Microorganisms
are small, living organisms that can be seen only through a microscope.
Pathogens
microorganisms that can cause illness.
toxins
pathogens that make you sick.
An understanding of pathogens and the toxins that some produce is the first step in preventing food-borne illnesses.
The four types of pathogens that can contaminate food are;
Bacteria, viruses,fungi, and parasites.
-can cause illness without being seen, smelled or tasted.
-most pathogens get into food and onto food-contact surfaces because of the way that people handle them.
For example:
food handlers who do not wash their hands after using the restroom may contaminate food and surfaces with feces from their fingers.
once the food that the food handler touched is eaten, a food-borne illness may result.
This is called the fecal-oral route
Some pathogens are passed very easily in any of these ways:
from person to person
through sneezing or vomiting onto food or food-contact surfaces.
from touching dirty food-contact surfaces and equipment and then touching food.
Simple mistakes can result in contamination, for example:
allowing ready to eat food to touch surfaces that have come in contact with raw meat, seafood, and poultry can lead to contamination.
pests are a major source of disease.
storing food or cleaning p
Common symptoms of a food-borne illness are
Diarrhea
Vomiting
Fever
Nausea
Abdominal cramps
Jaundice ( a yellowing of the skin and eyes)
How quickly a foodborne illness symptoms appear in a person is known as?
the onset time of the illness.
The Big Six are?
1. Shigella spp.
2. Salmonella Typhi
3. Shiga toxin-producing E. coli
4. Hepatitis A
5. Norovirus
6.Non Typhoidal Salmonella
* these pathogens are often found in very high numbers in an infected persons feces and can be transferred to food easily.
food ha
Bacteria
-are single-celled, living microorganisms that can spoil food and cause food-borne illness.
- are responsible for a large number of food-borne illnesses.
knowing what bacteria are and how they grow can help you control them.
-bacteria can be found almost
Pathogens need six conditions to grow what are they? think of FAT TOM?
F ood
A cidity
T emperature
T ime
O xygen
M oisture
What is the range of the Temperature Danger Zone?
41 F - 135 F or 5c-57 C
TCS food supports growth of bacteria better than others this includes meat, poultry, dairy products, and eggs.
Acidity
Bacteria grow best in food that is neutral to slightly acidic (a pH of 7.5 to 4.6).
Bacteria grows best in little or no acid.
0 high aci
Common types of food and their pH:
Lemons and limes have a ph 1.8-2.4.
Tomatoes have a pH of 3.7-4.0
Mayonnaise has a pH of 3.8-4.0
Following groups have a pH that is ideal for bacterial growth:
Bread has a pH of 5.0-6.0
Raw chicken has a pH of 5.5-6.0
Ca
Bacteria Temperature
-grow more rapidly at 70F to 125F 21c-52C.
-Bacterial growth is limited when food is held above or -below the temperature danger zone.
Bacteria Time
-the more bacteria are in temperature danger zone more time they have to grow.
Bacteria Oxygen
-some need oxygen some do not.
-Bacteria that grow without oxygen can occur in cooked -rice, untreated garlic and oil mixtures, and temperature--abused baked potatoes.
Bacteria Moisture
-bacteria grow well with high levels of moisture.
-
The amount of moisture available in food for this growth is called?
water activity (aw)
-scale ranges from 0.0-1.0.
Food with a water activity of 0.85 or higher is ideal for the growth of bacteria.
To control time:
limit how long TCS food spends in the temperature danger zone.
To control temperature:
keep TCS food out of the temperature danger zone.
Bacterial growth can be broken into four progressive stages:
lag
log
stationary
death
Lag Phase:
bacteria that are introduced to food go through an adjustment period called lag phase. Their number is table as they get ready to grow. To prevnt food from becoming unsafe, prolong the lag phase by controlling the conditions for growth: temperature, time,
2. Log Phase
bacteria reproduce by splitting in two. Under the correct conditions, they can double as often as every 20 minutes. As a result, food will fast become unsafe.
-the time required for bacteria to enter a lag phase and grow in a log phase depends on FAT TOM
Stationary Phase
Bacteria can continue to grow until conditions become unfavorable. Eventually they grow and die at the same rate.
Death Phase
when drying bacteria outnumber growing bacteria, the population declines.
To keep from dying when they lack nutrients certain bacteria can change into a form called a ?
Spores.
0 often found in dirt
-they can contaminate meat, poultry, fish, and other food exposed to dirt or dust.
Spores can resist heat and survive cooking temperauters. They can also change back into a form that grows.
-you can prevent this by storing fo
Bacterial Growth Example:
Bacteria Growth
Number of Cells Time
1 Cell 0 Min
2 Cells 20 Min
4 Cells 40 Min
8 Cells 60 Min
16 Cells 1hr 20min
1 Billion Cells 10hrs.
Most bacteria need?
Oxygen to grow.
Bacillus cereus (bacteria)
Bacillus cereus gastroenteritis (illness)
-Is a spore forming bacteria found in dirt.
-produces two different toxins when allowed to grow to high levels.
-Toxins cause different illnesses.
Food Commonly Linked with Bacteria:
Cooked Vegetables
Meat Products
Milk
Most Common Symptoms:
watery diarrh
Bacteria Listeria monocytogenes (Bacteria)
Illness Listeriosis (Illness)
-is found in dirt, water, and plants.
-unlike most bacteria it grows in cool moist environments.
-is uncommon in healthy people but high risk populations are especially vulnerable particularly pregnant women
Food Commonly Linked with Bacteria
-Raw meat
-U
Enterohemorrhagic and shiga toxin-producing Escherichia coli (bacteria)
Hemorrhagic colitis (illness)
-found in the intestines of cattle/ also infected people.
-Bacteria can contaminate meat during slaughtering.
-Eating only a small amount of the bacteria can make a -person sick once eaten it produces toxins in the intestines which cause the illness.
-Bac
Campylobacter jejuni ( bacteria)
Camplyobacteriosis (illness)
-associated with poultry but also in contaminate water.
-Illness occurs when poultry is incorrectly cooked and when raw poultry has been allowed to cross-contaminate other food and food contact surfaces
-The pathogen is best controlled through correct coo
Clostridium perfringens (Bacteria)
Clostridium perfringens gastroenteritis (Illness)
found in dirt where it forms spores that allow it to survive.
carried in the intestines of both animals/humans
does not grow at refrigeration temperatures
grows rapidly in food in temperature danger zone.
commercially prepped food is not often in outbreak
Clostridium botulinum (Bacteria)
Botulism (Illness)
-forms spores that are often found in water/dirt.
spores can contaminate any food.
-bacteria does not grow well in refrigerator or highly acidic food or low moisture.
-grows without oxygen and can produce a lethal toxin when food is time-temperature abuse
Salmonella spp. (Bacteria)
Salmonellosis (Illness)
-farm animals carry Salmonella naturally.
-eating small amount can get you sick.
-severe symptoms depends on the health of the person and the amount of bacteria eaten.
-persons feces for weeks after symptoms have ended.
Food Commonly Linked with the Bacte