Download Why High Incidence of Foodborne Disease?

Foodborne pathogens
Gabriella Kiskó, PhD
Corvinus University of Budapest,
Department of Microbiology and Biotechnology
ERASMUS IP Maribor, 2011
 Food safety issues such as E. coli O157, Listeria are never
far from the newspaper headlines, becoming grounds for
increasing public concern
ERASMUS IP Maribor, 2011
Foodborne illness
 term used to describe the
adverse health effects
associated with the
consumption of
 biological,
(including parasites)
 chemical and
 physical
hazards in food.
 More than 200 diseases are
spread through food
ERASMUS IP Maribor, 2011
Foodborne hazards
 Microbiological
 Parasitic
 Bacterial
 Viral
 Prion
 Genes (resistant)
 Chemical
 Drug residues
Antibiotics, Pesticides, Disinfectants
 Environmental contaminants (dioxins, PCBs, heavy
metals, radioactive isotopes,
 Physical
 Foreign bodies (needles, fragments of glass, pieces of
plastic or metal, etc.)
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Food borne hazards
 microbiological
 chemical

physical
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Don’t count on these to
test for food safety!
Sight
Smell
Taste
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Estimated Annual Incidence of Foodborne
Illness with Other Illnesses in U.S.
Illness
Bronchitis
Flu
Common cold
Foodborne disease
No. of Cases
12 million
50 million
62 million
76 million
CDC estimates (2000)
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The infections we see are only the
tip of the iceberg…..or the eyes of
the hippo!
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Foodborne Diseases Pyramid
Reported to health department
Culture-confirmed case
Lab tests for organism
Specimen obtained
Person seeks care
Person becomes ill
Population exposures
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Why does it take so long?
ERASMUS IP Maribor, 2011
Food borne outbreaks
250
200
150
Unknown
Suspected
Confirmed
100
50
0
1999
2000
2001
2002
2003
2004
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Are you at Risk?
YES, you are!
Foodborne disease each year
 Total 76 million cases (estimated), 325,000 hospitalizations, and 5000 deaths from
acute foodborne infections (Mead et al, 1999) ↔
illnesses, 60,000 hospitalizations, 1,800 deaths




Known pathogens 14 million
Most cases without defined agent
1 in four Americans gets a foodborne illness each year
1 in 1000 Americans is hospitalized each year
At least $56.5 billion annually in medical and associated costs due to foodborne illness
 1400 foodborne outbreaks reported annually
 In 2005 1.8 million people died from diarrhoeal diseases.
 A great proportion of these cases can be attributed to contamination of food and
drinking water
 3.5 million cases, 33,000 hospitalizations and 1,600 deaths are caused by 5
pathogens
 Salmonella, E. coli O157:H7 and other STEC, Campylobacter, Listeria monocytogenes,
Toxoplasmosa
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Additional impact of foodborne
illness - Cost
U.S. - $6.9 billion/yr.
South Korea - $16-$28 million/yr.
Australia - $1.7 billion in 1999
Economic losses from foodborne
diseases estimated annualy
$ billion
Pathogen
Emerging foodborne diseaeses estimated annually
Cases
No. of
No. of
Illnesses
Deaths
Campylobacter spp.
1,963,141
10,539
99
1.2
Salmonella non-typhoidal
1,341,873
15,608
553
2.4
E. coli O157:H7
62,458
1,843
52
0.7
E. coli non-O157-STEC
31,229
921
26
0.3
L. monocytogenes
2,493
2,298
499
2.3
Total
3,401,194
31,209
1,229
6.9
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Cost of Foodborne Illness in the Food
Service Industry
ERASMUS IP Maribor, 2011
Categories of foodborne illnesses
 Food infection
 Result from the growth of microorganisms in the body,
which are carried by food or water into the host
 e.g. Salmonella sp., Campylobacter sp., Listeria monocytogenes , Yersinia enterocolitica, Hepatitis A, norovirus,
rotavirus, Trichinella spiralis, Giaria duodenalis,
Toxoplasma gondii, Cryptosporidium parvum
 Food intoxication (poisoning)
 Results from the action of microbial toxins, that contaminat food, toxins are
ingested
 e.g. Staphylococcus aureus, Clostridium perfigens, Clostridium botulinum
 Infection-mediated intoxication (toxicoinfection)
 Results from the consumption of food containing harmful bacteria, which in
the intestinal tract produce toxins that cause illness
 e.g. Shigella spp., Shiga toxin-producing Escherichia coli
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Foodborne infections vs intoxication
Infections
 Bacterial / Viral / parasite
 Invade and or multiply in lining of
intestine
 Incubation period - longer, hours to
days
Intoxications
 toxins ( natural / preformed bacterial /
chemical)
 No invasion or multiplication
 Incubation period – shorter, minutes to
hours
 Symptoms – vomitting , nausea,
diarrhea , diplopia, weakness, resp.
