Antibiotics and resistance

Learn about bacteria developing resistance to antibiotics, and how antibiotic resistance can be managed.

Antibiotic resistance in bacteria

Antibiotics are medicines that fight bacterial infections in humans and animals. They kill bacteria, or prevent them from growing. However, some bacteria have evolved to be resistant to antibiotics. This can happen through:

  • natural mutation, or
  • exposure to specific chemicals or antibiotics.

If bacteria develop resistance, it means certain antibiotics do not kill them anymore. Because of this:

  • some diseases that were once well controlled are on the rise – like human tuberculosis
  • antibiotic resistant bacteria can now be found in hospitals.

It's important to use antibiotics responsibly to help prevent resistant bacteria from developing.

Managing and preventing antimicrobial resistance (AMR)

"Antimicrobials" are medicines and substances that are used to fight:

  • bacteria
  • non-bacterial pathogens (like fungi, viruses, and protozoa).

Antimicrobials include antibiotics (which only fight against bacteria).

Most attention is focused on resistance of bacteria to antibiotics. However, resistance of the other non-bacterial pathogens is also a focus.

In April 2017, the Ministry of Health (MOH) and the Ministry for Primary Industries (MPI) jointly published a report to respond to the changing pattern of AMR in New Zealand. This was part of a global response.

What the report covers

The report highlights 5 key objectives. These include:

  • improving awareness and understanding of AMR
  • improving prevention and control measures for AMR.

The report also highlighted the need for better data about antibiotic consumption in New Zealand.

Download the report

The report is available on the MOH website.

Action plan to minimise antimicrobial resistance

Following the report, an action plan was developed. This has been finalised. The plan outlines activities under 5 objectives. MPI and MOH will implement these with partners.

New Zealand antimicrobial resistance action plan [PDF, 535 KB]

Government media release about the report – Beehive

Monitoring antibiotic resistance

Limited overseas evidence indicates that in some cases, antibiotic use in animals may contribute to antibiotic resistance in humans. Since 1972, MOH has monitored antibiotic resistance for the main disease-causing microorganisms.

There is no evidence so far that in-feed antibiotics have led to resistance. Despite this, evidence of these trends is continually monitored. If evidence shows a link, controls on antibiotic use in animals will be changed.

One of our main monitoring programmes monitors the sale of agricultural compounds containing antibiotics used in:

  • horticulture
  • veterinary medicines for animals.

The trends around sale of these products are monitored. This is to ensure the regulatory controls on antibiotics are effective and that any significant or concerning changes can be investigated.

Find out more

Controlling and preventing antimicrobial resistance (AMR)

Information sheet: Antibiotic resistance [PDF, 295 KB]

Antimicrobial resistance – Ministry of Health

WHO’s first global report on antibiotic resistance reveals serious, worldwide threat to public health – World Health Organization

Antibiotic use in animals

Like humans, animals sometimes need antibiotics. Most antibiotics can only be used to:

  • treat animals that show symptoms of disease
  • prevent sickness if there's a high risk to the animal.

We do not allow antibiotics of human health importance to be used on animals for growth promotion.

Controls on antibiotic use in food animals

Use of antibiotics in animals is regulated under the Agricultural Compounds and Veterinary Medicines Act 1997.

Agricultural Compounds and Veterinary Medicines Act 1997 – NZ Legislation

After animals are treated with antibiotics, they cannot be slaughtered or supply milk or eggs until the "withholding period" has passed.

The withholding period is the period of time needed for the animal's body to clear medicine residues to below a certain level. The level is known as the "maximum residue level" (MRL). The MRL is set to make sure:

  • medicines used in animals are used appropriately
  • food from that animal is safe to eat.

How safe levels are set for chemical residues in food

When antibiotic levels are below the MRL, it also ensures that the remaining antibiotic level is too low to contribute to antibiotic resistance.

Regulation of veterinary antibiotics in New Zealand

Before veterinary antibiotics can be used in animals, they must be registered under the ACVM Act 1997. The antibiotics are thoroughly assessed first. This ensures they can be used safely and effectively in animals. If they're used in food-producing animals, MPI must also be satisfied that the antibiotic will not leave residues above the MRL in food from the treated animals.

Agricultural Compound and Veterinary Medicine (ACVM) registration process

It's important to restrict access to antibiotics that are important to animal and human health. To use these antibiotics, a veterinary prescription is needed.

All antibiotics registered for use in animals in New Zealand are assessed before they're approved. There is a thorough review criteria for this. They are reviewed for veterinary use and human health significance as agreed with MOH. MPI must also be satisfied that use of the antibiotic will not leave unsafe residues in food.

Who to contact

If you have questions about antibiotic resistance, email

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