Global food safety
Dr. Mark Turner
Senior Lecturer in Food Microbiology
School of Agriculture and Food Sciences & Queensland Alliance for Agriculture and Food Innovation
University of Queensland, Brisbane, Australia
Email: [email protected]
Overview
Part 1
• Foodborne illness
• Control strategies
• Notable recent food poisoning outbreaks
• Outbreak investigation steps
Part 2
• New approaches to controlling foodborne pathogens
• Emerging issues in food safety
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Food security
• Definition – when all people, at all times, have physical, social and economic access to sufficient, safe
and nutritious food that meets their dietary needs and food preferences for an active and healthy life (WHO and FAO)
• Enough food is produced globally, but 1 billion people go hungry every day (FAO, 2012)
– 1. Availability
• relates to improving sustainable productivity in farming systems, including better natural resources management and conservation, and enabling policies to enhance productivity.
– 2. Access
• relates to enabling market access for smallholders, and to generating more income from cash crops, livestock products and other enterprises.
– 3. Utilisation
• relates to improving nutrition and food safety, increasing diversity in diets, reducing post-harvest loss and adding value to food.
Food Safety
• Definition: – assurance that food will not cause harm to the consumer when it is prepared
and /or eaten according to its intended use (Codex, 1997) CRICOS Provider No 00025B
Hanning et al 2012
Foodborne illness
• Foodborne disease is a major cause of illness and death globally – In developing countries
• leads to the death of many children
• can have long-term effects on children's growth as well as on their development
– In industrialised countries
• causes considerable illness
• heavily affecting healthcare systems
• In 2002 the World Health Organization (WHO) developed its ‘Global Strategy for Food Safety’ – “Effective control of foodborne disease must be based on evaluated
information about foodborne hazards and the incidence of foodborne disease” (surveillance)
– Determine the world-wide burden of foodborne diseases
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WHO 10 facts on food safety
1. More than 200 diseases are spread through food
2. Foodborne diseases are increasing worldwide
3. Food safety is a global concern
4. Emerging diseases are tied to food production
5. Minimize the risk of avian influenza (bird flu)
6. Preventing disease starts at the farm
7. Chemical hazards can contaminate food
8. Everyone plays a role in food safety
9. School is a place for food safety
10. Five keys to food safety
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http://www.who.int/features/factfiles/food_safety/en/index.html
Foodborne illness (estimates)
• World – 2.1 million deaths per year (WHO, 2000)
• US (pop. 300 million) – 9.4 million (55,000 hospitalisations, 1350 deaths) per year
• England/Wales (pop. 53 million) – 1.7 million (22,000 hospitalisations, 700 deaths) per year
• Australia (pop. 22 million) – 5.4 million (37, 000 hospitalisations, 125 deaths) per year
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‘Tip of the iceburg’
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• Reporting of illness
Seen by doctor – not reported
Notified – samples positive
Mild or asymptomatic
Serious symptoms - no medical attention
Forsythe 2000.
