Foodborne and Waterborne Bacterial Diseases

2. Foodborne and Waterborne Bacterial Diseases • Intoxications • Botulism • Staphylococcal food poisoning • Clostridial food poisoning • Infections • Typhoid fever • Salmonellosis • Shigellosis • E. coli diarrheas • Peptic ulcer disease • Campylobacteriosis • Brucellosis • Cholera • Bacillus cereus • Others

3. Portal of Entry – Mouth  G.I. Tract • Intoxications - illnesses in which bacterial toxins are ingested with food and water • Infections - illnesses in which live bacterial pathogens are ingested and grow in the body

4. The incubation period is the time between • consumption of contaminated material • appearance of symptoms • Clinical symptoms and duration of illness depend on: • the toxin or microbe (what it is) • the infectious dose (how much you ate) • Demographics can make individuals more or less prone to food/waterborne illness • For example, age or sanitary conditions • We usually lose the “bookends” – the vy young and the vy old. With so many opposite characteristics, what do these 2 different groups have in common?

5. The Problem:Contact with Fecally Contaminated Food and Water Ex: Ritual Bathing in the Ganges Sewage Meets Ganges

6. There Are Several Ways Foods or Water Become Contaminated • Meat can be infected during improper slaughter procedure • Fruits and vegetables can be washed with contaminated water • Infected humans can contaminate food they handle through the fecal-oral route

7. Cross-contamination can occur: • between foods • via knife, cutting board, etc. • Water contamination can occur by defecation of infected individuals in public water sources • Improperly stored foods can contain large numbers of pathogens because of rapid multiplication Figure 10.3, page 283

8. Foodborne Intoxications • Bacterial Food Poisoning Can Result from an Intoxication Botulism • Clostridium botulinum is the source of botulism • C. botulinum produces a deadly exotoxin that attacks the nervous system, causing flaccid paralysis • Death is caused within 1-2 days of symptom onset by respiratory paralysis

9. Symptom of Botulism: Flacid Paralysis

10. If treated early, large doses of antitoxins can neutralize the toxin • Most outbreaks are related to home-canned foods or from foods eaten cold (heat destroys the toxin) • Wound botulism occurs when a wound is infected with C. botulinum • Infant botulism, a.k.a floppy baby syndrome, frequently occurs when an infant is fed honey • Minute doses of botulinum toxin can be used to treat movement disorders and to remove facial wrinkles

11. Symptoms start ~ hours 1 ½ days after eating food • 7 strains AG – we are most affected by A,B & E • In U.S, around 100 cases /year • U.S., Germany began weaponizing toxin in WWII, Iraq deployed missiles filled with botulinum toxin in 1990. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2627746/pdf/10458954.pdf

12. Staphylococcal Food Poisoning • Staphylococcus aureus causes staphylococcal food poisoning • Toxins are often consumed in protein-rich foods such as: • meat and fish • dairy products • The enterotoxin causes gastroenteritis for several hours • Symptoms: nausea, vomiting and diarrhea starting at T+30min Figure 10.3a, page 283

13. Food is often contaminated by: • boils or abscesses on a handler’s skin • through sneezing • Proper handling, refrigeration, and heating help decrease the risk of contamination Figure 10.3b, page 283

14. Clostridial Food Poisoning • Clostridium perfringens • commonly contaminated are meat, poultry, and fish • Clinical symptoms require a high infectious dose, and take 8-24 hours to appear Figure 10.5, page 286

15. Foodborne and Waterborne Infections • Most GI infections require a large dose of bacteria; Shigella and E. coli O157 are exceptions Typhoid Fever • It is caused by Salmonella enterica serotype typhi (S. typhi) • S. typhiis transmitted by the five Fs: • Flies • Food • Fingers • Feces • Fomites Figure 10.6, page 287

16. S. typhi is acid resistant – can survive in sewage and the stomach • It passes through the stomach to the small intestine • It causes ulcers, bleeding, and pain • CNS symptoms – delirium, coma • Rose spots on the skin, not much diarrhea, but mucus and blood in the feces • Invasion into cardiovascular system can occur • Rose spots indicate blood hemorrhage • Vaccines contain dead or attenuated S. typhi or polysaccharides from S. typhi capsule – effective for ~ 2yrs.

17. Salmonellosis • Can Be Contracted from a Variety of Foods • Salmonellosis is usually caused by S. enterica serotype enteritidis or typhimurium • Gastroenteritis occurs 6 - 48 hours after a large infectious dose Figure 10.7b, page 290

18. Symptoms include, fever, nausea and/or vomiting, abdominal cramps, diarrhea, dehydration • Rarely fatal –(but you feel like you want to die!) • They can also be transmitted by live animals - milk • Chickens and reptiles can carry Salmonella – eggs also Figure 10.7a, page 290

19. Shigellosis (Bacterial Dysentery) • Occurs Where Sanitary Conditions Are Lacking • Shigellosis is primarily caused by Shigella sonnei • S. dysenteriae causes epidemics in the developing world • Contaminated foods commonly include: • Eggs • Vegetables • Shellfish • Dairy

