About antibiotic resistance
What is antibiotic resistance?
Antibiotic resistance is when bacteria change so that the antibiotics we rely on no longer kill them or stop them growing. It is one of the biggest threats to modern medicine, and how we use antibiotics still shapes how fast it spreads.
Scope: This site is about antibacterial (antibiotic) resistance. Antimicrobial resistance is the broader term that also covers viruses, fungi and parasites; we focus specifically on bacteria.
How resistance develops
The biology, simplyBacteria multiply quickly, and small genetic changes happen naturally as they do. When a population of bacteria meets an antibiotic, most are killed, but any that happen to carry a change that lets them survive are left behind. Those survivors multiply, and can pass their resistance to other bacteria.1
This is ordinary evolution, sped up. It means resistance is not a matter of if but of how fast, and the pace depends heavily on how much antibiotics are used and how well they are used.
What causes and drives resistance
The main drivers are well understood:
- Taking antibiotics when they are not needed, for example for viral infections.
- Not taking them as prescribed, or using leftover or shared medicines.
- Use in animals and agriculture, where antibiotics are also used to treat disease.
- Spread of resistant bacteria between people, animals and the environment, the idea behind One Health.
The One Health connection
Human health, animal health and the environment are linked. Resistant bacteria and the genes that carry resistance move between all three, through food, water and direct contact. Tackling resistance in only one setting is not enough, which is why Australia's approach spans human health, veterinary medicine, agriculture and the environment.3
Common resistant bacteria in Australia
Several resistant bacteria are tracked closely through national surveillance. They include MRSA (methicillin-resistant Staphylococcus aureus), VRE (vancomycin-resistant enterococci), resistant E. coli andKlebsiella, carbapenemase-producing Enterobacterales (CPE), and drug-resistant gonorrhoea. You can see current figures on ourstatistics for Australia page.
Why it matters: the consequences
Antibiotics underpin far more than treating a chest infection. Surgery, chemotherapy, intensive care and care of premature babies all rely on being able to prevent and treat bacterial infections. As resistance grows, routine procedures carry more risk, and some infections become very hard to treat.2
General practitioner and antimicrobial stewardship lead. Reviewed 3 July 2026 · Next review due July 2027 ·View reviewer profile and credentials
Where to next
Keep readingThe Australian data
Resistance and prescribing figures from AURA and national surveillance.
Preventing resistance
The everyday actions that slow resistance down.
Using antibiotics safely
Our plain-language guide to using antibiotics well.
References
- World Health Organization. Antimicrobial resistance: fact sheet. WHO, Geneva, 2023.
- Australian Commission on Safety and Quality in Health Care. AURA 2023: Fourth Australian report on antimicrobial use and resistance in human health. ACSQHC, Sydney, 2023.
- Australian Government Department of Health and Aged Care. One Health and antimicrobial resistance. Canberra, 2023.