Foodborne illness in Australia
• In Australia, there are an estimated 5.4 million cases of food-borne illness every year, causing: – 18,000 hospitalisations
– 120 deaths
– 2.1 million lost days off work
– 1.2 million doctor consultations
– 300,000 prescriptions for antibiotics
• 20 million x 365 days x 3 meals = 21900 million meals
• 1 in 5000 chance (0.02% meals cause food poisoning)
• Once every 5 years
http://www.ozfoodnet.org.au/internet/ozfoodnet/publishing.nsf/Content/annual-
cost-foodborne-illness.htm http://www.science.org.au/nova/030/030key.htm
1. Foodborne illness
http://www.ozfoodnet.gov.au/internet/ozfoodnet/publishing.nsf/Co
ntent/annual-cost-foodborne-illness.htm
Food Safety
• Foodborne illness causes:
• 1. Biological* – bacteria, virus, protozoan, prion, fungi, parasite
• 2. Chemical – natural (e.g. allergens, algal toxins, acrylamide)
– contaminated (e.g. pesticide, colourants, melamine)
• 3. Physical – Metal, stones, glass
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The top foodborne pathogens
• Most (50-70%) foodborne gastroenteritis is due to unknown pathogens
• US (91%), UK (94%), Australia (90%)
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Sallam et al., 2011; Adak et al., 2005; Hall et al., 2005
0
10
20
30
40
50
60
70
%
USA
UK
Australia
Bias in results/estimates
• Notifiable organisms – Different for different countries
• Testing regime and methods – viruses
– toxins
• Asymptomatic or short-lived illness
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Biological foodborne illness
• microorganism
• toxin
Types of foodborne illnesses 1. Infection – microorganism
– e.g. Salmonella, Listeria, viruses
2. Intoxication – toxin (fast acting) – e.g. Staphylococcus aureus, some fungi
3. Toxicoinfection – microorganism is ingested, then sporulate or die → toxins released
– e.g. Clostridium perfringens
Foodborne disease symptoms
• Gastroenteritis – Vomiting, diarrhoea, nausea, cramps
– Generally self-limiting
• Non-gastroenteritis foodborne illness: – Hepatitis A – liver (jaundice)
– Listeria – transplacental, meningitis
– Toxoplasma – transplacental
– Clostridium botulinum – botulism (nervous)
– Ciguatera – toxin from algae, nervous
– Mycotoxins – liver cancer, kidney damage
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Factors associated with foodborne disease
• inadequate cooking or re-heating
• improper handling temperature – Cooling or hot holding
• poor personal hygiene – Contamination, infected handlers
• contaminated equipment
• food from unsafe sources
• others
Ray 2004
70%
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http://www.who.int/foodsafety/consumer/5keysmanual/en/index.html
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http://www.who.int/foodsafety/consumer/5keysmanual/en/index.html
Quiz time!
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http://www.who.int/foodsafety/consumer/5keysmanual/en/index.html
Quality systems
• Can’t rely on end-point testing – Need to control the process
• Good manufacturing/hygiene practice (GMP/GHP)
– procedures and quality control
– e.g. times, temperatures, disinfection, hygiene
• HACCP – hazard analysis and critical control point system
– NASA
– systematically identifies specific hazards and develops measures for their control
– adopted in 1990’s
– requires prerequisite programs
Pre-requisites and HACCP
• Equipment and processing plant design
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Wallace and Williams, 2001
Quality systems
HACCP steps: 1. identify potential hazards
• e.g. pathogen growth in food
2. determine the critical control points (CCPs) • e.g. cooling of food following cooking
3. critical limits • e.g. must be below 4°C in less than 3 hours
4. monitoring • e.g. monitor temperature of vessel and food
5. corrective actions • e.g. if outside of critical limits
6. verification procedures for HACCP • e.g. testing, calibration
7. record keeping
CCP identification
• Examples of CCPs
• The retorting operation in a canning plant
• Pasteurization
• Chlorination of cooling water
• The addition of a metal detector to a process line
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http://www.fao.org/docrep/W8088E/w8088e05.htm#module%207%20%20%20determine%20
critical%20control%20points%20%20%20task%207principle%202
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http://www.icd-online.org/an/html/courseshaccp.html
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International alignment
• Codex Alimentarius – established by FAO and WHO in 1963 develops harmonised international food
standards, guidelines and codes of practice to protect the health of the consumers and ensure fair practices in the food trade.
• ISO
– International Organization for Standardization – is the world’s largest developer of voluntary international standards developed by a
network of national standards bodies (163 member countries) – ISO9000 (Quality management) and ISO22000 (Food Safety Management)
• ICMSF
– International Commission on Microbiological Specifications for Foods – to provide timely, science-based guidance to government and industry on appraising and controlling
the microbiological safety of foods. – The primary objectives of ICMSF include:
• 1. Provide the scientific basis for microbiological criteria and to promote principles for their establishment and application.
• 2. Overcome the difficulties caused by nations' varying microbiological standards and analytical methods.
