Final food contamination
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Transcript of Final food contamination
Prevention Of Food Contamination By Pathogenic
Microorganisms
Dr: Dina Ramadan LithyMicrobiology specialist central health laboratory
Cairo . Egypt
Pathogenic Microorganisms Very small ,Single cell organisms, seen by Very small ,Single cell organisms, seen by
microscope only.microscope only.
Eating or drinking food that contains harmful Eating or drinking food that contains harmful microbes can cause food poisoning.microbes can cause food poisoning.
NotNot all food all food APPEARINGAPPEARING normal normal is safeis safe to eat, it to eat, it may be contaminated by harmful bacteria which may be contaminated by harmful bacteria which cause food borne illness cause food borne illness
Apr 10, 20232
Microbiological pathogens
Food poisoning
Infective food poisoning Toxic food poisoning
Some bacteria produce toxins ,these toxins cannot be removed or inactivated by cooking.
Examples Staphylococcus aureus, Clostridium perfringens
Occurs as a result of eating food contaminated with bacteria itselfExamples; Salmonella, Listeria and Escherichia
coli .
Common Food borne Bacteria
Salmonella
one of the most common causes of food poisoning. Symptoms last 4-7 days without treatment. Salmonella is killed by cooking and pasteurization, But it can contaminate the food processing area
and transmitted to another food item.
Source Raw poultry and eggs Undercooked poultry and meat
Apr 10, 20235
Staphylococcus aureus
It is commonly found on the skin , hair ,
noses and throats of people and animals. It can multiply quickly at room
temperature and produce a toxin
that causes Food poisoning
Source ; Salads, macaroni Bakery products, cream pies,
and chocolate éclairs Milk and dairy products, Apr 10, 20236
EHEC (Enterohemorrhagic E. coli)
E. coli (0157:H7)Lives in intestines of healthy cattle It produce enterotoxin causes hemolytic
inflammation of the intestines results in bloody diarrhea hemorrhagic uremic syndrome (HUS)
• Source :– Undercooked hamburger , salami– Unpasteurized milk, Well water– Fruits and Vegetables
Apr 10, 20237
Shigella It causes diarrhea in human which called bacillary
dysentery,, Shigellosis is a cause of traveler’s diarrhea from food and water contaminated in developing countries.
Source : Salads and sandwiches Raw vegetables
Apr 10, 20238
Listeria
It is widespread in nature, in soil and water . It grows at low temperature and in refrigerator. It is very dangerous pathogens for pregnant
women; it can transmit from mother to baby through placenta results in abortion.
Source Ice-cream ,unpasteurized milk,
soft cheeses
Ready-to-Eat foods, salads Apr 10, 20239
Vibrio
this bacteria found in warm coastal areas and in the summer months when water gets wormer
V. parahaemolyticus typically causes non-bloody diarrhea V. cholerae cause watery diarrhea (called "rice water stools" It cause electrolyte imbalance by Losing body fluids Severe cases, 12 - 20 liters of liquid lost in a day Untreated cases - Mortality Rate about 50% By treatment with electrolytes mortality 1%Source : Raw or undercooked fish and shellfish Drinking contaminated water Eating food washed or made with contaminated water Apr 10, 202310
Clostridium perfringens
One of the most common spore forming bacteria causing food poisoning.
Cooking kills Bacterial cells, but the spores grow into new cells.
When food prepared in large quantities and kept long time before serving it cause infection
Outbreaks usually linked to institutions (hospitals, school cafeterias, and prisons).
Sources such as Beef and Poultry
Apr 10, 202311
Clostridium botulinum
This is one toxin producing bacteria producing neurotoxin
Leads to flaccid paralysis. (Botulism) is rare but fatal caused by eating
food contamination as it end by death .
Sources: Honey, home-canned vegetables and fruits, and
salted fish .
Apr 10, 202312
Bacillus cereus
It is type of bacteria that produces toxins. These toxins can cause two types of illness:
diarrheal toxin, emetic toxin, It presents in food and can multiply quickly at
room temperature
Source : Rice , sauces, soups Food that have stayed too long at room
temperature Apr 10, 202313
Symptoms of food poisoning
General symptomsFever, chills, malaise , aches, swollen lymph nodes• Salmonella typhi,• Listeria monocytogenes,• Campylobacter. Jejuni
Upper GIT signsNausea, vomiting, abdominal pain, diarrhea &• S. aureus and its toxins• B. cereus and its toxin
Apr 10, 202315
Lower GIT signsLower abdominal cramps & diarrhea :• Clostridium perfringens,• Bacillus cereus• Salmonella, Shigella,
Neurological signsVisual disturbances, vertigo
& paralysis
Clostridium botulinumApr 10, 202316
The main cause for food poisoning is eating food contaminated by Bactria
The bacteria need suitable condition to multiply as temperature, moisture, oxygen and have some protein,
In suitable condition
One bacteria multiply to more than four million bacteria in eight hours, and make food unsafe to eat within few hours.
controlling bacteria
Controlling bacteria, make food safe . and Prevent food poisoning begin from kitchen
by:
controlling bacteria Cooking at proper temperature destroys harmful
bacteria that may be present in food
Chilling By following Cooling , Freezing rules control bacterial growth can be controled
Cleaning surface , products , wash hands and
good hygiene.
