In 2007, Food Regulation Standing Committee commissioned Food Science Australia to conduct a pilot survey of foods for bacteria resistant to antibiotics. This survey forms part of a three pronged approach to national surveillance of antimicrobial resistance covering all areas of antibiotic use (food-producing animals, food and humans). The project was funded by all States and Territories, and the Australian Government. The Australian Government Department of Health and Ageing managed the survey on behalf of FRSC. The survey report, a plain language summary and a questions and answers document relating to the report, are attached.

W/group: FRSC Working Group to Oversee the Survey of AMR in Food
Chair: Commonwealth Government Department of Health and Ageing

Pilot survey for Antimicrobial Resistant (AMR) Bacteria in Australian Food - Part 1 - Executive Summary to Materials and Methods (PDF 172 KB)
Pilot survey for Antimicrobial Resistant (AMR) Bacteria in Australian Food - Part 1 - Executive Summary to Materials and Methods (Word 102 KB)
Pilot survey for Antimicrobial Resistant (AMR) Bacteria in Australian Food - Part 2 - Results (PDF 201 KB)
Pilot survey for Antimicrobial Resistant (AMR) Bacteria in Australian Food - Part 2 - Results (Word 524 KB)
Pilot survey for Antimicrobial Resistant (AMR) Bacteria in Australian Food - Part 3 - Results (PDF 309 KB)
Pilot survey for Antimicrobial Resistant (AMR) Bacteria in Australian Food - Part 3 - Results (Word 183 KB)
Pilot survey for Antimicrobial Resistant (AMR) Bacteria in Australian Food - Part 4 - Discussion to Supplementary file note (PDF 189 KB)
Pilot survey for Antimicrobial Resistant (AMR) Bacteria in Australian Food - Part 4 - Discussion to Supplementary file note (Word 103 KB)

Pilot Survey for Antimicrobial Resistant (AMR) Bacteria in Australian Food: A Report for the Food Regulation Standing Committee: Plain Language Summary

In 2007, Australia’s peak advisory committee on food safety, The Food Regulation Standing Committee commissioned Food Science Australia to conduct a pilot survey of foods for bacteria that were resistant to antibiotics.

The main reason for conducting the pilot survey was to determine the prevalence of antimicrobial resistant (AMR) bacteria in food. Food-borne bacteria, such as Salmonella and Campylobacter, can cause prolonged and more serious infections if they are resistant to antibiotics that are used to treat human infections. In other countries the use of antibiotics in food producing animals has been linked to human infections with AMR bacteria via foods. All antibiotic use, whether in humans or animals can result in bacteria that are resistant to antibiotics.

In this survey, samples of raw whole poultry, beef mince, pork chops and iceberg lettuce were collected each month from shops in Melbourne, Sydney, Brisbane and Perth between February 2007 to January 2008. The food items selected were considered to be representative of an average consumer’s shopping basket. Bacteria were isolated from food samples and then tested by Food Science Australia to see if they were resistant to a range of different antibiotics. All foods tested were of Australian origin.

As this survey focused on resistant bacteria, enough food samples were collected to test 100 samples of bacteria for each food. Food samples were tested for common causes of food-borne gastroenteritis—Salmonella and Campylobacter—and bacteria commonly found in the gut of people and animals—Escherichia coli and Enterococcus faecalis. It was difficult to isolate Escherichia coli at all from lettuce—the only ready to eat food.

In the survey, testing of bacteria isolated from foods indicated that overall resistance to the majority of antibiotics was low. When compared to reports from other countries, Australia has a very low prevalence of bacteria that are resistant to antibiotics on these foods, particularly those “critically important” for human medicine.

The World Health Organization (WHO) defines “critically important” antibiotics as antibacterial agents for which there is potential that their use in humans may be threatened by resistance resulting from their non-human use. Most importantly, the survey found resistance to “critically important” antibiotics to human medicine, such as the quinolone class of drugs and 3rd and 4th generation cephalosporins, was non existent or extremely low in bacteria isolated from foods. For example, the survey found no resistance to ceftriaxone, a WHO “critically important” antibiotic used to treat Salmonella. This means that in Australia these antibiotics remain available for use if by chance someone did get an infection via bacteria acquired through the food chain.

