Evolution of resistance in Staphylococcus aureus in Australian teaching hospitals. Australian Group on Antimicrobial Resistance (AGAR).
OBJECTIVE
To assess the changes in antibiotic resistances in Staphylococcus aureus, both methicillin-susceptible and methicillin-resistant strains, in Australia.


METHODS
Retrospective review of data collected annually.


METHODS
Twenty metropolitan teaching hospitals in the six States of Australia and the Australian Capital Territory from 1988 to 1994.


METHODS
Changes in prevalence and resistance rates of methicillin-resistant S. aureus (MRSA) and methicillin-susceptible strains, based on antibiotic susceptibility testing of clinical isolates of S. aureus.


RESULTS
Prevalence of MRSA has remained constant on the eastern seaboard of Australia. A distinctive strain of MRSA emerged in Western Australia which had different antimicrobial susceptibilities. Resistances emerged in MRSA strains from eastern Australia, principally to ciprofloxacin and rifampicin, while resistance to fusidic acid remained stable and resistance to chloramphenicol significantly declined. Resistances in methicillin-susceptible strains remained fairly stable, except for a decline in resistance levels for tetracycline. High levels of resistance were seen to penicillin, moderate levels to erythromycin and low levels to trimethoprim and fusidic acid in methicillin-susceptible strains.


CONCLUSIONS
The continued high prevalence of and increasing resistance in MRSA in some Australian hospitals have meant that some strains are now untreatable with oral antibiotics.
Turnidge
J D
JD
Microbiology and Infectious Diseases Department, Monash Medical Centre, Clayton, Victoria.
Nimmo
G R
GR
Francis
G
G
D001315:Australia / Q000453:epidemiology; D002939:Ciprofloxacin / Q000494:pharmacology; D003428:Cross Infection / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D004352:Drug Resistance, Microbial; D006784:Hospitals, Teaching / Q000706:statistics & numerical data*; D006801:Humans; D008712:Methicillin / Q000494:pharmacology / Q000627:therapeutic use; D016106:Methicillin Resistance; D010406:Penicillins / Q000494:pharmacology / Q000627:therapeutic use; D012189:Retrospective Studies; D012293:Rifampin / Q000494:pharmacology / Q000627:therapeutic use; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects*
D010406:Penicillins; D002939:Ciprofloxacin; D008712:Methicillin; D012293:Rifampin