failure , numbness, sensory/motor
dysfunction
 Not spreads from person to person
 Spreads from person to person
 Factors-inadequate cooking , improper
 Factors-inadequate cooking, cross
handling temperatures
contamination , poor personal hygiene,
bare hand contact
 Symptoms – diarrhoea , nausea,
vomitting , abdominal cramps, fever
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Is the food safe for everyone at the table?
Some people have
a greater risk for
foodborne illnesses.
A food you safely eat might
make others sick.
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Highly Susceptible Populations
Young
e.g. Salmonella, Shigella, E. coli O157:H7
Old
e.g. Salmonella, Shigella, E. coli O157:H7
Pregnant
e.g. Listeria, Toxoplasma, Hepatits E
Immuno-compromised
e.g. Salmonella, Listeria
ERASMUS IP Maribor, 2011
Major Identified Foodborne
Pathogens, United States – circa 1920
 Bacterial
 Brucella
 Clostridium botulinum
 Salmonella typhi
 Salmonella non-typhoidal
 Streptococcus
 Parasitic
 Trichinella spiralis
 Taenia saginata
 Taenia solinum
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Major identified foodborne pathogens,
United States – circa 2002
Bacterial:
 Bacillus cereus
 Brucella
 Campylobacter*
 Clostridium botulinum
 Clostridium perfringens
 E. coli O157:H7*
 E. coli, non-O157 STEC*
 E. coli, other diarrheagenic*
 Listeria monocytogenes*
 Salmonella Typhi
 Salmonella non-typhoidal
 Shigella
 Staphylococcus
 Streptococcus
 Vibrio cholerae, toxigenic*
 Bacterial (continued)
 Vibrio vulnificus*
 Vibrio, other*
 Yersinia enterocolitica*
 Parasitic
 Cryptosporidium*
 Cyclospora*
 Giardia*
 Taenia
 Toxoplasma*
 Trichinella
 Prions
 Viral
 Norwalk-like viruses*
 Rotavirus*
 Astrovirus*
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 Hepatitis A
* Recognized as foodborne in last 30 years
Maribor, 2011
Estimated Number of Cases of Foodborne Illness Annually in US
Cases from Foodborne Transmission
Norwalk-like viruses
Campylobacter spp.
Salmonella (nontyphoid)
Clostridium perfringens
Giardia lamblia
Staphylococcus food poisoning
Toxoplasma gondii
Shigella spp.
Yersinia enterocolitica
Escherichia coli O157:H7
Enterotoxigenic E. coli
Streptococcus
Astrovirus
Rotavirus
Shiga-toxin producing E. coli (nonO157)
Bacillus cereus
E. coli (other diarrheic)
Cyclospora cayetanensis
Vibrio parahaemolyticus
Hepatitis A
Listeria monocytogenes
Brucella sp.
Botulism
Trichinella spiralis
Vibrio cholerae
Vibrio vulnificus
9, 200,000
1,963,000
1,332,000
248,500
200,000
185,000
112,500
90,000
86,800
62,500
55,600
51,000
39,000
39,000
31,000
27,400
23,900
14,600
5,000
4,200
2,500
780
60
50
50
50
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IP Maribor,
2011
P. S. Mead et al. Emerging
Infect. Dis.
5:607 (1999)
Trends and Sources of Zoonoses, Zoonotic Agents,
Antimicrobial Resistance and Foodborne Outbreaks in the
European Union in 2006
Incidence =
case/100˙000
inhabitant/year
Source: The Community Summary Report on Trends and Sources of Zoonoses, Zoonotic Agents, Antimicrobial
Resistance and Foodborne Outbreaks in the European Union in 2006, The EFSA Journal (2007) 130
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Foodborne outbreaks in 2008 - EU
Causes of illness in outbreaks,
2003–2008 - USA
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Main Reasons for Foodborne deseases









Food prepared too far in advance and stored at room temperature.