This pilot survey supports Australia’s more rigorous approach to controlling the amounts and types of antibiotics used in our food animal industries, which is an important factor that helps prevent the development and spread of resistant bacteria. It represents a baseline for comparison of future surveys and should reassure public health agencies and consumers about the safety of the Australian food supply.

Pilot Survey for Antimicrobial Resistant (AMR) Bacteria in Australian Food: A Report for the Food Regulation Standing Committee: Questions and Answers Document

The Survey

1. What is the survey?

This pilot survey provides a snapshot of the prevalence and types of AMR bacteria present in selected raw retail foods in Australia. It is the first comprehensive survey of its type in Australia and is intended to provide a baseline to look at trends over time.

This survey supports Australia’s rigorous approach to controlling the amounts and types of antibiotics used in our food animal industries, which is an important factor that helps prevent the development and spread of resistant bacteria.

Raw foods were sampled monthly over a 12 month period (February 2007-January 2008) from retail outlets in Melbourne, Sydney, Brisbane and Perth. Whole poultry, pork chops, beef mince and iceberg lettuce were tested for the presence of Campylobacter, Salmonella, Escherichia coli and Enterococcus and isolates were tested for AMR.

2. What did the survey find?

In the survey, testing of bacteria isolated from raw foods indicated that overall resistance to the majority of antibiotics was low by international comparison. Most importantly, the survey found resistance to “critically important” antibiotics to human medicine, such as the quinolone class of drugs and 3rd and 4th generation cephalosporins, was non existent or extremely low in bacteria isolated from raw foods. For example, the survey found no resistance to ceftriaxone, a WHO “critically important” antibiotic used to treat Salmonella. There was no vancomycin resistant Enterococcus detected. This means that in Australia these antibiotics remain available for use if by chance someone did get an infection via bacteria acquired through the food chain.

3. How comprehensive and accurate is the survey (e.g. there are lines in the report that admit to its shortcomings)

The survey was limited to those raw food/bacterium combinations where the expected prevalence of the target organisms was projected to be greater than 10 percent and the food is extensively consumed by the general population. Four retail foods; poultry, beef, pork and lettuce along with four target organisms; Campylobacter, Salmonella, Escherichia coli and Enterococcus constitute the nine food / bacterium combinations included in the survey.

The survey data cannot be used to directly provide information about the development of AMR. However, it does provide baseline data suitable for future use in the determination of AMR trends at the Australian retail food level.

Due to the small number of Escherichia coli isolated from the lettuce, firm conclusions concerning the prevalence of AMR in lettuce / Escherichia coli isolates cannot be made.

Antimicrobials and AMR

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4. What are antimicrobials?

The terms "antimicrobials" or "antimicrobial agents" refer to all types of natural and synthetic drugs which may kill or slow down the growth of microorganisms. These include antibiotics, anti-fungals, and household disinfectants. Antimicrobial agents are widely used for the treatment and prevention of human and animal diseases.

5. What is AMR?

AMR occurs when a specific antimicrobial drug is ineffective in killing or slowing down the growth of a targeted microorganism. Development of resistance stops or reduces the effectiveness of antimicrobial agents intended to treat human and animal infections.

6. Why is AMR an issue?

The emergence of AMR threatens our ability to fight human and animal diseases with potentially serious public health implications. This could narrow the line of defense against bacterial infections to only a few antibiotics and increase health care costs. Infections caused by AMR bacteria are more difficult to treat often resulting in increased morbidity, increased time in hospital and higher mortality rates.

7. How does AMR develop?

AMR can occur naturally in some types of bacteria when the antimicrobial cannot suppress or kill the particular species of bacteria. It is for this reason that different antimicrobials are used to treat infections caused by different bacteria. Overuse or inappropriate use of antibiotics is considered to be an important contributor to the development of AMR.

The antimicrobial resistance of greatest concern is that which is acquired by bacteria through alterations in their genetic make-up as a result of random changes (mutations) in their DNA or through movement of antimicrobial resistance genes from one bacterium to another. Continued use of an antimicrobial in the face of resistance to it, allows resistant bacteria to survive the treatment and these then become the dominant bacteria in that setting.

8. Why are antimicrobials used in food-producing animals?

Antimicrobials are prescribed and used therapeutically for the treatment of animal diseases. Antimicrobials may be added to the feed of food-producing animals, for example, to prevent infections. However, the antibiotics used under these circumstances are not the kind that would be of importance for treating infections in humans.
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9. What do farm animals have to do with AMR?

