Global Food Safety_2013

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Global Food Safety_2013

  1. 1. 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: m.turner2@uq.edu.au
  2. 2. 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 CRICOS Provider No 00025B
  3. 3. 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.
  4. 4. 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
  5. 5. 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 CRICOS Provider No 00025B
  6. 6. 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 CRICOS Provider No 00025B http://www.who.int/features/factfiles/food_safety/en/index.html
  7. 7. 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 CRICOS Provider No 00025B
  8. 8. ‘Tip of the iceburg’ CRICOS Provider No 00025B • Reporting of illness Seen by doctor – not reported Notified – samples positive Mild or asymptomatic Serious symptoms - no medical attention Forsythe 2000.
  9. 9. 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
  10. 10. 1. Foodborne illness http://www.ozfoodnet.gov.au/internet/ozfoodnet/publishing.nsf/Co ntent/annual-cost-foodborne-illness.htm
  11. 11. 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 CRICOS Provider No 00025B
  12. 12. CRICOS Provider No 00025B
  13. 13. The top foodborne pathogens • Most (50-70%) foodborne gastroenteritis is due to unknown pathogens • US (91%), UK (94%), Australia (90%) CRICOS Provider No 00025B Sallam et al., 2011; Adak et al., 2005; Hall et al., 2005 0 10 20 30 40 50 60 70 % USA UK Australia
  14. 14. Bias in results/estimates • Notifiable organisms – Different for different countries • Testing regime and methods – viruses – toxins • Asymptomatic or short-lived illness CRICOS Provider No 00025B
  15. 15. 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
  16. 16. 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 CRICOS Provider No 00025B
  17. 17. 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%
  18. 18. CRICOS Provider No 00025B http://www.who.int/foodsafety/consumer/5keysmanual/en/index.html
  19. 19. CRICOS Provider No 00025B http://www.who.int/foodsafety/consumer/5keysmanual/en/index.htm
  20. 20. Quiz time! CRICOS Provider No 00025B http://www.who.int/foodsafety/consumer/5keysmanual/en/index.html
  21. 21. 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
  22. 22. Pre-requisites and HACCP • Equipment and processing plant design CRICOS Provider No 00025B Wallace and Williams, 2001
  23. 23. 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
  24. 24. 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 CRICOS Provider No 00025B http://www.fao.org/docrep/W8088E/w8088e05.htm#module%207%20%20%20determine%20 critical%20control%20points%20%20%20task%207principle%202
  25. 25. CRICOS Provider No 00025B http://www.icd-online.org/an/html/courseshaccp.html
  26. 26. CRICOS Provider No 00025B
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  29. 29. 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. CRICOS Provider No 00025B
  30. 30. 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 CRICOS Provider No 00025B Hanning et al., 2012
  31. 31. 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) CRICOS Provider No 00025B http://www.cdc.gov/listeria/outbreaks/cantaloupes-jensen- farms/082712/index.html
  32. 32. • 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) CRICOS Provider No 00025B http://www.nytimes.com/2011/10/20/business/listeria-outbreak-traced- to-colorado-cantaloupe-packing-shed.html?pagewanted=all&_r=0
  33. 33. 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 CRICOS Provider No 00025B http://www.fda.gov/Food/FoodSafety/CORENetwork/ucm272372. htm#final
  34. 34. Listeria • Biofilms – Hard to eradicate with cleaning/disinfectants - persistence CRICOS Provider No 00025B http://people.cst.cmich.edu/alm1ew/208outlineGrowth.html Rieu et al., 2008
  35. 35. 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
  36. 36. http://www.cdc.gov/salmonella/typhimurium/update.html
  37. 37. 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* CRICOS Provider No 00025B
  38. 38. 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 CRICOS Provider No 00025B
  39. 39. Investigating a food poisoning outbreak CRICOS Provider No 00025B http://www.cdc.gov/outbreaknet/investigations/investigating.html
  40. 40. Investigating a food poisoning outbreak • 1. Detecting a possible outbreak – surveillance CRICOS Provider No 00025B www.who.int/foodsafety/publications/foodborne_disease/outbreak_guidelines.pdf
  41. 41. Investigating a food poisoning outbreak • 2. Defining and finding cases – Epidemic curve CRICOS Provider No 00025B www.who.int/foodsafety/publications/foodborne_disease/outbreak_guidelines.pdf
  42. 42. Investigating a food poisoning outbreak • 3. Generating hypotheses – questionnaire CRICOS Provider No 00025B www.who.int/foodsafety/publications/foodborne_disease/outbreak_guidelines.pdf
  43. 43. 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.
  44. 44. 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
  45. 45. 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)
  46. 46. Investigating a food poisoning outbreak • 4. Testing the hypotheses and identifying the source – Sampling, culturing and genotyping CRICOS Provider No 00025B www.who.int/foodsafety/publications/foodborne_disease/outbreak_guidelines.pdf
  47. 47. 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 CRICOS Provider No 00025B www.who.int/foodsafety/publications/foodborne_disease/outbreak_guidelines.pdf
  48. 48. 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
  49. 49. http://www.cdc.gov/salmonella/typhimurium/strains_table.html
  50. 50. 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 CRICOS Provider No 00025B
  51. 51. Herb and spice extracts CRICOS Provider No 00025B • 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
  52. 52. Herb and spice extracts CRICOS Provider No 00025B Weerakkody et al., 2010 Food Control
