1. Staph, Strep, Cholera, & TSEs

2. Actions/Types of Bacterial Toxins
Invasins
Adhesins
Enzymes
Enzyme Inhibitors/activators
Membrane disruptors
Protein synthesis inhibitors
Siderophores
Immunological disruptors
And more.

3. Staphylococcus aureus
Causes:
Boils/Abscesses
Impetigo
Folliculitis
Scalded Skin Syndrome
Toxic Shock Syndrome
Endocarditis
Osteomyelitis
Septicemia
Surgical wound infections
Food poisoning
Pneumonia

4. Abscess

5. Scalded Skin Syndrome

6. Endocarditis

7. S. Aureus Toxins Alpha Toxin/Hemolysin Leukocidin Coagulase
Staphylokinase
Hyaluronidase
Protein A
Staph Enterotoxins(SE) (A-G)
Toxic Shock Syndrome Toxin (TSST)
Exfoliation Toxins

8. gsbs.utmb.edu/microbook/ch012.htm

9. Leukocidin from CA-MRSA
Target neutrophils
Alpha toxin targets monocytes & platelets.
Nature.com

10. Transduction of Leukocidin Production
Nature.com

11. Superantigen

12. Superantigens TSST-1 (Toxic Shock Syndrome Toxin)
Staph Enterotoxins A - G
Exfoliation toxin

13. Streptococcus pyogenes (Group A)
Causes:
Erysipelas
Necrotizing fasciitis
Streptococcal TSS
Scarlet fever
Pharyngitis (strep throat)
Puerperal fever
Rheumatic fever

14. b-Hemolysis
S. pyogenes

15. Step Throat

16. Erysipela

17. Necrotizing Fasciitis

18. Rheumatic Fever

19. Scarlet Fever

20. S. Pyogenes Toxins M proteins Hyaluronic acid Protein F Streptolysins
Hyaluronidase
Streptokinases
Streptodornases
Proteases
Streptococcal pyrogenic exotoxins (Erythrogenic toxin)

21. M proteins
Prevent phagocytosis.
Some resemble heart muscle proteins.

22. Hyaluronic Acid S. Pyogenes capsule Host connective tissue
Glucuronic acid N-acetyl-glucosamine

23. Recent UN Development Program Report
2.6B people lack proper toilets
At least 1B get water from sources polluted with human or animal feces
$10B estimate to halve the above numbers
“Beyond Scarcity: Power, Poverty and the Global Water Crisis”

24. Cholera Vibrio cholerae
Survive in estuaries (high salt) and fresh water; tolerant of alkalinity
Spore-like state – not culturable, but infectious
Two known serotypes (other serotypes cause milder disease)
Grow in small intestine

25. Cholera Host cells lose chlorides, bicarbonates and water
3-5 gallons can be lost per day; massive diarrhea
Blood becomes viscous
Rehydration is best therapy

27. Vibrio cholerae along
Brush border of rabbit villi

31. Virstatin turns off transcription of an exotoxin and a pilus
Virstatin inhibits virulence expression in V. cholerae
Virstatin turns off transcription
of an exotoxin and a pilus
Exotoxin (Cholera toxin) is an
enzyme that elevates cAMP in
host cells – leads to fluid loss
(gene is part of prophage)
Pilus is for attachment
Virstatin can inhibit cholera infection in mice
D. T. Hung et al., Science 310, (2005)
Published by AAAS

32. Unusual Quorum Sensing
In some strains of V. cholerae, QS works the opposite of expectations.
High concentration of autoinducer inhibits toxin production!

33. Cholera Epidemic in Iraq
1217 cases in Northern Iraq from August – December, 2007.
Sulaymaniya province.
Meeting 27.5% of water demand.
SF Chronicle. 12/10/07.
(16,000?)

34. Cholera in Haiti, 2010 – 2011 6742 cases as of Nov. 3, 2010
442 dead as of Nov. 3, 2010
Brought by foreign peace keepers?
Could now be endemic.
Update: 285,931/4870 as of April 17th.
473,649/6631 as of Oct. 14th.
paho.org

35. Other Bacterial Toxins
Shiga toxin.
Botulinum toxin.
Tetanospasmin.
Pertussis toxin.
Diphtheria toxin.
Endotoxin.

36. Transmissible Spongiform Encephalopathies (TSEs)
Caused by prions – clumps of abnormally folded proteins
Prions can “recruit” normal proteins to form prions
Incubation times are usually many years following ingestion of infected meat
Destroys brain tissue
Sheep, deer, elk, cows, humans
Prions cannot be destroyed by cooking (they are already “cooked”)

37. Prion Protein Structure

38. Prion Formation

39. Chronic wasting disease in deer and elk
Scrapie in sheep
Mad cow disease (bovine spongiform encephalopathy) in cows

40. BSE

41. Human TSEs Creutzfeldt-Jakob disease (CJD) – Cerebrum, thalamus
vCJD = thalamus, cerebellum
Possible connection to mad cow disease is feared
Kuru – primarily in New Guinea (related to practice of eating the dead); cerebellum

42. Mad Cow Disease Bovine Spongiform Encephalopathy (BSE)
Probably arose from practice of feeding cows other animals (esp. sheep and then infected cows)
Huge outbreak in Great Britain in mid 1990s
Found in Canada and U.S. in 2003

43. Transmission Definitely through consumption of brain tissue
What about other tissues?
Found in blood, urine, and other tissues in mice and deer (recent studies)

44. Other Possible Human Prion Diseases
Alzheimer’s.
Parkinson’s.
Huntington’s.
Amyotrophic Lateral Sclerosis.