Inproper cooling
Cross-contamination.
Storing hot food below 63ºC
Inadequate reheating
Undercooking
Low level of hygiene
Infected food handlers
Use of leftovers
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Hours
Minutes
bacteria/ml
Number of
0
00
1
0
0
0
0
0
1
1
1
1
1
1
2
2
2
2
2
2
3
3
3
10
20
30
40
50
00
10
20
30
40
50
00
10
20
30
40
50
00
10
20
2
4
8
16
32
64
128
256
512
1024
2048
4096
8192
16834
32768
65536
131072
262174
524288
1048578
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Transmission of foodborne pathogens
SOME GENERAL PATHWAYS OF CONTAMINATION
UNWASHED HANDS
CROSS-CONTAMINATION.
FOOD HANDLERS
POOR HYGIENE
FOOD CONTACT SURFACES
WATER, IRRIGATION WATER
VERMIN
PACKAGING
SOIL
INGREDIENTS
AIR
SLAUGHTER
STORAGE AT INCORRECT
TEMPERATURE
INSUFFICIENT COOKING
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Fecal–oral routes of transmission of foodborne intestinal pathogens
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Foodborne Enteric Microbial Contamination Transmission:
Fecal contamination prior to harvest or collection
 Animal foods contaminated naturally by infection (e.g., salmonella)
 Surface contamination (e.g., feces on fur, feathers, hooves, etc.)
 Shellfish and other fish contaminated in their environment
 Fecal (sewage) contamination of water → pathogen uptake by
filter-feeding on waterborne particles
 Fish and shellfish naturally colonized by aquatic pathogens
 Vibrio cholerae in copepods, fish and shellfish
 Produce contaminated by irrigation with sewage or contaminated
water or fertilization with nightsoil (feces) or animal feces.
 Soil contaminating plants and animals with bacteria, fungi, etc.
ERASMUS IP Maribor, 2011
Foodborne Enteric Microbial Contamination Transmission:
Foods Implicated in Foodborne Illness: Meats
 Red Meats
 High contamination in comminuted and processed meats (e.g., ground
beef, sausage)
– High surface area, increased contact with processing equipment;
increased handling; variety of sources from the animal (organs,
trimmings, etc.).
 Ex., E. coli O157:H7 outbreaks due to undercooked hamburger
 Poultry
 High contamination levels in cut-up poultry
Increased handling, processing and contact with common equipment
Salmonella and campylobacters are prevalent in some poultry flocks
– can contaminate an entire processing plant via equipment and
process baths (e.g., chiller tank)
 Eggs
Endogenous contamination by Salmonella enteritidis in some flocks
– Time and temperature abuse leads to proliferation in the egg
 Raw/undercooked eggs a source of exposure and infection
ERASMUS IP Maribor, 2011
Foodborne Enteric Microbial Contamination Transmission:
Foods Implicated in Foodborne Illness: Fish
 Contamination depends on type of seafood,quality of harvest water and
amount of processing, handling and storage.
 Bivalve mollusks (oysters, clams, mussels, etc.); filter feeders
 Accumulate enteric pathogens from fecally contaminated waters
 Acquire high levels of vibrios from their environmental waters
 Crustaceans (e.g., crabs)
 Acquire some pathogens by feeding on mollusks
 Acquire high levels of vibrios from their water environment
Vibrio levels can increase during handling, processing and storage,
especially if temperatures are too high.
 Fin fish
 Outer surface and epithelial lining (e.g., gut) contamination by enteric
microbes in fecally contaminated waters;
 Contamination during processing (e.g., filleting).
 Endogenous contamination:
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Ex:: Diphyllobothrium latum; fish tapeworm; anemia; undercooking
Maribor, 2011
Foodborne Enteric Microbial Contamination Transmission:
Other Foods Implicated in Foodborne Illness
 Produce (fruits and vegetables)
 fecal contamination in irrigation water and other fecal sources (animal
droppings, birds, etc.)
 inadequate or unsanitary picking, washing or processing.
