Antimicrobial resistance in Staphylococcus aureus

Antimicrobial resistance occurs when some of the bacteria that cause infections resist the effects of antimicrobials used to treat them. This may lead to ‘treatment failure’, or the inability to treat the cause of the infection (Department of Health, 2020).  Methicillin is an antimicrobial used to treat SABSI.

A bloodstream infection that is identified by a laboratory as being caused by a methicillin-resistant strain of S. aureus is referred to as MRSA. A bloodstream infection that is identified by a laboratory as being caused by a S. aureus strain that is methicillin-sensitive is referred to as MSSA.

A bloodstream infection caused by MRSA may cause more harm to patients and is associated with poorer patient outcomes as there are fewer antimicrobials available to treat the infection.

The analysis and monitoring of SABSI resistance to antimicrobials can inform strategies regarding the appropriate prescribing of antimicrobials with the aim of reducing resistance and adverse effects on patients.

Antimicrobial Use and Resistance in Australia (AURA) Surveillance System

The Antimicrobial Use and Resistance in Australia (AURA) Surveillance System publishes data on antimicrobial prescribing in hospitals and rates of MRSA in Australia. Overall, more than 24% of antimicrobial prescriptions in Australian hospitals were assessed as inappropriate (National Centre for Antimicrobial Stewardship and ACSQHC 2021). Methicillin resistance in S. aureus has been stable from 2013–2019 (Coombs et al. 2021).

References

Australian Commission on Safety and Quality in Health Care (ACSQHC), 2018. Australian Passive Antimicrobial Resistance Surveillance First report: multi-resistant organisms. Sydney: ACSQHC. Viewed 12 Nov 2020.

Coombs G, Bell JM, Daley D, Collignon P, Cooley L, Gottlieb T, Iredell J, Kotsanas D, Nimmo G and Robson J on behalf of the Australian Group on Antimicrobial Resistance and the Australian Commission on Safety and Quality in Health Care. 2021. Australian Group on Antimicrobial Resistance Sepsis Outcome Programs: 2019 Report. Sydney: ACSQHC. Viewed 12 Nov 2020.

Department of Health, 2020. Antimicrobial Resistance, About AMR. Viewed 12 Nov 2020.

National Centre for Antimicrobial Stewardship and ACSQHC, 2021. Antimicrobial prescribing practice in Australian hospitals: results of the 2019 Hospital National Antimicrobial Prescribing Survey. Sydney: ACSQHC.