1. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation prepared by Christine L. Case M I C R O B I O L O G Y a n i n t r o d u c t i o n ninth edition TORTORA  FUNKE  CASE Part A 25 Microbial Diseases of the Digestive System

2. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Microbial Diseases of the Digestive System  Transmitted in food and water  Fecal-oral cycle can be broken by  Proper sewage disposal  Disinfection of drinking water  Proper food preparation and storage

3. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings The Digestive System Figure 25.1

4. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Normal Microbiota  >700 species in mouth  Large numbers in large intestine, including  Bacteroides  E. coli  Enterobacter  Klebsiella  Lactobacillus  Proteus

5. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Dental Caries Figure 25.3

6. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Tooth Decay Figure 25.4

7. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Periodontal Disease Figure 25.5

8. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Bacterial Diseases of the Lower Digestive System  Symptoms usually include diarrhea, gastroenteritis, and dysentery.  Are treated with fluid and electrolyte replacement.  Infection is caused by growth of a pathogen:  Incubation is from 12 hours to 2 weeks.  Intoxication caused by ingestion of toxin:  Symptoms appear 1 to 48 hours after ingestion

9. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Staphylococcal Food Poisoning  Staphylococcus aureus enterotoxin is a superantigen. Figure 25.6

10. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Shigellosis  Shigella spp. producing Shiga toxin  Shiga toxin causes inflammation and bleeding. Figures 25.7, 25.8

11. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Salmonellosis  Salmonella enterica serovars such as S. typhimurium  Mortality (<1%) due to septic shock caused by endotoxin Figure 25.9

12. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Salmonellosis and Typhoid Fever Incidence Figure 25.10

13. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Calculate the Relative Risk to Determine the Most Likely Source of Salmonella FoodExposedNot Exposed Ill (a)Not ill (b)Ill (c)Not ill (d) Chicken salad4740613 Cole slaw32202133 Fruit salad34301923 Potato salad42391114 Tomato salad4724629 e = f = Relative Risk = a a + b c c + d efef

14. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings What Was the Most Likely Source of This Outbreak of Salmonella? FoodRelative Risk Chicken salad1.71 Cole slaw1.58 Fruit salad1.17 Potato salad1.18 Tomato salad3.86

15. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Typhoid Fever  Salmonella typhi  Bacteria is spread throughout body in phagocytes.  1 to 3% recovered patients become carriers, harboring Salmonella in their gallbladder.

16. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cholera  Vibrio cholerae serotypes that produce cholera toxin.  Toxin causes host cells to secrete Cl –, HCO –, and water. Figure 25.11

17. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Noncholera Vibrios  Usually from contaminated crustaceans or mollusks  V. cholerae serotypes other than O:1, O:139, and eltor  V. parahaemolyticus  V. vulnificus