Multidrug-resistant organisms (MRO)

Antimicrobial resistance amongst microorganisms that commonly cause infections in healthcare settings is a growing problem worldwide. A recently emerging example is outbreaks of healthcare associated infection with a yeast called Candida auris, which is resistant to many antifungal agents.

Infections with MROs are more difficult to treat, and are associated with poorer outcomes for patients and increased costs to the health care system.

What causes antimicrobial resistance?

Antimicrobial resistance occurs as a direct result of antibiotic treatment, and is driven by the increasing consumption of antimicrobials as a result of several factors, such as:

  • the increased use of invasive medical treatments
  • the use of immune suppressive agents in the treatment of cancer
  • more complex surgical procedures
  • an ageing population with lowered immunity to infection
  • consumption of antibiotics present in the food chain.

Most problematic antibiotic-resistant bacteria in health care facilities

The antibiotic-resistant bacteria that cause the most problems for patients in health care facilities are:


The prevention of infection with antimicrobial-resistant bacteria involves the simultaneous application of a number of strategies:


All types of MRO are managed with transmission-based precautions that are tailored to the route of transmission for the particular organism under consideration. A risk-based approach should always be taken in deciding the level of precautions, and whether or not a patient needs to be isolated. 

For the current best practice in the management of patients colonised and infected with MROs in the acute and non-acute care settings, refer to:

Further information

For further information on the management of MRO contact SA Health's Infection Control Service.

Clinical information in this section