FOOD SAFTEY MIDTERM

What are the primary food safety hazards?

Biological

Chemical

Physical

Allergenic

What is a food pathogen?

Microbes found in animals and in the environment that make people sick regardless of how they were infected

How do we get infected by food pathogens

Infection by ingestion and contact with Individuals/animals/pets

What are the types of food pathogens?

Bacteria

Virus

Parasites

biological hazards-Prions

Other hazards causing foodborne illness

how many people are affected by food borne illness (FBI) in Canada?

1 in 8 Canadians (4 million)

what are Canada's common culprits for FBI?

Norovirus

Listeria

Salmonella

e.coli

campylobacter

How do we estimate FBI cases?

Canadian Notifiable Disease Surveillance System

National Enteric Surveillance Program

National Studies on Acute Gastrointestinal Illness

FoodNetCanada

Common causes of food borne illness

Improper cooking

Improper storage (cooling)

Cross-contamination

Improper hot holding

Improper reheating

Preparation too far in advance

Raw ingredients

Infected person

How do we stop bacteria from growing (hint: FATTOM)

control 1 or more

1. Food

2. Acid

3. Temp

4. Time

5. Oxygen

6.Moisture

What do Intrinsic and extrinsic factors do?

Prevent or limit growth

What are Intrinsic factors?

inherent to food

(e.g water activity - aw, ph temp)

What are extrinsic factors?

external conditions

(e.g. temp and relative humidity)

At what pH do most microorganisms grow best?

7.0 (6.5-7.0)

Few microorganism's grow below what pH?

4.0

Most microorganism's are what?

Most are neutrophils

What foods fall below the point at which bacteria normally grow?

Anything pickled in brine , some soft drinks and wines

How can water activity be controlled to preserve food?

drying = removal of moisture

What is water activity (aw)

water that is not bound physically by solutes or to surfaces and is available for microorganisms

what aw do microorganisms require?

at least 0.90

What happens when you increase the temperature or food?

Hint: aw

Aw increases

What is the AW for most fresh foods?

aw greater than 0.99

What does it mean when there is a lower AW

increase the lag phase of bacterial growth

What is the Oxidation-reduction potential

ease with which food loses or gains electron

Aerobic organisms

require oxygen for growth

Anaerobic organisms

can survive without oxygen

Microaerophilic

can grow best under reduced conditions

Facultative anaerobe

can grow with or without oxygen

At what tempreture does Pathogenic bacteria grow best?

body temperature (37C)

what are the Three groups of pathogenic bacteria

1)Psychrotolerant: tolerate but don't grow best in the cold

2)Mesophiles: between 20-40 deg

3)Thermophiles: high temps - 41-122 deg

What temperature should we keep food to prevent growth?

below 4 or higher than 60

what temp should food be reheated to?

74 degC

what temp should food be thawed at?

40 degC

Does freezing kill bacteria?

bacteria inactive, but nothing is actually killed

How long can I keep canned foods and dry foods?

no time limit if the product is in good condition

What is the issue with bulging or dented cans?

Dent can mean that the seal Is no longer tight

Gasses can indicate bacteria inside

what is the The Danger Zone-time/temperature

4 C -60 C

2 hours

At what temp is bacteria killed

greater then 60 C

What are some examples of hazardous foods?

- Meat, fish (shellfish), poultry , Eggs, Dairy

protein rich foods

Fresh cut or peeled fruits and vegetables

Cooked veggies, rice, pasta, Sprouts

How protect food from the danger zone?

Arrange shopping so quick to fridge

Thaw foods in fridge, cold running water or microwave

use thermometer

Cool quickly; reduce large volume into smaller portions using shallow pans

What are the growth factors for (FATTOM) - FOOD?

Access of microorganism to food

- food product & cleanliness of environment

What are the growth factors for (FATTOM) - ACID?

ph of food

What are the growth factors for (FATTOM) - time?

amount of time microorganism have to grow

- how long in danger zone

What are the growth factors for (FATTOM) - temp?

danger zone : 4-60 deg cel

What are the growth factors for (FATTOM) - Oxygen

amount of oxygen avalible to microorganism

- aerobic or anaerobic

What are the growth factors for (FATTOM) - moisture

Aw (water activity) of food

7 principles of HACCP

1)Hazard analysis

2)Identifying critical control points (CCPs)

3)Establishing critical limits for each CCP

4)Establishing monitoring procedures for CCPs

5)Establishing corrective actions

6)Establishing verification procedures

7)Record keeping

What is one limitation of the infrared (laser) thermometer?

Because it only measures surface level temp not the internal temp

To what temp should food be reheated?

74c

What is one benefit of a thermocouple thermometer over a thermistor thermometer?

Thinner probe, quicker results

What is a microaerophilic organism?

Does require oxygen for growth but at lower concentrations than what is present in atmosphere

What is the name of the type of thermometer that can be used only once and is intended to indicate the final cooking temperature of a turkey?

Pop up timer

Single use indicator

We shouldn't be using b/c they pop up too quickly

Which type of organism can multiply over the widest PH range?

molds

According to Public Health Ontario (PHO), where do most foodborne outbreaks occur in Ontario? Followed by?