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Recent foodborne illness events
• Microbiological – Meat was focus
– Increase in amount of illness from vegetables/fruits
• 2% [1990] to 16% [2007] in US
• Monitoring systems have been broadened
– Listeria in cantaloupes
– Salmonella peanut butter
– Fenugreek seeds in Germany
• E. coli 0104
• Chemical – Melamine in infant formula in China
– Dioxin in pork
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Hanning et al., 2012
Listeria in cantaloupes (US)
• End of 2011 – Whole cantaloupes (rockmelons)
– 147 ill (143 hospitalised) and 33 deaths
– Most deadly outbreak since 1985
• low frequency, long incubation, high mortality (~20%) - vulnerable populations (pregnant woman, elderly, children, immunocompromised)
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http://www.cdc.gov/listeria/outbreaks/cantaloupes-jensen-
farms/082712/index.html
• Linked to Jensen Farms, Colorado
• Same strains found on cantaloupe and Jensen farms environment – packing shed – Conveyor belt, floor drain (13/39 samples positive for Listeria)
• Listeria is found in soil and manure
Listeria in cantaloupes (US)
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http://www.nytimes.com/2011/10/20/business/listeria-outbreak-traced-
to-colorado-cantaloupe-packing-shed.html?pagewanted=all&_r=0
Listeria in cantaloupes (US)
• FDA investigation of Jensen Farms
• Introduction: – There could have been low level sporadic Listeria monocytogenes in the field where
the cantaloupe were grown, which could have been introduced into the packing facility
– A truck used to haul culled cantaloupe to a cattle operation was parked adjacent to the packing facility and could have introduced contamination into the facility
• Spread: – The packing facility’s design allowed water to pool on the floor near equipment and
employee walkways
– The packing facility floor was constructed in a manner that made it difficult to clean
– The packing equipment was not easily cleaned and sanitized; washing and drying equipment used for cantaloupe packing was previously used for postharvest handling of another raw agricultural commodity
• Growth: – There was no pre-cooling step to remove field heat from the cantaloupes before cold
storage. As the cantaloupes cooled there may have been condensation that promoted the growth of Listeria monocytogenes
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http://www.fda.gov/Food/FoodSafety/CORENetwork/ucm272372.
htm#final
Listeria
• Biofilms – Hard to eradicate with cleaning/disinfectants - persistence
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http://people.cst.cmich.edu/alm1ew/208outlineGrowth.html
Rieu et al., 2008
Salmonella in peanut butter (US)
• Salmonella in peanut butter in the USA – late 2008
– Peanut corporation of America (PCA), Georgia
– 714 cases (9 deaths)
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm58e0129a1.htm http://www.cdc.gov/salmonella/typhimurium/update.html
http://www.cdc.gov/salmonella/typhimurium/update.html
Salmonella in peanut butter
• Poor processing plant hygiene (Georgia or Texas) – Mould on wall and ceiling
– Large holes in roof (bird access)
– Insects near product
– No raw and cooked segregation
– Rodents present
– Not cleaned after Salmonella positive test (several over years)
• Testing problems – Release product without testing or before test results were in
– Re-test product after a positive Salmonella test, then release if negative
• Video*
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Peanut butter outbreak in Australia
• 1996 – >500 ill from Salmonella
– Dirty auger put into production line
– Mouse nest and faeces
– Washed with water, but not sanitised
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Investigating a food poisoning outbreak
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http://www.cdc.gov/outbreaknet/investigations/investigating.html
Investigating a food poisoning outbreak
• 1. Detecting a possible outbreak – surveillance
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www.who.int/foodsafety/publications/foodborne_disease/outbreak_guidelines.pdf
Investigating a food poisoning outbreak
• 2. Defining and finding cases – Epidemic curve
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www.who.int/foodsafety/publications/foodborne_disease/outbreak_guidelines.pdf
Investigating a food poisoning outbreak
• 3. Generating hypotheses – questionnaire
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www.who.int/foodsafety/publications/foodborne_disease/outbreak_guidelines.pdf
Investigating a food poisoning outbreak
• Identification of contaminated meal or food item – Theoretically, the association of illness with a particular food should
correlate perfectly
• i.e. 100% of people who ate the food should get sick & 0% of people who didn’t eat the food should be healthy
– However perfect correlation is rare……but why?
