Tackling antimicrobial resistance in the food chain

What is AMR, and why does it matter?

Antimicrobial resistance (AMR) is widely regarded as presenting a growing risk to human health. Resistance of pathogenic bacteria to antimicrobials – particularly antibiotics – threatens the prevention and treatment of illnesses and infections. If this trend goes unchecked, more people will die from common illnesses and foodborne diseases.

In response to this, the use of antibiotics by the medical profession is under scrutiny, and attention is also being turned to the food chain. In a November 2017 report on antimicrobial resistance in the food chain, The World Health Organization (WHO) says:

The high volume of antibiotics in food-producing animals contributes to the development of antimicrobial-resistant bacteria, particularly in settings of intensive animal production. In some countries, the total amount of antibiotics used in animals is 4 times larger than the amount used in humans. In many countries much of the antibiotics used in animals are for growth promotion and prevention of disease, not to treat sick animals.

These bacteria can be transmitted from animals to humans via direct contact between animals and humans, or through the food chain and the environment. Antimicrobial-resistant infections in humans can cause longer illnesses, increased frequency of hospitalization, and treatment failures that can result in death.

AMR study focusing on ready-to-go food

In 2016, I was involved in an academic study investigating the occurrence of microbes – and their antibiotic resistance – in 52 ready-to-go foods obtained from local grocery stores. The items tested included canned and bagged products as well as glass jars of baby food.

The food packaging was sterilized, then samples of the contents were taken and microbial occurrence was observed using a growth enrichment method. The resultant microorganisms were isolated and extracted, ready for antibiotic resistance screening.

The resistance of 112 isolates was examined against commonly used antibiotics, such as ampicillin, streptomycin, chloramphenicol and kanamycin at varying concentrations. We observed resistance to ampicillin across 64 isolates and resistance to chloramphenicol across 18 isolates. Overall, isolates from bagged foods showed greater antibiotic resistance than those from canned and baby foods.

Most of the microorganisms we observed were not pathogenic. However, the resistance to antibiotics was significant. The ability of these microorganisms to survive the harsh food processing or preservation techniques they had encountered was also noteworthy.

The findings indicate that people may be being exposed to antimicrobial resistant microorganisms via their daily food intake. It is vital that steps are taken to address this and eliminate potential antimicrobial resistance in humans.

Industry best practice

This issue affects people of all ages and in all societies. Food manufacturers need to take it seriously and address it proactively, rather than waiting for regulatory measures to instigate change. Best practice involves conducting due diligence on raw materials, particularly animal products. Knowing the provenance of products is vital, and in the case of meat, poultry and dairy products, attention should be paid to the full spectrum of husbandry, from veterinary care to sources of animal feed. This requires active engagement between food producers and farmers, with external guidance and verification to ensure antimicrobial resistant bacteria are at safe and acceptable levels.

Follow the link to read the full paper – Microbial occurrence and antibiotic resistance in ready-to-go food items – published in the Journal of Food Science and Technology.