In the homes

Followed by restaurants

Name two ways to rapidly cool a whole chicken

Separate into smaller or thinner portions

Put it in a shallow pan

Why would the water activity of a food never be measured as 0?

Aw scale goes from 0-1

Most foods will have some type of water activity

What do you think is premature browning?

When you are cooking something, and it looks like its cooked but its not reached proper internal temp

What are the main differences between gram negative and gram positive bacteria?

cell wall and dystanin

is also more resistant, has resistant qualities

What are the main differences between sporing and non-sporing bacteria?

Spores are more resistant to heat, cold freezing, chemicals

Spores can survive harsher conditions

What are biofilms?

slimy layers of microorganisms that stick to wet surfaces

Frequent source of infection

How to prevent biofilms in food?

1)Disinfection in time

2)Disinfection of biofilm

3)Inhibition of microbes via surface selection

What is an infection?

Microorganism invades and multiplies in the body

Intestine is damaged or invaded by pathogens

What is an intoxication?

Illness caused by the ingestion of microbial toxins produced in foods prior to consumption

Toxin pre-formed in foods

Toxin produced after consumption

What are the types of Intoxications?

Endotoxin (Toxins present in the outer membrane of the cell, G-)

Exotoxin (Highly toxic proteins produced during multiplication or sporulation, G-)

Enterotoxin (Toxin released in the intestine that specifically affect the host intestinal mucosal cells)

Serotyping

Serotyping is different than serology

Sub typing test

Serotypes are groups within a single species of a microorganism

PFGE PATTERN

laboratory technique to produce a DNA fingerprint for a bacterial isolate

Whole Genome Sequencing (WGS)

laboratory technique that determines the order of bases (A, T, C and G) in the genetic material (genome) of an organism

new gold standard for finger printing

What are the general characteristics of salmonella?

Small

gram negative,

non-sporing rods

Is salmonella widely distributed in nature

yes

What are the primary reservoirs of salmonella

Animals and Humans

What are the two species of salmonella?

S. enterica*

S. bongori

How can we stop S. enterica?

Easy kill step (cooking food)

Which one is of greatest public health concern when it comes to Salmonella enterica?

Septicemia - when it gets into your blood

two sub types of Salmonella enterica

Non typhoidal

typhoidal

Salmonellosis (nontyphoidal) - Infectious does

As low as one cell

Low infective dose

Salmonellosis (nontyphoidal) - illness type

infection

Salmonellosis (nontyphoidal) - Route of transmission

Fecal -oral

Secondary transmission is possible

Asymptomatic carriers

Salmonellosis (nontyphoidal) - Incubation Period

6-72H

Salmonellosis (nontyphoidal) - Duration of illness

4-7days

Acute = 1-2 days

Salmonellosis (nontyphoidal) - Mortality

1% higher for s.enteritidis in hospital/LTC

CFR: 0.3%

Salmonellosis (nontyphoidal) - Diagnosis

Fecal sample

Salmonellosis (nontyphoidal) - Treatment

self limiting

Supportive treatment for dehydration

what is the leading reportable enteric disease in Ontario

campylobacteriosis

followed by Salmonellosis

Is Salmonellosis a notifiable disease in Canada?

yes

Is Salmonellosis a reportable disease in Ontario?

yes

What are the foods associated with Salmonellosis (non typhoidal)

Contaminated from feed, infected animals and environment

Cross-contamination of cooked ready to eat foods

Processed foods

Salmonella in Animals

Most are asymptomatic carriers

Via infected animal or contaminated feed or water

Many outbreaks linked to hatcheries

What are the reported risk factors for Salmonellosis in Ontario?

travel

contact with animals

consumption of raw or undercooked poultry or eggs, unwashed fruits and vegetables, contaminated water

What are the preventive measures for Salmonellosis?

Separate raw foods from cooked foods, kitchen surfaces, utensils, and dinnerware, etc.

wash produce

Refrigerate eggs promptly

HACCP plan

Do not cook when ill

Typhoid Fever (paratyphoid) - infectious dose

Fewer than 1K cells

Low infective dose

Typhoid Fever (paratyphoid) - illness type

infection

Typhoid Fever (paratyphoid) - route of transmission

Fecal Oral,

Contaminated water, food

Secondary transmission

Typhoid Fever (paratyphoid) - incubation period

1-3 weeks

Typhoid Fever (paratyphoid) - duration of illness

2-4 weeks

Typhoid Fever (paratyphoid) - mortality

10% if untreated

CFR= 0

Typhoid Fever (paratyphoid) - diagnosis

stool, urine, blood

Typhoid Fever (paratyphoid) - treatment

self limiting

supportive treatment for dehydration

Typhoid Fever (paratyphoid) - symptoms

gastrointestinal symptoms;

A rash of flat, rose coloured spots sometimes occurs

Typhoid Fever (paratyphoid) - complications

septicemia, endocarditis, chronic infections

is Typhoid Fever a reportable disease

yes

is Typhoid Fever a notifiable disease

no