 Dairy Products
 In developed countries milk and related dairy products are usually
made from pasteurized milk.
Raw milk and products (e.g., cheeses) made from unpasteurized milk are
high risk of bacteria contamination
– salmonella, campylobacter, brucella, yersinia, listeria,).
 Unpasteurized fruit juices and other beverages
 fecal contamination from animal and human sources
 Deli, "Fast" and Restaurant Foods
 salads, sandwiches, other fast, deli or restaurant foods
 become fecally contaminated during preparation and handling
 Cereal and Grain: inadequate storage of cooked rice/grain
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Maribor, 2011
Some virulence factors of pathogens
The ability to:
 1. Adherence (examples)
 eg. fimbriae - Escherichia coli
 2. Avoid phagocytosis
 eg. capsules - prevent phagocytosis
and help with attachment (adherence) eg. Streptococcus pneumoniae
 3. Penetrate
 get into host and spread eg. coagulase Staphylococcus aureus - coagulate
blood
 4. Produce Enzymes
 spread, prevent host defenses and cause damage at or near site of infection –
eg. collagense Clostridium perfringens
 5. Produce Toxins
 cause damage at distant site
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Toxins
Provide properties to spread and cause damage to the host.
 Endotoxins from inside the cell. Released upon cell lysis.
 Exotoxins are secreted out of the cell during cell life.
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Exotoxin
Exotoxin
Source
Metabolic product
Chemistry
Fever?
Neutralized by antitoxin
LD50
Mostly Gram +
By-products of growing cell
Protein
Water soluble
No
Yes
Small - Very potent
1 mg of Clostridium botulinum toxin can kill
1 million guinea pigs
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Exotoxins - three types
 1. Cytotoxins
 kill cells
 Streptococcus pyogenes toxin
 2. Neurotoxins
 interfere with normal nerve impulses
 Clostridium botulinum – botulin toxin
 prevents impulse from nerve cell to muscle cell
 results in muscle paralysis
 3. Enterotoxins
 effect cells lining the G.I. Tract
 Vibrio cholerae cholera toxin
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Exotoxins
Exotoxin
• Corynebacterium diphtheriae
• Streptococcus pyogenes
• Clostridium botulinum
• C. tetani
• Vibrio cholerae
• Staphylococcus aureus
Inhibits protein synthesis
Membrane-disrupting
Neurotoxin - paralysis
Botox
Neurotoxin - paralysis
Enterotoxin - cause severe
diarrhea
Enterotoxin
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Endotoxin
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Endotoxins
Source
Gram–
Metabolic product
Present in LPS of outer membrane
Chemistry
Lipid
Fever?
Yes
Neutralized by antitoxin
No
LD50
Relatively large
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Type of bacterial pathogens
 Obligate pathogens: organisms that will always cause
infection and disease whenever and wherever they are
encountered
e.g. Yersinia pestis – plague, Bacillus anthracis - antrax,
Salmonella Typhimurium - salmonellosis
 Opportunistic pathogens: organisms that can only cause
disease in an immuno-suppressed person or under
unusual circumstances e.g. skin infections
e.g. Staphylococcus aureus, Listeria monocytogenes
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Gram-negative pathogenic bacteria
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Campylobacter jejuni
 Characteristics: no growth at <30 °C,
microaerophilic, grow with 10% CO2 / 5% O2 .