20. An infectious dose requires as few as 10 S. sonnei individuals • Shiga toxin production in the intestinal epithelium destroys GI epithelial cells ulceration of the intestines  bloody stools • Infection of the large intestine can lead to fatal dysentery • ~18,000 cases/year in U.S. • No vaccine is available

21. Typhoid fever, Shigellosis, Campylobacteriosis are the main GI tract infections that cause bloody stools

22. Cholera • Causes dysentery = extremely watery diarrhea  enormous fluid loss • Cholera is caused by Vibrio cholerae • V. cholerae are often consumed with raw oysters and water • The cells are susceptible to stomach acid • A large infectious dose is needed to colonize the intestines Figure 10.8, page 291

23. Cholera

24. Dehydration - Tenting of Skin

25. Life Cycle of V. Cholerae

26. One Solution: Saris Folded 4 – 8 Times Can Filter Out Most Pathogens

27. Cholera toxin causes unrelenting loss of fluid and electrolytes through diarrhea (up to 1 L/hour) • In untreated, fluid loss leads to shock and coma • Can kill a healthy human adult in 3 days • Antibiotics and restoration of water and electrolyte balance are effective in treatment • Vaccines using dead V. cholerae are available • Immunity lasts for ~ 6 months

28. E. coli Diarrheas • Cause Various Forms of Gastroenteritis • Escherichia coli is normally found in the human intestine, but certain serotypes are pathogenic • “Travelers trots”, “Montezuma’s revenge”, infantile diarrhea, E. coli O157:H7 Figure 10.9, page 293

29. Enterotoxic E. coli (ETEC) produce a toxin that causes gastroenteritis – is noninvasive • a.k.a. traveler’s diarrhea, infantile diarrhea • Enteropathogenic E. coli (EPEC) cause diarrhea in infants, or particularly where sanitation is lacking – “moderately invasive” – symptoms caused mostly by inflammation, not toxins

30. Enterohermorrhagic E. coli(EHEC) is often transmitted by undercooked ground beef (or bagged spinach!) • O157:H7 – refers to surface identity markers • Contamination also occurs in unpasteurized milk and juice, sprouts, lettuce, and salami • Infection can occur from contact with cattle or swimming in/consuming contaminated water • A small infectious does causes hemorrhagic colitis 1-8 days after infection • Complications can occur in young children or the elderly, but most cases resolve in 5-10 days • Most serious complication is hemolytic uremia Figure 10.10, page 295

31. Gastric Ulcer Disease • Can Be Spread Person to Person • Helicobacter pylori • It is unknown how H. pylori is transmitted but it likely involves contaminated food or water – kissing??? • People can infect dogs?? • The bacteria produce urease, which in turn produces ammonia • Ammonia neutralizes acid in that area of the colony, allowing the bacteria to survive Microfocus 10.4b, page 296

32. The ammonia, and an H. pylori cytotoxin destroy mucous-secreting cells • This creates an ulcer • A urea breath test is used – detects radioactive CO2 coming from hydrolysis of urea NH3 C = O 2NH3 + CO2 NH3 Figure 10.11, page 297

33. Campylobacteriosis • Results from Consumption of Contaminated Poultry or Dairy Products; drinking from a stream • Campylobacteriosis is the most common cause of bacterial gastroenteritis in the U.S. • Campylobacter jejuni is transmitted through the fecal-oral route, usually by poultry Figure 10.12, page 298

34. Colonization of the intestine occurs during a 2-7 day incubation period • Guillain-Barré Syndrome is a rare nervous system disease that may develop

35. Listeriosis Usually Manifests Itself as Meningoencephalitis or Septicemia • Is caused by Listeria monocytogenes – a psychrophile • It is transmitted by: • food contaminated with feces • contaminated animal products like cold cuts and soft cheeses Figure 10.13, page 299

36. Listeriosis usually affects pregnant women, the elderly, or immunocompromised • Meningoencephalitis is characterized by: • headaches • stiff neck • delirium • Coma • Septicemia is a blood disease involving high numbers of infected monocytes • Infection of the uterus can occur in women – can cause mental retardation and developmental abnormalities in unborn children – a TORCH disease

37. Several Other Bacterial Species Can Be Transmitted through Food or Water • Brucella species cause brucellosis, which affects people who work with large ruminant animals • Infection can occur through eyes, abrasions, or consumption of contaminated dairy products • The bacteria are transported to the spleen and lymph glands upon infection, causing flu-like symptoms • Brucellosis is also called undulant fever because of a specific fever pattern

38. Vibrio species other than V. cholerae can cause illness • V. parahaemolyticus is a common problem where large amounts of seafood are consumed • V. vulnificus is transmitted by oysters and clams • It can cause a deadly systemic infection • Can also cause a “flesh-eating disease” • Found in Gulf coast waters

40. Bacillus cereus can cause diarrhea or vomiting • Infections usually occur from eating contaminated cooked grains • Produces a toxin that causes emesis • Can throw blood pH off • Plesiomonas shigelloides causes intestinal illness • Infection is often from eating raw seafood • Aeromonas hydrophila cause both cholera-like and dysentery-like diarrheas

41. Soap; Water; Washing Hands