  53. 53. • 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 43 2 Weerakkody et al., 2011 J. Sci. Food & Agric. Herb and spice extracts
  54. 54. 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.
  55. 55. Herb and spice extracts CRICOS Provider No 00025B No 1’ACA With 1’ACA for 1hr Weerakkody et al., 2012 Int. J. Ant. Agents.
  56. 56. Herb and spice extracts 0 1 2 3 4 5 6 7 8 9 sigB vraS msrA norA vraD foldchange 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 ODat260nm 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.
  57. 57. CRICOS Provider No 00025B 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
  58. 58. CRICOS Provider No 00025B Lactic acid bacteria 0 1 2 3 4 5 6 7 8 logcfu/glettuce 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
  59. 59. CRICOS Provider No 00025B Lactic acid bacteria 8 days Added Penicillium Added Penicillium & LAB 4 daysCottage cheese Cheong, 2013
  60. 60. 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) CRICOS Provider No 00025B
  61. 61. 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) CRICOS Provider No 00025B
  62. 62. 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
  63. 63. 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)
  64. 64. Detection and quantifying phage • Plaque assay CRICOS Provider No 00025B Target bacteria Phage lysis (plaque)
  65. 65. P100 data CRICOS Provider No 00025B • 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
  66. 66. • L. monocytogenes growth at 6˚C with (▲) and without (●) 3x108PFU/g P100 CRICOS Provider No 00025B Guenther et al., 2009
  67. 67. CRICOS Provider No 00025B SONI AND NANNAPANENI, 2010 Raw salmon fillets
  68. 68. Other foods tested CRICOS Provider No 00025B
  69. 69. 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 CRICOS Provider No 00025B
  70. 70. 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) CRICOS Provider No 00025B
  71. 71. FSANZ approval CRICOS Provider No 00025B • 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.
  72. 72. 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 CRICOS Provider No 00025B
  73. 73. 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 CRICOS Provider No 00025B
  74. 74. 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 CRICOS Provider No 00025B
  75. 75. 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 CRICOS Provider No 00025B Rasko et al., 2011 Karch et al., 2011
  76. 76. Pathogen evolution – E. coli • Enhanced aggregative adherence to intestinal epithelial cells CRICOS Provider No 00025B Bielaszewska et al., 2011
  77. 77. Pathogen evolution – E. coli CRICOS Provider No 00025B EAEC EAEC + stx toxin EAEC + stx toxin + antibiotic resistance Hybrid pathogen
  78. 78. Pathogen evolution – E. coli CRICOS Provider No 00025B But not in sprouts or farms (due to very low infectious dose?) Karch et al., 2011
  79. 79. 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 CRICOS Provider No 00025B http://www.invitrogen.com/site/us/en/home/Products-and- Services/Applications/Sequencing/Semiconductor-Sequencing/pgm.html
  80. 80. 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 CRICOS Provider No 00025B http://medchrome.com/basic-science/microbiology/antibiotic-resistance-and-factors-for-it-presentation/
  81. 81. CRICOS Provider No 00025B WHO, 2011
  82. 82. Antibiotic resistance • % of antibiotic resistant isolates from raw meat CRICOS Provider No 00025B 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
  83. 83. 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 CRICOS Provider No 00025B
  84. 84. Summary • Food safety is a global issue • Food safety control systems are important • Surveillance and outbreak investigation resources • Education and inspection • New technologies • Research CRICOS Provider No 00025B
  85. 85. 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. CRICOS Provider No 00025B
  86. 86. References • World Health Organization WHO global strategy for food safety: safer food for better health. Geneva: The Organization; 2002. • Scallan, E. et al. Foodborne illness acquired in the United States — major pathogens, Emerging Infectious Diseases 17, 7-15 (2011) • Adak GK, Meakins SM, Yip H, Lopman BA, O’Brien SJ. Disease risks from foods, England and Wales, 1996–2000. Emerg Infect Dis. 2005;11:365–72. • Hall & Kirk 2005. Foodborne illness in Australia: annual incidence circa 2000 • Hall G, Kirk MD, Becker N, Gregory JE, Unicomb L, Millard G, et al. Estimating foodborne gastroenteritis, Australia. Emerg Infect Dis. 2005;11:1257–64. • Ray, Bibek. Fundamental food microbiology. CRC PressI Llc, 2004 • http://www.who.int/foodsafety/consumer/5keysmanual/en/index.html • http://www.who.int/trade/glossary/story028/en/ • Hanning, I. B., O'Bryan, C. A., Crandall, P. G. & Ricke, S. C. (2012) Food Safety and Food Security. Nature Education Knowledge 3(10):9 • http://www.who.int/foodsafety/publications/foodborne_disease/fdbmanual/en/index.html • Aurélie Rieu, Jean-Paul Lemaître, Jean Guzzo, Pascal Piveteau, Interactions in dual species biofilms between Listeria monocytogenes EGD-e and several strains of Staphylococcus aureus, International Journal of Food Microbiology, Volume 126, Issues 1–2, 15 August 2008, Pages 76-82. • Hocking A. 2003. Foodborne microorganisms of public health significance. 6th Ed. AIFST. (Chapter 4) • Weerakkody, N. S., Caffin, N., Turner, M. S., & Dykes, G. A. (2010). < i> In vitro</i> antimicrobial activity of less-utilized spice 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 (Alpinia galanga), rosemary (Rosmarinus officinalis) and lemon iron bark (Eucalyptus staigerana) extracts. Journal of the Science of Food and Agriculture, 91(3), 461-468. • http://www.lurvely.com/photo/256305654/T4bacteriophage • http://www.slic2.wsu.edu:82/hurlbert/micro101/pages/Chap11.html/ • http://en.wikipedia.org/wiki/Bacteriophage CRICOS Provider No 00025B
  87. 87. 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. CRICOS Provider No 00025B

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