sensitive to drying, heat, acidic conditions, and
disinfectants
 Infection, campylobacteriosis
 The most commonly identified bacterial cause
of diarrheal illness in the world
 Infective dose: 500 -10,000 bacteria /ml
 Incubation: 2-5 days
 Symptoms: watery diarrhea, vomiting,
headache, fever, muscle pain, Guillian-Barre
Syndrome, death (rare)
 Children are at an increased risk of infection
 Foods: poultry, dairy products, water
 Reservoir: wild/ domestic animals, most
commonly cattle and poultry
 Transmisson: intestinal tracts of wild/ domestic
animals, fecal contamination of skin during grow
out and processing, fecal-oral, person-to-person
 Prevention: Proper pasteuriation and cooking
can prevent the infection
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Campylobacteriosis cases
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Some Important Campylobacter Outbreaks in the World
Year
Country
Food
No. of cases
2000
U.K & Wales
Raw milk
333
2001-2002
Australia
Chicken
601
2005
Denmark
Chicken salad
4
2005
Scotland
Chicken pate
82
2005-2006
U.S.A
Water
32
2007
U.S.A
Cheese (from unpasteurized
milk)
67
2007
Denmark
Water
16
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Salmonella Enteriditis
 Named named after Daniel Elmer Salmon, an
American veterinary scientist
 Characteristics: enteric bacterium; all strains
are pathogenic;
 Colonization of intestinal epithelium
 Infection
 Symptoms:
Two diseases type:
– Enterocolitis - salmonellosis (most commonly by
S. enterica serovar Typhimurium): disease onset
within 8 - 48 hrs; headaches, chills, vomiting, diarrhea and fever (23 days); death (rare) - YOPI
continuous shading of organism for months/years; treatment - none
– Typhoid fever (Salmonella enterica serovar Typhi ):
Septicemia leading to high fever that can last for several weeks;
mortality is 15% if untreated; treatment - antibioticsERASMUS IP Maribor, 2011
Salmonella Enteriditis
 Infective dose: 100 – 1.000.000 bacteria/ml
 Reservoir: domestic and wild animals, it
colonize ovarian tissue of poultry,
 Foods: poultry, meat, eggs and egg products,
sliced melons, vegetables, chocolate
 Transmission: water, soil, insects, animals,
and humans, internal contents of eggs, contact
with infected animals, or by fecal-oral person to
person contact
 Temporary carrier state can continue for
months, especially in infants.
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Salmonella Enteriditis
 Children, elderly, immunocomcpormised - increased risk of
infection
 Amphibians and reptiles are colonized
Turtles, salamanders, and lizards ~74,000 Salmonella infections
annually in the US
 Prevention: proper cooking (70 °C for 10 min),
improved sanitation, adequate personal hygiene,
monitor for carrier state among food handlers and exclusion of
infected individuals as food-handlers and health care providers,
restriction of sale of pet turtles and reptiles,
proper sewage treatment
No under age of 5
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Some Important Salmonella Outbreaks in the World
Year
Country
Food
Serotype/Phage
type
No. of
cases
No. of
deaths
1991
Germany
Orange cream
S. Enteritidis PT4
109
4
1991
Germany
Puding (egg)
S. Enteritidis
87
10
1994
U.S.A
Ice cream
S. Enteritidis
224000
-
2003
U.S.A
Chicken
S. Typhimurium
38
-
2005
Spain
Processed
chicken
S. Hadar
2138
1
2006
Norway
Salami
S. Kedougou
54
1
2008
Ireland&U.K
Beef, chicken
S. Agona
119
-
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Escherichia coli O157:H7
 Characteristics: produce Shiga-like toxins
(verotoxin), - colonize small intestine ,
verotoxin production
 Infection based intoxication
 Incubation: 2-8 days
 Infective dose: 10 -100 bacteria/ml
 Symptoms: dehydration, bloody diarrhea,
nausea, vomiting, kidney failure – HUS,
death (<5% - 50%)
 Primary cause of HUS in children in the US
 Reservoir: cattle and deer
(humans - reservoir for person-to-person
transmission)
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Hemolytic Uremic Syndrome
(HUS)




HUS - destruction of red blood vessels, impairment of renal
function
Most HUS in the United States results from E. coli O157:H7
infections
 Children and the elderly are at the greatest risk for
progressing to HUS
Usually need for dialysis and other invasive treatments
Long-term complications in 15% of HUS cases
 Renal impairment, hypertension, stroke
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Transmission of E.coli O157
Transmission:
• fecal-oral route,
• direct or indirect contact
with cattle;
• manure contaminate food,
• contaminated water,
• polluted irrigation water,
• swimming in, inadequately
chlorinated pools and
outdoor water sources
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E. coli O157:H7 transmission model – 2003
Sheep,
Caribou,
other
ungulates?
