Bacterial Foodborne Diseases Flashcards Preview

RUSVM Epidemiology > Bacterial Foodborne Diseases > Flashcards

Flashcards in Bacterial Foodborne Diseases Deck (49)
1

bacterial foodborne infections caused by:

intoxication
infection

2

bacteria associated with intoxication:

Staphylococcus aureus
Bacillus cereus
Clostridium botulinum
Clostridium perfringens

3

bacteria associated with infection

Campylobacter jejuni
Salmonella spp.
Escherichia coli
Vibrio spp.
Listeria monocytogenes

4

2 ways bacterial toxins are named

by type
by target tissue

5

endotoxins

gram +
staph, bacillus, clostridium

6

exotoxins

gram -
campylobacter, salmonella, E. coli, Vibrio

7

typical symptoms: intoxication

Onset is usually rapid: 30min‐6hrs most commonly, but up to 12 hrs
Illness usually lasts for ~1‐2 days
The primary exception is botulism toxin
(neurotoxin)

8

typical symptoms: infection

Onset in several hours, to days
Illness usually lasts for several days
Many produce enterotoxins that cause watery diarrhea, ranging from mild to severe
Invasive species, or species with toxins that kill enterocytes, cause dysentery, fever, and possibly septicemia

9

Staphylococcus aureus: reservoir

skin and nose of many healthy people

10

Staphylococcus aureus: transmission

Vehicle: food: contaminated with S. aureus
and stored at temperatures favorable to growth and toxin production (danger zone: 40-140 F)

11

Staphylococcus aureus: clinical signs

Most common foodborne intoxication
rapid onset (30min-6hrs)
Vomiting, diarrhea, cramping
+/- 24hrs

12

Staphylococcus aureus: prevention

proper food hygiene and storage

13

Bacillus cereus: reservoir

soil

14

Bacillus cereus: transmission

Vehicle: food, contaminated with bacteria or
spores and stored at temperatures favorable to growth and toxin production (rice and grains!!)

15

Bacillus cereus: clinical signs 2 forms

“Enteric Form” Nausea and vomiting
Incubation period 30 minutes to to 6hrs
“Diarrhea form” diarrhea and cramping
Incubation period 8‐16 hrs

16

Bacillus cereus: prevention

proper food hygiene and storage

17

Clostridium botulinum: reservoir

Soil; sediments (stream, lake, and coastal waters); intestinal tracts of fish and mammals; gills and viscera of crabs and shellfish; honey

18

Clostridium botulinum: transmission

Vehicle: food contaminated with spores at
production and then improperly processed
allowing growth and toxin production

19

Clostridium botulinum: clinical signs (neurotoxin)

flaccid paralysis
small infective dose
onset 18-36hrs
infant botulism (under 1 year)

20

Clostridium botulinum: prevention

Avoid contamination of food
Don’t feed honey to children less than 12 months of age
Proper preparation of food

21

Clostridium perfringens: reservoir

Soils, sediments, intestinal tracts of people and animals

22

Clostridium perfringens: transmission

Vehicle: foods contaminated at production, processing or preparation

23

Clostridium perfringens: clinical signs

Incubation period 8‐22 hrs
Vomiting, diarrhea, abdominal cramps
Duration 24 hrs

24

Clostridium perfringens: prevention

proper food processing and preparation

25

preventing foodborne intoxication

Proper food hygiene
Proper food preparation and storage
Proper canning
Meat hygiene

26

True/False: Campylobacter jejuni is more prevalent in the summer

true: picnics

27

Campylobacter jejuni: reservoir

Normal component of intestinal flora of many species
Many bird species
Many mammalian species can be infected

28

Campylobacter jejuni: transmission

C. jejuni is very fragile
Vehicle is contaminated food, water
Very low infectious dose
Direct contact with farm animals

29

Campylobacter jejuni: clinical signs

Incubation period: 2‐5 days
Infection and enterotoxin production
Duration of symptoms: 7 days (2‐10 days)

30

Campylobacter jejuni: prevention

target the vehicle:
– OFFS: reduce infection in birds going to slaughter
– Meat hygiene
– Pasteurization of milk
– Proper handling and cooking of meat esp poultry

31

Salmonella spp: reservoir

GI flora in many species (birds, cattle, rodents, etc.)
skin flora in reptiles

32

Salmonella spp: transmission

many foods

33

Salmonella spp: clinical signs

Incubation period: 12‐72 hours
An invasive type infection
Duration of symptoms: usually 4‐7 days

34

Salmonella spp: prevention

many strategies
pre-harvest: OFFS
post-harvest: hygiene, pasteurization, cook foods properly, education

35

Salmonella Enteritidis

Causes egg‐associated salmonellosis
Associated with eating raw or undercooked eggs

36

E. coli: reservoir

found in many mammalian species
varying pathogenicity

37

E. coli: transmission

Vehicle: contaminated food
Carcasses contaminated in plant, veggies irrigated with contaminated water, unpasteurized milk, cheese, fruit juices

38

E. coli: clinical signs (O157H7)

Incubation period: 3‐4 days
Infection + enterotoxin (Shiga toxin) production
Duration of symptoms: 5‐7 days
5-10%: hemolytic uremic syndrome

39

E. coli: prevention

many different strategies
pre-harvest: OFFS, vaccination
post-harvest: hygiene, pasteurization, cook food properly

40

true/false: most cases or E. coli are seen from outbreaks

true

41

Vibrio cholerae: reservoir

People, naturally found in brackish rivers and coastal waters

42

Vibrio cholerae: transmission

water: most important
transmission: contaminated by water

43

Vibrio cholerae: clinical signs

Very important world wide
Infection + enterotoxin = VERY watery diarrhea

44

Vibrio cholerae: prevention

Sanitation, sewage management and water treatment
Food preparation: Proper handling and cooking of food especially shellfish, wash fruits and veggies

45

Listeria monocytogenes: reservoir

soil, water, animals

46

Listeria monocytogenes: transmission

vehicle: infected food
replicates at low temperatures (low as 3C)

47

Listeria monocytogenes: clinical signs

Causes mild food poisoning, or flu‐like symptoms, in most exposed people
– No toxin production
– Septicemia and meningitis
– Abortions

48

Listeria monocytogenes: prevention

Meat hygiene
Pasteurize milk
Food preparation: Cook food fully, wash fruits and veggies

49

prevention of foodborne infection

Target the vehicle: no toxins produced in food
-OFFS
-meat hyigene
-pasteurization (capy, salmonella, E. coli, listeria)
-proper handling and cooking of food
-sewage management (Vibro cholera)