Enterotoxigenic, produces toxin E. coli (ETEC) Enteroinvasive, invades cells E. coli (EIEC) Enteroaggregative, forms clumps E. coli (EAEC) Enteropathogenic, causes inflammatory response E. coli (EPEC) Enterohemorrhagic, produces toxins E. coli (EHEC) Shiga toxin producing E. coli E. coli (STEC)

Foodborne pathogens Flashcards by Ghada .

E. coli Pathogens

Enterotoxigenic, produces toxin E. coli (ETEC)
Enteroinvasive, invades cells E. coli (EIEC)
Enteroaggregative, forms clumps E. coli (EAEC)
Enteropathogenic, causes inflammatory response E. coli (EPEC)
Enterohemorrhagic, produces toxins E. coli (EHEC)
Shiga toxin producing E. coli E. coli (STEC)

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An organism that has changed the U.S. food safety system 1992- hamburger fast food chain, new laws, HACCP
An emerging pathogen
Zero tolerance in raw ground beef

E. coli O157:H7

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Important Characteristics of E. coli O157:H7

Low infectious dose: 10 cells
Unusual acid tolerance
Resistance to environmental stress
Severe disease consequences: bloody diarrhea, HUS, TTP, death
Diseases affecting all age groups, more severe in young children

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HUS is

Hemolytic uremic syndrome, causes Kidney failure

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TTP is

Thrombotic thrombocytopenic purpura, causes blood clotting Fatality rate 90%

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Reservoirs of E. coli O157:H7

• Ruminants (cattle, sheep, deer) and other animals

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Undercooked ground beef
Fresh produce and sprouts
Unpasteurized fruit juices
Manure
Unpasteurized milk
Swimming water

Transmission vehicles of E. coli O157:H7

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Mode of Transmission of E. coli O157:H7

Ingestion of contaminated food • Contaminated water
Animal-to-person, Zoonotic Disease
Person-to-person

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Disease Symptoms of E. coli O157:H7

part 2#

-Non-bloody diarrhea, asymptomatic infection
-Hemorrhagic colitis (HC)
Bloody diarrhea, produces shiga toxin in intestine
- Death

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Treatment of E. coli O157:H7

Do not administer antibiotics!

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Some antibiotics increase Shiga toxin production, thus progress to HUS . ✅❌

✅

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Control Methods Outbreak of E. coli O157:H7

Improve hygiene at farm level
Pasteurize milk and juice
Meat irradiation
Proper cooking

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Poor countries, poor sanitation, infantile diarrhea, non-toxic

Enteropathogenic E. coli (EPEC)

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Invade mucous cells will have blood and mucous in stool

Enteroinvasive E. coli (EIEC)

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Produces toxin –does not invade mucous cells – common with

travelers to foreign countries

Enterotoxigenic E. coli (ETEC)

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Produces toxins, physical alteration of intestine

Enterohemorrhagic E. coli (EHEC)

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Forms clumps in intestinal tract, produces toxins

Enteroaggregative E. coli (EAggEC)

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is main symptom in newborns

Diarrhea

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What is the Invasive.

the bacteria invades the epithelial cells of the
colon via an Outer membrane protein that is plasmid
associated

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Symptoms are like dysentery caused by Shigella.
• Fever • Cramps
• Bloody diarrhea

Enteroinvasive E. coli (EIEC)

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Enterotoxigenic E. coli (ETEC)

Travelers diarrhea
Profuse watery diarrhea
Does not invade or destroy cells lining the intestine
can produce LT, ST or both

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Enterotoxigenic produce ST after is

colonizes the intestinal tract

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Labile Toxin (LT) is destroyed at

60°C for 30 min

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LT is similar to

cholera toxin

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Thrombotic thrombocytopenic purpura – Similar to HUS, occurs in

the elderly with brain damage

* Persistent diarrhea in infants * Long thin structures –adhesions- causes aggregative clumping * Produces shiga - like toxin

Enteroaggregative E. coli (EAggEC)

What is the Microbiology of Campylobacter?