Cow
Meat
Cow
Contact
Milk
Water
Human
Human
Water
Manure
Deer
Fruits and
vegetables
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Escherichia coli O157:H7
 Foods: ground beef, yogurt, and lettuce,
contaminated fruits and vegetables,
unpasteurized milk and juice
 Prevention: Hygiene and proper cooking,
improved sanitation,
adequate personal hygiene and avoiding
consumption of undercooked ground
beef and unpasteurized dairy and
fruit juice products,
proper food handling techniques,
consumption of potable water,
avoiding farm animal contact
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E. coli O157
 Visiting
 Farms
 „Zoo”
 Camps
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Some important E. coli O157:H7 Outbreaks in the World
Country
Year
No of cases(age)
Complications
Infection
source
Japan
1996
>10000 (students)
12 deaths
Alfalfa
U.S.A
1999
321
-
Beef
Canada
2000
27
5 deaths
Water
Sweden
2002
39
-
Fermented
sausage
U.S.A
2002
34
5 HUS
Ground beef
Netherlands
2005
32
-
Steak tartare
U.S.A
2006
376
3 deaths
Fresh spinach
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Shigella dysenteria
 Genus is named after Kiyoshi Shiga,
 Shigellosis or bacillary dysentery
 Incubation: 1 to 7 days
 Infective dose: 10-100 bacteria/ml
 Symptoms: diarrhea, abdominal pain, fever, blood in feces
(ulcers on the intestinal wall) bloody , nausea, dehydration,
prostration and vomiting
shiga toxin (verotoxin) - cytotoxin, causes severe diarrhea,
massive tissue inflammation and destruction (blood and pus),
HUS, death (rare, but high in developing countries)
 Foods: salads and seafood
 Reservoir: infected humans and higher primates
 Transmission: 4F, y ingestion of contaminated food or water or
by fecal-oral person-to-person contact. Secondary household
cases are common
 Children are at an increased risk of infection
 Prevention: improved hygiene and waste-handling practice
and personal hygiene
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Yersinia enterocolitica









Characteristics: capable of growth at 2 °C
Infection
Incubation: 4-7 days
Infective dose: 108-109 bacteria/ml
Symptoms: severe abdominal pain, diarrhea, fever,
vomiting, arthritis in adults, pseudoappendicitis,
death (rare),
sporadic
Reservoir: major reservoir pigs, others: rodents,
rabbits, horses, sheep, cattle , dogs , cat
Foods: Contaminated raw pork or beef, drinking
water, milk products, tofu
Yersiniasis is more common in Northern Europe,
Scandinavia, and Japan
Prevention: Avoid to contamination of porcine
wastes and fecal contamination
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Gram-positive pathogenic bacteria
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Staphylococcus aureus
 Characteristics: coccoid, fakultative anaerob
meaning the "golden grape-cluster berry
high NaCl tolerance (7-10 %, some strains at 20 %)
aw min 0,83-0,99
! enterotoxin production min - 0,86 aw
↓
capable of growth at low aw
Heat stable enterotoxin,
heat may kill bacateria but not eliminate toxin
D100=1-3 hours, D120=10-40 minutes
Toxin production, if S. aureus > 104/g
 Coagulase-positiv strains are important
ERASMUS IP Maribor, 2011
Staphylococcus aureus
 Range of illnesses: eg. from impetigo, furuncles, scalded
skinsyndrom, to eg. pneumonia, meningitis, endocarditis,
sepsis
 Bacterial intoxication
 Symptoms: vomiting, diarrhea, prostration, abdominal cramps,
death (rare)
 Incubation: 3- 8 hours
 Infective dose: 105-106 bacteria/ml
 Reservoir: human, animals
 Food: Meat and meat products, milk and dairy products, custard
or cream-filled pastries, egg foods, cheese, prawns and salads
containing potato, pasta
 Source: skin, hair, nose, persons with skin injuries or surgical
wounds or with piercings and fresh tattoos, pus, soil, dust, air
 Transmission: foods by infected food-handlers
 Prevention: proper cooking and chilling, adequate personal