• Resistance and susceptibility of people vary
• Amount of food eaten varies
• Distribution of microbe or toxins in food varies
• The case definition might include some with unrelated illnesses or omit persons with mild illness
• The contaminated food might have cross-contaminated other foods
• False information might be given by interviewees
• Psychosomatic symptoms reported by a few people can distort the picture
Hocking, 2003.
Investigating a food poisoning outbreak
• Cohort studies – relative risk (RR) • e.g. what is the risk (rate) of getting sick for people you ate roast beef as
compared to someone who didn’t eat it?
– Calculated by dividing the rate (risk) of illness in people who ate a food item by the rate of illness in people not eating the same food item
Food No. of people eating food item No. of people not eating food item
RR
ill Well Total % ill ill Well Total % ill
Beef 50 50 100 50 5 95 100 5 10.0
Rice 40 70 110 36 15 75 90 17 2.2
Noodles 30 80 110 27 25 65 90 28 1.0
• People consuming beef have a 10-fold increased risk of being ill compared to those not eating beef
Investigating a food poisoning outbreak
• The higher the RR, the stronger the association – IAFP interpretation:
• RR=1 : no difference in risk of illness between the exposed and unexposed groups
• RR<1 : exposed group has a lower risk of illness than the unexposed group
• RR>1 : exposed group has a higher risk of illness than the unexposed group
– Other interpretation
• >3 (strong association)
• ~2 (moderate association)
• 1-1.5 (weak association)
• <1 (protective effect of food)
Investigating a food poisoning outbreak
• 4. Testing the hypotheses and identifying the source – Sampling, culturing and genotyping
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www.who.int/foodsafety/publications/foodborne_disease/outbreak_guidelines.pdf
Investigating a food poisoning outbreak
• 4. Testing the hypotheses and identifying the source – Genotyping (e.g. PFGE, MLVA)
• PFGE – Pulsed field gel electophoresis – Genomic DNA is digested with rare cutting restriction
enzymes and DNA fragments are separated in a gel – 10-20 large fragments generated (800,000 bp to
10,000 bp) • periodic inversion of electric field
– Can take photo of profile – Band difference due to DNA insertions, deletions & mutations
• Method used by PulseNet (gold standard) – Standardised methods
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www.who.int/foodsafety/publications/foodborne_disease/outbreak_guidelines.pdf
PulseNet International
• PulseNet International is a network of National and regional laboratory networks dedicated to tracking foodborne infections world-wide. Each laboratory utilizes standardized genotyping methods, sharing information in real-time.
• Started in Asia-Pacific in 2002 – Asia-Pacific
• PulseNet participants perform standardized molecular subtyping (or “fingerprinting”) of foodborne disease-causing bacteria to distinguish strains of organisms such as Escherichia coli O157:H7, Salmonella, Shigella, Listeria, Vibrio, Clostridium botulinum & Campylobacter at the DNA level
http://www.pulsenetinternational.org/Pages/default.aspx
http://www.cdc.gov/salmonella/typhimurium/strains_table.html
Part 2 – New approaches to controlling foodborne pathogens
• Current preservatives – Benzoate, nitrites, sulfites
– Chlorine dips for fresh vegetables
• Demand for fewer/no preservatives
• New approaches 1. Alternative ‘natural’ antimicrobials
– bacteriocins (e.g. nisin)
– herb and spice extracts
2. Biological control
– lactic acid bacteria (LAB)
– bacteriophages
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Herb and spice extracts
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• Identify antimicrobial activities of unusual herbs and spice extracts
goraka (Garcinia quaesita)
galangal (Alpinia galanga)
pepper (Piper nigrum)
rosemary (Rosmarinus officinalis)
oregano (Oreganum vulgare)
lemon iron bark (Eucalyptus staigeriana)
mountain pepper (Tasmannia lanceolata)
Weerakkody et al., 2010 Food Control
Herb and spice extracts
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Weerakkody et al., 2010 Food Control
• Analysis and purification of active components
• Typical gas chromatogram of A. galanga hexane extract: • 1,8 cineole 2.6%(1), 4-Allylphenyl acetate 2.71% (2), Beta-Farnesene 9.04%(3), 1’ACA 63.4%(4)
1
4 3
2
Weerakkody et al., 2011 J. Sci. Food & Agric.
