Australian Group on Antimicrobial Resistance Australian Staphylococcus aureus Sepsis Outcome Programme annual report, 2014.
From 1 January to 31 December 2014, 27 institutions around Australia participated in the Australian Staphylococcal Sepsis Outcome Programme (ASSOP) The aim of ASSOP 2014 was to determine the proportion of Staphylococcus aureus bacteraemia (SAB) isolates in Australia that are antimicrobial resistant, with particular emphasis on susceptibility to methicillin and to characterise the molecular epidemiology of the isolates. Overall, 18.8% of the 2,206 SAB episodes were methicillin resistant, which was significantly higher than that reported in most European countries. The 30 day all cause mortality associated with methicillin resistant SAB was 23.4% which was significantly higher than the 14.4% mortality associated with methicillin sensitive SAB (P <0.0001) With the exception of the beta lactams and erythromycin, antimicrobial resistance in methicillin sensitive S. aureus remains rare. However in addition to the beta lactams, approximately 50%0 of methicillin resistant S. aureus (MRSA) were resistant to erythromycin and ciprofloxacin and approximately 15% were resistant to co trimoxazole, tetracycline and gentamicin. When applying the European Committee on Antimicrobial Susceptibility Testing breakpoints, teicoplanin resistance was detected in 2 S. aureus isolates. Resistance was not detected for vancomycin or linezolid. Resistance to non beta lactam antimicrobials was largely attributable to 2 healthcare associated MRSA clones; ST22 IV [2B] (EMRSA 15) and ST239 III [3A] (Aus 2/3 EMRSA) ST22 IV [2B] (EMRSA 15) has become the predominant healthcare associated clone in Australia. Sixty per cent of methicillin resistant SAB were due to community associated (CA) clones. Although polyclonal, almost 44% of community associated clones were characterised as ST93 IV [2B] (Queensland CA MRSA) and ST1 IV [2B] (WA1) CA MRSA, in particular the ST45 V [5C2&5] (WA84) clone, has acquired multiple antimicrobial resistance determinants including ciprofloxacin, erythromycin, clindamycin, gentamicin and tetracycline. As CA MRSA is well established in the Australian community it is important that antimicrobial resistance patterns in community and healthcare associated SAB is monitored as this information will guide therapeutic practices in treating S. aureus sepsis.
Communicable diseases intelligence quarterly report