hygiene, keep ingradients under 7 °C to avoid toxin production,
exclusion of skin infected individuals as food-handlers
ERASMUS IP Maribor, 2011
Listeria monocytogenes
 Characteristic: named for Joseph Liser, capable of growth at refrigeration
temperatures (! 0,5 °C-45 °C), salt tolerant (at pH 6 16 % NaCl)
 Incubation: 3-70 days
 Infective dose: 103?, YOPI
 Symptoms: 3 type of deseases:
♦ Adult listeriosis: fever, muscle/head aches, nausea or diarrhea,meningitis,
encephalitis, meningoencephalitis, bacteremia, if nervous system is infected, stiff
neck, confusion, loss of balance, or convulsions, death
♦ Listeriosis in pregnancy/neonatan listeriosis: acquired transplacentally or during
or after delivery, listeriosis of a newborn, neonatal sepsis/meningitis, mothers flulike, stillbirths, spontaneous abortion, death
♦ Listeria gastroenteritis - Febrile gastroenteritis : in normal hosts, fever, diarrhea,
vomitting, self-limited, ingestion high numbers of organisms, no death
 High mortality (10-30 %, or even higher in risk groups)
 Carrier state: among healthy adults 1%-21%
ERASMUS IP Maribor, 2011
Listeria monocytogenes





Foods: unpasteurized milk and fruit juices, soft
cheese, raw meat, ice cream, ready-to-eat,
lunchmeats, vegetables
Sources: soil, water, damp environments,
domestic/ wild animals (esp. poultry)
Reservoir: silage, infected animals (cattle,
poultry, sheep), humans; environmental - soil,
forage, water,mud
Transmission: by ingestion of contaminated
food
Prevention: wash uncooked vegetables
thoroughly, consume refrigerated, perishable
items as soon as possible or freeze
ERASMUS IP Maribor, 2011
Listeria monocytogenes
Prevention
Some special recommendations for
pregnant woman
 Do not eat hot dogs, deli meats, or luncheon meats unless
they are reheated until steaming hot
 Do not eat soft cheeses unless they have labels that clearly
state they are made from pasteurized milk
 Do not drink unpasteurized (raw) milk and do not eat foods
that contain unpasteurized milk
 Do not eat refrigerated pâtés or meat spreads.
 Do not eat refrigerated smoked seafood unless it is an
ingredient in a cooked dish, such as a casserole.ERASMUS IP Maribor, 2011
Listeriosis outbreaks
Death/cases/letality
Nova Scotia, Canada 1981
Massachusetts, 1983
17 / 41 / 41
14 / 32 / 43
Cole slaw mix
Pasterurized milk
Switzerland, 1983-1987
31 / 122 / 25
Cheese
Los Angeles, CA 1985
48 / 142 / 34
Jalisco soft cheese
Philadelphia, PA 1986-1987
United Kingdom, 1988-1989
16 / 36 / 44
94 / 355 / 26
Icecream
Paté
Illinois, 1994
USA, 1998-1999
North Carolina, 2000-2001
USA, 2000
USA, 2002
0 / 45 / 0
21
5
7
7
/
/
/
/
101
12 /
29 /
63 /
/ 21
42
24
11
Food
Chocolate milk
Hot dog
Mexican cheese
Ready-to-eat turkey
Sliced meat products
ERASMUS IP Maribor, 2011
ERASMUS IP Maribor, 2011
Bacillus cereus








Characteristic: spore-forming microorganism
Intoxication
Infective dose min. 105/g
Symptoms:
 Diarrheal desease: watery diarrhea, abdominal cramps and
pain; heat-sensitive enterotoxin produced during vegetative
growth in small intestine
 Emetic desease: nausea and vomiting; heat-stable
enterotoxin produced by growing cells in the food, death
(rare)
Incubation: 6 to 15 hours (diarrheal), 30 min. to 6 hours
(emetic)
Foods: diarrheal - meats, milk, vegetables, fish
emetic - rice products, starchy foods, casseroles,
puddings, soups
Source: soil, dust, cereal crops, spices
Prevention: holding food >60˚C or <10˚C
ERASMUS IP
Maribor, 2011
Clostridium botulinum
 Characteristic: obligate anaerobic, spores are highly heat –
resistant (survival at 100 °C for several hours, but 120 °C for
30 min. kill spores)
production of botulinum neurotoxin, toxin easily destroyed by
heat (cooking at 80 °C for 30 min)
 Named after botulus, latin: sausage, 7 serotype: A, B, C, D,
E, F, and G
pH: 4,6-9 - food pH < 4.5 → pasteurization
food pH > 4.5 → sterilization