The use and overuse of antibiotics, whether in humans or animals can result in bacteria that are resistant to antibiotics. Antibiotics are used in animals to control infection but there are many regulations and codes of good practice that govern their use.

All antibiotic products used in all animals, including dairy cattle, must be registered by the Australian Pesticides and Veterinary Medicines Authority (APVMA). The APVMA’s governing legislation states that the APVMA must not register any product that is harmful to people, animals, crops or the environment. The states and territories control the use of registered products in their jurisdiction.

In addition, there are third-party independently audited industry quality assurance programs that require participating producers to follow good agricultural practices in the use of agricultural chemicals and veterinary drugs, including antibiotics. Further, the National Residue Survey (NRS) monitors and reports the levels of residues of veterinary drugs (including residues of antibiotics) in meat. NRS provides results of testing to the participating primary industries to assist them to monitor and prevent chemical residues in products from those industries.

10. How is AMR spread?

AMR bacteria can be spread from person to person through direct contact with infectious material, poor hygiene or poor infection control, for example, in hospitals. It is also possible for resistant enteric (gut) bacteria to be passed from animals to humans where there is poor hygiene and sanitation.

While the risk of infection from bacteria in food is very low, appropriate food handling, hygiene, storage and preparation further reduce this risk. These practices are particularly important when dealing with pregnant women, the elderly, young children and anyone with an illness.

11. Can antimicrobial residues in food lead to antimicrobial resistance?

No, one of the findings of the Joint Expert Technical Advisory Committee on Antibiotic Resistance (JETACAR) Report was that it was highly unlikely that the consumption of antibiotic residues in food would lead to the development of resistance. This is because antibiotic residue levels in food are already very low and are likely to be further reduced by cooking and other food processing and also by metabolism in the gut.

12. Is the Australian food supply safe?

Australia’s food supply is one of the safest and cleanest in the world¹.

Bacteria are ubiquitous in every habitat on Earth, as well as in organic matter and the live bodies of plants and animals. Although the vast majority of these bacteria are rendered harmless by the protective effects of the immune system, and a few are beneficial, some are pathogenic bacteria and cause infections.

The prevalence of bacteria in raw meat and lettuce tested in this survey was as anticipated.

While the risk of infection from bacteria in raw food is very low, appropriate food handling, hygiene, storage and preparation further reduce this risk. These practices are particularly important when dealing with pregnant women, the elderly, young children and anyone with an illness.

All foods, including imported food, must comply with the Food Standards Code, which includes Maximum Residue Limits (MRLs) for antimicrobial residues. Standard 1.4.2 in the Food Standards Code list the maximum permissible limits for antibiotic residues in food. Food legislation makes it illegal for food to be sold if it contains residues in excess of these limits. These limits are the maximum residues that could result if an antibiotic is used legally (they do not represent the residues that are always present in the food we eat and in most cases the residues are very much lower)².

The 2007/2008 the National Residue Survey monitoring program found that in 3,364 samples of beef, sheep meat, pork, chicken and game meat tested, 24 (0.71 %) had residues of antibiotics, with only two (0.06%) having residues above the maximum permissible limit.

13. What can people do to reduce their risk of exposure to AMR bacteria in food?

Proper food handling and food preparation minimises the risk of all bacteria, including AMR bacteria, being transmitted from food to humans. People should maintain an awareness of food safety risks and encourage good food safety practices. The simple actions outlined below can reduce the likelihood of food poisoning drastically

• Clean hands and wash utensils and cutting boards with soap and warm water , and dry thouroughly before handling different sorts of foods;
• Chill food that is meant to be kept chilled. Refrigerate leftovers promptly and frozen foods should be defrosted in the fridge not on the kitchen bench;
• Cook chicken, minced or boned meats, hamburger, stuffed meats and sausages right through until juices are clear. Serve hot food steaming hot >60ºC and always follow cooking instructions on packaged foods; and
• Separate – Cross contamination is a major way for food borne diseases to spread. Keep raw and cooked foods separate when storing and preparing.

Further food safety information is available from the Food Safety Information Council (FSIC). FSIC is a non-profit organisation that educates consumers in safe food handling practices.

1 Food Standards Australia New Zealand. 2003. Food Standards: The 20th Australian Total Diet Survey,
http://www.foodstandards.gov.au/foodmatters/antibioticsandfood.cfm