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.  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.

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

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

• Methicillin-resistant Staphylococcus aureus (MRSA)
• Vancomycin-resistant enterococci (VRE)
• Linezolid-resistant enterococci (LRE) and Linezolid-resistant Vancomycin-resistant enterococci (LRVRE) are emerging MROs; transmission based precautions and clearance recommendations are the same as for VRE
  
• Multi-resistant Gram-negative bacilli (MRGN)

• • Carbapenemase-producing Enterobacterales (formerly known as Carbapenemase-producing Enterobacteriaceae)
    

• Candida auris

Prevention

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

• identification of carriage (screening of high risk patient groups) and appropriate inpatient placement, for example single room for patients that pose a high risk of transmission (PDF 225KB)
• diligent hand hygiene practices, including alcohol-based hand rubs at point of care
• application of personal protective equipment when performing patient care activities
• appropriate cleaning and disinfection of patient surroundings and medical equipment
• antimicrobial stewardship – making sure that antibiotics are prescribed appropriately.

Management

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:

• MRSA clinical guideline (PDF 767KB)
• MRGN clinical guideline (PDF 481KB)
• VRE clinical guideline (PDF 383KB)
• Bed management toolkit (PDF 223KB)

Further information

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