 Target organism of industrial heat treatments
 Symptoms: Botulism occur in 3 forms: foodborne, wound
and infant botulism
♦ Foodborne: weariness, weakness, dizziness,
doublevision, difficulty swallowing and speaking, paralisis,
death; toxin produced in contaminated food is eaten
♦ Wound and infant: neurotoxin is produced in infected
tissue and in the GI tract, death may occure
 Incubation (foodborne): 12 – 72 hours
ERASMUS IP Maribor, 2011
Agent
LD50(μ/kg )
Source
0.001
Bacterium
Shiga toxin
0.002
Bacterium
Tetanus toxin
0.002
Bacterium
Diphtheria toxin
0.10
Bacterium
Maitotoxin
0.10
Alga
Ciguatoxin
0.40
Fish
C. perfringens toxinok
0.1-5.0
Bacterium
Batrachotoxin
2.0
Frog
Ricin
3.0
Castor oil bean
Taipoxin
5.0
Snake venom
Tetrodotoxin
8.0
Fish
Tityustoxin
9.0
Scorpio
Sarin (GB)
100.0
Chemical agent
T – 2 toxin
1,210.0
Mycotoxin *
Botulinum toxin
ERASMUS IP Maribor, 2011
Clostridium botulinum
 Food: home-made cannes, home-made meat
products (black pudding, sausages), baked
potatoes, sous vide, garlic/ oil mixtures, lowacid canned foods, honey (infant botulism)
 Source: soil, water, soil contaminated foods
 Prevention: destruction of the spores through
processing or prevention of growth through
formulation, temperature control, or a
combination of these factors, proper heat
treatment, addition of nitrite prevents the
growth of Cl. botulinum
ERASMUS IP Maribor, 2011
Clostridium perfringens
 Characteristic: spore-forming, obligate anaerob
 Toxicoinfection: caused by sporulation of
bacterial cell in the intestine
 Incubation: 10- 12 hours
 Infective dose: dose >106/g
 Symptoms: abdominal pain, nausea, diarrhea,
fever, headache, vomiting usually absent, death
(rare)
 Foods: stews, gravies, beans, meat, poultry, fish
 Sources: meat and poultry, soil, animal and
human intestinal tracts
 Prevention: adequate reheating (toxin
inactivated at 100 °C for 1 hour)
ERASMUS IP Maribor, 2011
How are foodborne illnesses
prevented?





1. COOK.
2. SEPARATE.
3. CHILL.
4. CLEAN.
5. REPORT.
ERASMUS IP Maribor, 2011
COOK
•
•
•
•
•
Thoroughly cook meat (63 –74ºC), poultry (74ºC), and
eggs (63ºC).
Use a thermometer to measure internal temperature of
meat.
Cooked food should be reheated to 74ºC.
Hot foods should be kept hot at 57ºC or above.
Cook food immediately after defrosting.
ERASMUS IP Maribor, 2011
CLEAN
•
•
•
•
•
•
Wash produce under running water.
Remove and discard outer leaves from lettuce or
cabbage.
Wash hands before preparing food, between types of
food, and after preparation.
The single most important method of preventing
infectious diseases is to wash your hands.
Regularly clean and disinfect the refrigerator and freezer.
Clean and disinfect countertops regularly.
ERASMUS IP Maribor, 2011
When should you wash your hands?
 Before
 Preparing or eating food
 Treating a cut or wound
 Tending to someone who is sick
 After
 Using the bathroom
 Changing a diaper or helping a child in the
bathroom
 Handling raw meats, poultry or eggs
 Touching pets
 Sneezing or blowing your nose
 Tending to someone who is sick or injured
ERASMUS IP Maribor, 2011
SEPARATE
•
•
•
•
Do not cross-contaminate
Wash hands, utensils, and cutting boards after they
have been in contact with raw meat or poultry and
before they touch another food.
Put cooked meat on a clean platter.
Use different dishes and utensils for raw and cooked
foods.
75
ERASMUS IP Maribor, 2011
CHILL
•
•
•
•
•
•
Refrigerate leftovers promptly.
Set refrigerator temperature at 4ºC.
Set freezer temperature at -18ºC.
Separate large volumes of food so they will cool more
quickly.
Cold foods should be kept at a temperature of 5ºC or below.
Keep purchased food chilled until you get home from the
store.
ERASMUS IP Maribor, 2011
REPORT
Report suspected foodborne illnesses to your local health
department.
ERASMUS IP Maribor, 2011
Thank you for your attention!
ERASMUS IP Maribor, 2011