Herb and spice extracts
Herb and spice extracts
• Effect of purified 1'-acetoxy-chavicol acetate and crude galangal extract on different bacteria
0
5
10
15
20
25
30
35
40
Different microorganisms
Staphylococcus aureus
Listeria monocytogenes
Escherichia coli
Salmonella
golden S. aureus
Diameter of zone of inhibition (mm)
Weerakkody et al., 2012 Int. J. Ant. Agents.
Herb and spice extracts
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No 1’ACA
With 1’ACA
for 1hr
Weerakkody et al., 2012 Int. J. Ant. Agents.
Herb and spice extracts
0
1
2
3
4
5
6
7
8
9
sigB vraS msrA norA vraD
fold
ch
an
ge
gene
Effect of 1'ACA on stress gene expression in S. aureus
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
0 50 100 150 200 250
OD
at
26
0 n
m
Time (min)
control
0.125ul/ml
1ul/ml
Effect of 1'ACA on cell constituent release of S. aureus
• Investigating the mechanism of action Lysis and cell envelope stress
Weerakkody et al., 2012 Int. J. Ant. Agents.
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Lactic acid bacteria
• Biomining antimicrobial LAB – Can re-apply to food as biocontrol agents
• Isolate ~ 950 LAB isolates from vegetables and fruits
• Screen for antimicrobial activity using agar spot assay
36
19
19
3 3
5
2 Lactococcus
Leuconostoc
Weissella
Carnobacterium
Enterococcus
Staphylococcus
BacillusInhibition of S. Typhimurium
Inhibition of L. monocytogenes
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Lactic acid bacteria
0
1
2
3
4
5
6
7
8
log
cfu
/g le
ttu
ce
day0
day3
day7
Listeria only
Listeria + chlorine
rinse
Listeria + LAB
Listeria + LAB +
chlorine rinse
• L. monocytogenes growth inhibition on lettuce cuts by LAB and or chlorine
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Lactic acid bacteria
8 days
Added Penicillium
Added Penicillium
& LAB
4 days Cottage cheese
Cheong, 2013
Bacteriophage control of Listeria
• Ubiquitous in nature (commonly found on raw agricultural commodities)
• Psychrotrophic pathogen – can grow at 0˚C
• 99% cases of listeriosis are foodborne – Around 30% mortality rate
• Forms biofilms (can persist)
• In Australia - recalls due to L. monocytogenes alone have amounted to 48% of the total number of recalls due to microbiological contamination (zero tolerance)
• Problem in RTE foods (readily killed by cooking or pasteurisation)
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P100 international approvals
• Approved as a food processing aid in: – 2006 – USA (cheese)
– 2007 – USA (all foods – labelling needed, but not from 2011)
– July 2009 - Netherlands
– Sept 2010 – Canada (no objection)
– Levels of between 107 to 109 PFU/g food specified (no labelling required)
– Australia – to be be used with RTE meat and meat products, cheese, fish and fish products, and fruit and vegetables and their products (surface treatment only)
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What are bacteriophages?
