Antimicrobial use and resistance in Australia.

• Australia has different patterns of AMR to other countries. There are a number of organisms, mainly gram-positive, of particular concern (Figure 1). Others, mainly gram-negative, show a lower rate of resistance, possibly due to restricted use of some antimicrobials (Table 1). • Resistances and trends of concern include resistance to third-generation cephalosporins and carbapenems in Enterobacteriaceae, decreased susceptibility to ceftriaxone in Neisseria gonorrhoeae, resistance to ciprofloxacin in Shigella species, and resistance to erythromycin in Streptococcus agalactiae. • Vancomycin resistance in Enterococcus faecium causing serious infections is between 45 66%. • Community strains of MRSA now cause a significant proportion of infections in the community and are resulting in hospitalisation, with communityassociated MRSA clones (includes nursing homes) now overtaking hospital-associated clones in hospital onset staphylococcal sepsis. • At present, Australia has low rates of resistance to fluoroquinolones in Escherichia coli compared with other countries, reflecting the restricted use of this antimicrobial class locally. • By contrast, resistance to the β-lactams available in the community, including amoxicillin, amoxicillinclavulanate cefalexin and the third-generation cephalosporins is increasing. • Macrolide, tetracycline and co-trimoxazole resistance in Streptococcus pneumoniae is now 20 30%, limiting second-line treatment options for bacterial lower respiratory tract infections in the community. 1 Senior Medical Advisor, 2 Director, 3 Project Officer, 4 Senior Project Officer