Dental Plaque

15. Dental Caries: Streptococcus mutans *

16. While the teeth have plaque, the gums are diseased

17. Human Gastrointestinal Tract

18. One of the Few in the Stomach *

19. SEM Mouse Columnar Epithelium: IIeum *

20. Normal daily gas production: 470 to 1,400 mL/day. In 8 – 20 episodes (5 mL to 375 mL/episode)

21. Feces are Mainly Bacteria *

22. Probiotics: Adding Live Bacteria to Your Intestine Bifidobacterium Lactobacillus

23. Probiotics: Lactic Acid Bacteria Bifidobacterium Lactobacillus acidophilus

24. Bacteroides Infection: Surgical Gas Gangrene Result of an unfortunate bowel surgery.

26. Trachea Epithelial Surface: The Escalator Only Goes Up *

27. Human Urogenital Tract Micrograph: vaginal swab, Gram stain. *

28. Virulence and Pathogenicity

29. Virulence: LD 50

30. Attachment Vibrio cholerae (pili) Escherichia coli (capsule)

32. Bacillus anthracis Glistening Mucoid Colonies Fluorescent Antibody B. anthracis capsule stain.

33. Streptoccus pneumoniae + E. coli *

34. Do We Got toxins !

35. Type of Exotoxins: Cytolytic Toxins Streptococcus pyogenes Clostridium perfringens producing lecithinase on egg yolk agar. Lecithin = phosphotidyl choline a membrane phosphoglycerol lipid

36. Type of Exotoxins: AB Toxins What is ADP-ribosylation?

37. Type of Toxins: AB Toxins Cholera Toxin: ADP Ribosylation of G-protein turning on Adenylcyclase.

38. Types of Exotoxins: Endo-Proteases *

39. Types of Exotoxins: Endoproteases

40. Endotoxin: LPS Limulus amoebocytes – degranulate (and lyse) in presence of LPS