• Viruses that infect bacteria – most abundant microorganisms in the biosphere
(1031 phage)
• naturally present in food and water
• up to ~108 phage/g food
– every bacterial species has its own phage
• natural enemies of bacteria
• don’t attack indiscriminately
– genus/species specific
• cannot replicate without host
• do not infect humans, animals or plants
– problem in dairy industry (cheese starters) – but lead to desirable lysis in some cases
Replication cycle
– Growth phases of bacteriophages include:
• absorption of the phage
• phage replication (lytic phage)
• bursting/cell lysis (10-100s)
Lytic phage life cycle
integration into
host DNA
(lysogenic phage)
Detection and quantifying phage
• Plaque assay
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Target bacteria
Phage lysis (plaque)
P100 data
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• Kills 99% of L. monocytogenes strains (1000s tested)
• Tested on surface contaminated cheese first
• L. monocytogenes (7 CFU/cm2) growth at 14˚C up to day 16 and 6˚C afterwards with or without 3x109PFU/ml P100 in smearing solution
Carlton et al., 2005
• L. monocytogenes growth at 6˚C with (▲) and without (●) 3x108PFU/g P100
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Guenther et al., 2009
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SONI AND NANNAPANENI, 2010
Raw salmon fillets
Other foods tested
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P100 (and A511) data
• Food specific – Liquid foods better
• Less diffusion on solid foods - immobilisation
• Bacteria can hide in uneven surface foods
– Some inactivation in vegetables (1-log for A511)
• Organic acids and tannins?
• Dose dependent – Need at least 108 PFU/g or cm2
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Considerations
• Resistance development – No resistance has been observed – Disposal of unsold products
• Treated foods not expected to re-entry the processing facility
• Genome sequence
– Not homology to toxins or allergens – Lytic and non-transducing (no transfer of virulence genes)
• Oral toxicity – Rats fed 1011 PFU P100 – No ill-effects and normal weight gain
• Production – Bioreactor containing Listeria innocua (Risk group 1 – non-pathogenic)
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FSANZ approval
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• FSANZ Standard 1.3.3. (& 1.3.4.) – 11th Oct, 2012 • No labelling required (processing aid)
approved food for use of phage means food that –
(a) is ordinarily consumed in the same state as that in which it is sold; and
(b) is solid; and
(c) is one of the following –
(i) meat;
(ii) meat product;
(iii) fish;
(iv) fish product;
(v) fruit;
(vi) fruit product;
(vii) vegetable;
(viii) vegetable product;
(ix) cheese; and
(d) is not one of the following –
(i) nuts in the shell and whole;
(ii) raw fruits and vegetables that are intended for hulling, peeling or washing by the
consumer.
Summary
• P100 appears to be a safe and useful Listeria controlling agent and has received approval from FSANZ as a processing aid
• For use as a spray or dip for application on solid food products prior to packaging as a complement to existing practices
• Next – phage for Salmonella from Micreos B.V. SalmonelexTM
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Emerging issues/challenges to food safety
• Population growth • Global warming • Global trade
– standards
• Increasing urbanisation – Greater transport & storage of food
• Increasing wealth – Eating out of home (street vendors)
• Safe water and food preparation facilities • Hygiene • Education • Supply chain management
– Each link (grower, packer, transporter, wholesaler, processor, retailer) – ‘farm to folk’ or ‘paddock to plate’ – Traceability
• Lack of resources – Inspection, surveillance, investigation
• Aging populations (more vulnerable) • Demand for fresh minimally processed foods • International travel
• New pathogens and pathogen evolution • Antibiotic resistance
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Pathogen evolution – E. coli
• Germany June 2011 – 4000 cases of illness linked to raw fenugreek sprouts
• 900 cases of HUS
– HUS = haemolytic uremic syndrome (red blood cell destruction and kidney damage)
• 54 deaths
– Unusual findings
1. HUS more frequent (23% of cases; normally 2-7%)
2. HUS onset shorter (5 d; normally 7d)
3. Strain was resistant to cephalosporin antibiotics
4. Strain was not O157:H7
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Pathogen evolution – E. coli
• Whole genome sequencing revealed reasons for enhanced virulence:
1. Has a combination of virulence factors from 2 E. coli groups
• enteroaggregative E. coli (EAEC) – enhanced intestine adherence
• enterohaemorrhogic E. coli (EHEC) – stx toxin
2. Has a plasmid with CTX-M-15 – antibiotic resistance
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Rasko et al., 2011
Karch et al., 2011
Pathogen evolution – E. coli
• Enhanced aggregative adherence to intestinal epithelial cells
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Bielaszewska et al., 2011
Pathogen evolution – E. coli
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EAEC EAEC + stx toxin
EAEC + stx toxin + antibiotic resistance
Hybrid pathogen
Pathogen evolution – E. coli
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But not in sprouts or farms (due to very low infectious dose?)