* Thermophilic 42°C * Minimum growth temperature 30°C * Microaerophilic 85% N2, 10% CO2, 5% O2 * Slow growth • Fragile bacteria

Family Campylobacteraceae is a

Gram-negative

Responsible for one of the most frequently occurring forms of gastroenteritis in humans

Campylobacter

Campylobacter classified as

vibrio

causing spontaneous abortion in cattle and sheep

Campylobacter

Epidemiology of Campylobacter

Campylobacter jejuni and Campylobacter coli

Campylobacter Low infectious dose -

<500 cells

Reservoirs of Campylobacter

Poultry, cows, pigs, birds, rodents, sheep, horse, pets

Vehicles of Campylobacter

* Poultry (50-70% of outbreaks) | * Raw milk, untreated water, beef, pork pet contact

Campylobacteriosis

Watery diarrhea, fever, abdominal pain

Complications of Campylobacteriosis

arthritis, HUS, septicemia, meningitis and Guillain- | Barre Syndrome

Treatment of Campylobacteriosis

antibiotics of choice are: Ciprofloxacin and erythromycin

Campylobacteriosis have Growing resistance to antibiotics Especially to Ciprofloxacin. ✅❌

✅

Controls of Campylobacteriosis:

``` -Organism is very heat sensitive, so adequate cooking is all that is needed. • Use chlorinated water • Pasteurize milk • Cook chicken to proper temperature • Use food thermometer • Prevent cross-contamination ```

Warm blood animals are reservoirs of

Campylobacter jejuni

Poultry 80 % of broilers contaminated with………… turkeys and ducks also involved • Red meat 5% • Raw milk • Poultry and raw milk are the main sources

Campylobacter jejuni and Campylobacter coli

Risk factors: • Untreated water • Unpasteurized milk – leading cause of foodborne outbreaks (from feces of cows, 60% of cows are carriers) • Having a cat in the house – Organism directly transmitted to humans • Pet; cats and dogs account for 6% of human cases • Eating undercooked chicken – sporadic cases

Campylobacter jejuni and Campylobacter coli

Salmonella Occurs widely in natural environment found in

humans,reptiles, turtles, dogs, cats, animals, and eggs.

Salmonella Most common species implicated in foodborne outbreaks

S. Typhimurium, S. enteridtidis

Salmonella are mesophile, What's means?

it grows best in moderate temperature, neither too hot nor too cold.

Characteristics of Salmonella

``` Gram negative non-spore forming rod facultative Mesophilic Spread of infection is by zoonosis Can survive in sweeper dust for 10 months Is destroyed by cooking ```

Salmonella is ingested and goes to

intestine

Salmonella causes Membrane ruffling that allows it entry into the

mucosal cells

Salmonella remain and multiply in the

phagosome

Salmonella Symptoms

gastroenteritis

Factors that have influenced development of antibiotic – resistance

1. Overprescribing antibiotics 2. Over counter public access to Ab 3. Incomplete use of Ab 4. Storage of unused Ab for future use. 5. Parental pressure to treat children with Ab. 6. Prophylactic use of Ab in animals to promote growth

Staphylococcus aureus | • Greek term Staphy means a

a bunch of grapes, grain or berries

Competes with Salmonella as the most prevalent cause of food related illness

Staphylococcus aureus

Leading causes of Staphylococcus foodborne outbreaks

1. Inadequate refrigeration 2. Preparing foods far in advance 3. Infected person practicing poor personal hygiene 4. Inadequate cooking processing 5. Holding food in a warming devices that promote growth

time required to destroy 90% of the organisms) is | dependent on the composition of the food

D-value

Staphylococcus is

Mesophilic

Organism produces seven Staphylococcus enterotoxins (SE), that affect enteric

nervous system – intestines

conditions increase toxin production

Aerobic

conditions little toxin is produced (only need 1 | ug / 100 g of food)

Anaerobic

Foods commonly associated with Staphylococcal food poisoning fall into general categories

1. Meat, meat products (cured meats) 2. Mayo salads 3. Creamed filled bakery products 4. Dairy products

Symptoms Staphylococcal food poisoning

cramps, chills, diarrhea, sweating | Dehydration

Contamination of processed foods can be due to:

1. Humans 50% 2. Animals 3. Environmental sources

Foodborne pathogens Flashcards

(63 cards)