Antimicrobial activity and spectrum of daptomycin: Results from the surveillance program in Australia and New Zealand (2008)

Abstract

Aims: To assess invitro activity and spectrum of daptomycin, a new lipopeptide antimicrobial, against contemporary isolates of Gram positive pathogens in Australia and New Zealand in 2008. Methods: Gram positive isolates from patients with a range of bacterial infections served by seven Australian and three New Zealand laboratories were tested by broth microdilution and susceptibility results interpreted using current Clinical and Laboratory Standards Institute (CLSI) standards against daptomycin and a range of comparator agents including oxacillin, vancomycin and linezolid. Results: 872 Staphylococcus aureus (24.0% oxacillin resistant; Australia 28.4%, New Zealand 9.0%), 60 coagulase negative staphylococci (83.3% oxacillin resistant), 113 Enterococcus species (6.2% vancomycin non-susceptible), 40 viridans group Streptococcus species (7.5% penicillin resistant), and 158 β-haemolytic Streptococcus species were tested. Daptomycin was active against all 1243 strains, and no resistance or reduced susceptibility was detected, including among multi-resistant strains and those resistant to vancomycin. Conclusions: At the time of the introduction of daptomycin into clinical practice in Australia and New Zealand, this agent retains full activity and holds promise as an important therapeutic agent for treating serious Gram positive infections, including strains resistant to multiple other drug classes.