Karch et al., 2011
Pathogen evolution – E. coli
• Rapid genome sequencing technologies useful for: – Comparing isolates (a new genotyping method)
– Identification of diagnostic targets
– Antibiotic resistance profiling
– Virulence factor profiling
• Hybrid pathogen is not found in animals – Probably a human source (asymptomatic carriers?)
– Antibiotic treatment reduces competition flora - worse
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http://www.invitrogen.com/site/us/en/home/Products-and-
Services/Applications/Sequencing/Semiconductor-Sequencing/pgm.html
Antibiotic resistance
• Used in food animal production – Treat infections
– Growth promoters (sub-inhibitory levels)
• Outweighs human use in many countries
• 2006 – EU bans antibiotics for growth promotion
• Antibiotic resistant Salmonella – Longer illness & hospitalisation
– Higher risk of invasive infection & death
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http://medchrome.com/basic-science/microbiology/antibiotic-resistance-and-factors-for-it-presentation/
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WHO, 2011
Antibiotic resistance
• % of antibiotic resistant isolates from raw meat
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Vietnam China UK USA
Beef Poultry Beef Poultry Beef Poultry Beef Poultry
Salmonella 12% 89% 100% 62%
100% 80%
82% 30% 100%
E. coli 65% 100%
90%
≥24% ≥50%
Van et al., 2007
Van et al., 2008
Yan et al., 2010
Yang et al., 2010
Little et al., 2008
White et al., 2001
Zhao et al., 2010
• Antibiotic resistant bacteria are common in food around the world
Antibiotic resistance
• Regulation and education – Especially ‘last-line’ human antibiotics (e.g. third generation
cephalosporins)
• Surveillance
• Alternatives – Vaccines, probiotics, better hygiene & management practices
• Food hygiene – Reduce transmission to humans
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Summary
• Food safety is a global issue
• Food safety control systems are important
• Surveillance and outbreak investigation resources
• Education and inspection
• New technologies
• Research
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Emerging issues/challenges to food safety
• **Audience activity (if time permits)** – Arrange yourselves into groups of ~5 people
– Try and have a good english speaker in your group
– Introduce yourselves to others in your group and say where you work or are studying and what your position is or what you are studying
– Discuss the following 2 questions over the next 10 minutes:
1. What is one important issue in food safety in Vietnam or in your city?
2. What is something that could be done to improve this one issue?
– A spokesperson from your group will now stand up and present the group’s responses to the 2 questions in 2-3 minutes.
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References
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and herb extracts against selected food-borne bacteria. Food Control, 21(10), 1408-1414. • Weerakkody, N. S., Caffin, N., Lambert, L. K., Turner, M. S., & Dykes, G. A. (2011). Synergistic antimicrobial activity of galangal
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• http://www.lurvely.com/photo/256305654/T4bacteriophage • http://www.slic2.wsu.edu:82/hurlbert/micro101/pages/Chap11.html/ • http://en.wikipedia.org/wiki/Bacteriophage
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References • Weerakkody, N. S., Smith, W. M., Mikkelsen, D., Waanders, J., Kerven, G., Caffin, N., ... & Turner, M. S. (2012). Purified 1'acetoxychavicol acetate (1'ACA)
from galangal spice affects membrane fatty acid composition and triggers a cell envelope stress response in Staphylococcus aureus. International journal of antimicrobial agents, 39(3), 269-272.