Separation to prevent cross-contamination via hands, utensils, surfaces
Temperatures control Most types of pathogenic
bacteria can grow in temperature from 41ºF to 140ºF (5ºC to 60ºC) which called temperatures danger zone (TDZ),
To prevent bacteria from growing, we must set the refrigerator temperature not higher than 39ºF (4ºC).
Refrigerator must not be too full, as Cold air must circulate to keep food safe.
cooking Heating the food for enough time and at high
temperature, kill harmful microorganisms Always stir while heating and rotate food to
distribute heat. Avoid :
Interrupted cooking. Never refrigerate partially cooked products to be later cooking in the oven.
Traditional recipes for limited cooking: as eating Raw oysters, raw ground beef, and soft boiled eggs.
Microwave cooking
Microwaved food may have cold spots which are ideal for bacterial growth.
When use it for reheating food it must be leftovers to minimum of 165ºF (74ºC) and serve immediately.
Freezer temperatures it Slow bacterial growth but do not necessarily kill
bacteria. If food has been temperature-abused before
freezing it will be unsafe upon thawing Food must be stored properly to be safe.
The Thawing law Never defrost food at room temperature. Thawing food in the refrigerator. For a quick thawing, thawing in the microwave if
cooking immediately.
leftoversRemember Refrigerate food within 2 hours. Keep leftovers in small containers for quick
cooling. Use a cooler or ice pack to keep perishable
food cold, especially on hot summer days. When in doubt, throw it out!
Keep Clean
Wash hands, utensils, and surfaces, in hot, soapy water before and after food preparation
For protection against bacteria use disinfectants cleaners or a mixture of bleach and water on surfaces.
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Keep Clean
All cutting boards Cutting boards (including plastic, acrylic, and
wooden boards) Should be run through the dishwasher or
washed in hot, soapy water after each use
Produce: Wash raw produce under running water. Use vegetable brush to remove surface
dirt. Cut away any damaged or bruised areas .
Keep Clean
Wipe up spills in the refrigerator,
microwave immediately.
Towel If using cloth towels, wash them in the
boiling water Using paper towels to clean up kitchen
surfaces. Then , throw it away
separation
Separation to prevent cross contamination: Safely Separate
Separate raw meat and seafood
from other food in refrigerator
to avoid cross-contamination
Clean up Wash hands, cutting boards, dishes
after contact with raw meat,
or unwashed products.
Take two separate
USE one cutting board , Knife etc ,for raw meat, and another one for salads and ready-to-eat foods.
Never place cooked food on the same plate or cutting board which previously held raw food.
Handling dairy products , raw meat, then prepare salads, sandwiches can create “Cross-contamination”.
Restaurants staff personal hygiene
Clean hands and clothing. Minimize jewellery on hands. Tie-back or cover hair. Wearing gloves. Clean and short fingernails. Sick personal not prepare
food Avoid :
touching face and hair. cough or sneeze over food. taste food with your fingers.
They must have Basic food safety education and correct personal hygiene:
Pest Control Food must Stored in tightly closed containers to
keep out pests.
Flies: Windows and doors must properly closed. Use fly proof mesh if possible.
After applying pesticide spray, always maintain a time gap before reusing kitchen to prepare food , also wash utensils before reuse
Ants: Always keep kitchen countertops clean
Rodents: Use food traps. If using rat poisons, don’t keep it for extended period.
Hazard Analysis and Critical Control Point
(HACCP)
The HACCP It is the system that is required for any food
business or organisation in most countries.
The joint FAO / WHO Codex Alimentarius Commission recommends the HACCP approach to enhance Food Safety in all process of food production.
The HACCP Advantages
Gives insight in the critical control points of the product process
Gives trust for the consumer that products are produced safely and hygienically
Reduces the costs of food borne illness.
The HACCP disadvantages:
Need to train supervisors, managerial and
production staff
Reduced Staff time available for other tasks
Increased production , implementation and supervisory costs
Reduced flexibility in production process and introduction of new products.
Food pathogens enter food chain at multiple points.
Fight bacteria by cook , clean , chill and separate.
Maintain a clean and sanitary environment for all areas of food production.
Apply good personal hygiene.
Prevent cross contamination in the kitchen.
All organization dealing with food production must enforced by governments to applying HACCP system
Remember to make food safe