Lecture 17: Waterborne and Foodborne Diseases Flashcards Preview

BIO 425: Microbiology > Lecture 17: Waterborne and Foodborne Diseases > Flashcards

Flashcards in Lecture 17: Waterborne and Foodborne Diseases Deck (31)
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1

What are the characteristics of waterborne and foodborne diseases?

bacterial pathogens that cannot be eliminated

Reservoir is food/water and not transmitted from human to human

2

What kinds of epidemics can food/waterborne diseases cause?

common source epidemics

3

What is the single most important factor for public health?

Clean water w/ no iological/chemical contamination

4

What is monitored in maintaining water quality?

Chemicals, radioactive substances, microorganisms

5

What is GenX?

Industrial chemical used in teflon
produced by chemours (DuPont) companies

6

GenX is unregulated y EPA, what is the criteria for regulation?

1. Adverse effect on public
2. High risk to occur in public H2O

7

How are we studying GenX in Wilmington?

Cross sectional study w/ 400 residents

Measuring:
1. Blood and urine
2. Household drinking water
3. PFAS

8

What are some water purification methods?

Filtration
-effective + expensive

Chlorination
-effective + inexpensive

9

How do we monitor microorganisms when monitoring water?

Look for Fecal Coliforms
-bacteria present in intestines of humans
-indicator of water contamination not quality

Coliform Cultures

10

What are the rules of the revised total coliform rule for monitoring water quality?

1. Sites representative of system
2. Collection occurs at regular time intervals
3. Number of collections depends on population size
4. Each positive result is retested

11

What are some waterborne diseases?

Drinking water outbreaks
-contaminated drinking water

Recreational water outbreaks
-contaminated pools and lakes

12

What is cholera?
-pathogen

waterborne disease
pathogen - vibrio cholera

13

Is vibrio cholera Gram (+) or (-)? What is its reservoir?

Gram (-)
reservoir - coastal + marine habitats

14

What is the pathogenesis of cholera?

caused by ingestion of contaminated water
-attached to wall of small intestine and produces cholera toxin

15

How is cholera diagnosed?

presence of V. cholera cells in feces

16

How is cholera prevented?

Vaccine for some strains

maintain adequate sewage treatment and safe drinking water

17

How is cholera treated?

fluid replacement and antibiotics

18

What is legionnaires disease?
-pathogen
-gram (+) or (-)
-reservoir

waterborne disease
-pathogen: Legionella pneumophila
-gram (-)
-reservoir: lakes and streams

19

What is the pathogenesis of legionairres disease?

airborne transmission and infection in lungs
-mild infection = pontiac fever
-severe infection = pneumonia

20

How is legionairres disease diagnosed?

cultures from body fluids

21

How is legionairres disases prevented and treated?

air conditioning maintenance and hyperchlorination

Treated with antibiotics

22

What is the first line of defense against foodborne diseases?

food preservation

23

What are the major food categories?

1. perishable - fruit
2. semi-perishable - potatoes
3. nonperishable - flour

24

How do we reduce microbial growth on food?

1. Low temp - refrigeration
2. Low pH - pickling
3. Low water - drying
4. Low Oxygen - vacuum

25

What are chemical preservatives used for

increase shelf life and perceived quality of food

26

What are some other preservation methods for food?

High pressure processing
-pascualization
-high hydrostatic pressure kills microbes

Irradiation
-ionizing radiation kills microes

27

What is the difference between food poisoning and food infectIon?

Food poisoning
-ingestion of food containing microbial toxins
-immediate

Food Infection
-ingestion of food containing vialbe pathogens
-takes longer for symptoms to appear

28

What kinds of bacteria cause food poisoning?

Staphylococcus spp.
-produce enterotoxins
-reservoir=meat, poultry, cream

Clostridium spp
-C perfingens
-reservoir= raw meat
-most commons

-C botulinum
-improper garlic canning
-most dangerous

29

What are some treatment and prevention of food poisoning?

supportive treatment (fluids)

sanitation in food production

30

What bacteria cause food infection?

• Salmonella spp.
– Diverse virulence factors
– Severe Cases: Typhoid Fever
– Chronic Carriers: Typhoid Mary

• Camplyobacter spp. (most common)
– Resident in poultry intestines (90%)
– Treated with antibiotics for severe cases

• Listeria monocytogenes (Listeriosis, most severe)
– Psychrotolerant + common in prepackaged food
– Severe Cases: septicemia + meningitis