• http://www.lurvely.com/photo/256305654/T4bacteriophage • http://www.slic2.wsu.edu:82/hurlbert/micro101/pages/Chap11.html/ • http://en.wikipedia.org/wiki/Bacteriophage • Carlton, R. M., Noordman, W. H., Biswas, B., De Meester, E. D., & Loessner, M. J. (2005). Bacteriophage P100 for control of< i> Listeria
monocytogenes</i> in foods: Genome sequence, bioinformatic analyses, oral toxicity study, and application. Regulatory Toxicology and Pharmacology, 43(3), 301-312.
• Soni, K. A., & Nannapaneni, R. (2010). Bacteriophage significantly reduces Listeria monocytogenes on raw salmon fillet tissue. Journal of Food Protection, 73(1), 32-38.
• Guenther, S., Huwyler, D., Richard, S., & Loessner, M. J. (2009). Virulent bacteriophage for efficient biocontrol of Listeria monocytogenes in ready-to-eat foods. Applied and environmental microbiology, 75(1), 93-100.
• Karch, H. et al. The enemy within us: lessons from the 2011 European Escherichia coli O104:H4 outbreak. EMBO Mol. Med. 4, 841–848 (2012). • Bielaszewska, M., Mellmann, A., Zhang, W., Köck, R., Fruth, A., Bauwens, A., ... & Karch, H. (2011). Characterisation of the< i> Escherichia coli</i> strain
associated with an outbreak of haemolytic uraemic syndrome in Germany, 2011: a microbiological study. The Lancet infectious diseases, 11(9), 671-676. • Rasko, D. A., Webster, D. R., Sahl, J. W., Bashir, A., Boisen, N., Scheutz, F., ... & Waldor, M. K. (2011). Origins of the E. coli strain causing an outbreak of
hemolytic–uremic syndrome in Germany. New England Journal of Medicine, 365(8), 709-717. • Van, T. T. H., Moutafis, G., Tran, L. T., & Coloe, P. J. (2007). Antibiotic resistance in food-borne bacterial contaminants in Vietnam. Applied and
environmental microbiology, 73(24), 7906-7911. • Van, T. T. H., Chin, J., Chapman, T., Tran, L. T., & Coloe, P. J. (2008). Safety of raw meat and shellfish in Vietnam: an analysis of Escherichia coli isolations
for antibiotic resistance and virulence genes. International journal of food microbiology, 124(3), 217-223. • Yan, H., Neogi, S. B., Mo, Z., Guan, W., Shen, Z., Zhang, S., ... & Zhong, N. (2010). Prevalence and characterization of antimicrobial resistance of
foodborne< i> Listeria monocytogenes</i> isolates in Hebei province of Northern China, 2005–2007. International journal of food microbiology, 144(2), 310-316.
• Yang, B., Qu, D., Zhang, X., Shen, J., Cui, S., Shi, Y., ... & Meng, J. (2010). Prevalence and characterization of< i> Salmonella</i> serovars in retail meats of marketplace in Shaanxi, China. International journal of food microbiology, 141(1), 63-72.
• Little, C. L., Richardson, J. F., Owen, R. J., De Pinna, E., & Threlfall, E. J. (2008). < i> Campylobacter</i> and< i> Salmonella</i> in raw red meats in the United Kingdom: Prevalence, characterization and antimicrobial resistance pattern, 2003–2005. Food microbiology, 25(3), 538-543.
• White, D. G., Zhao, S., Sudler, R., Ayers, S., Friedman, S., Chen, S., ... & Meng, J. (2001). The isolation of antibiotic-resistant Salmonella from retail ground meats. New England Journal of Medicine, 345(16), 1147-1154.
• Zhao, S., Blickenstaff, K., Bodeis-Jones, S., Gaines, S. A., Tong, E., & McDermott, P. F. (2012). Comparison of the Prevalences and Antimicrobial Resistances of Escherichia coli Isolates from Different Retail Meats in the United States, 2002 to 2008. Applied and environmental microbiology, 78(6), 1701-1707.
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