31.2% (130) were erythromycin non-susceptible/clindamycin intermediate/susceptible (CLSI and EUCAST breakpoints) of which 83.9% (109) were classified as having inducible clindamycin resistance. Multi-resistance was seen in 11.8% of MRSA. This was a significant decrease from the 2015 study (24.3%, p<0.0001). There were no significant differences in interpretation for any drug when CLSI or EUCAST non susceptibility breakpoints were utilised (P>0.05). Table 2: The number and proportion of methicillin-resistant Staphylococcus aureus (MRSA) isolates to penicillin and the non-β-lactam antimicrobials, Australia, 2016 Antimicrobial Tested Breakpoint (mg/L) Non-Susceptible (%) n % Penicillin 500 >0.12* 500 100 Vancomycin 500 >2* 1 0.2 Teicoplanin 500 >8† 0 0 >2‡ 1 0.2 Rifampicin 498 >1† 13 2.6 >0.5‡ 13 2.6 Fusidic Acid 500 >1‡ 16 3.2 Gentamicin 500 >4† 70 14.0 >1‡ 76 15.2 Erythromycin 500 >0.5† 219 43.8 >2‡ 209 41.8 Clindamycin 500 >0.5* 69 13.8 Tetracycline 417 >4† 63 15.1 >2‡ 63 15.1 Co-trimoxazole 500 >2/38† 56 11.2 >4/76‡ 54 10.8 Ciprofloxacin 500 >1* 217 43.5 Nitrofurantoin 488 >32† 1 0.2 >64‡ 0 0 Daptomycin 500 >1* 4 0.8 Linezolid 500 >4* 0 0 *CLSI and EUCAST non-susceptible breakpoint non-susceptible breakpoint †CLSI non-susceptible breakpoint ‡EUCAST
31.2% (130) were erythromycin non-susceptible/clindamycin intermediate/susceptible (CLSI and EUCAST breakpoints) of which 83.9% (109) were classified as having inducible clindamycin resistance. Multi-resistance was seen in 11.8% of MRSA. This was a significant decrease from the 2015 study (24.3%, p<0.0001). There were no significant differences in interpretation for any drug when CLSI or EUCAST non susceptibility breakpoints were utilised (P>0.05). Table 2: The number and proportion of methicillin-resistant Staphylococcus aureus (MRSA) isolates to penicillin and the non-β-lactam antimicrobials, Australia, 2016 Antimicrobial Tested Breakpoint (mg/L) Non-Susceptible (%) n % Penicillin 500 >0.12* 500 100 Vancomycin 500 >2* 1 0.2 Teicoplanin 500 >8† 0 0 >2‡ 1 0.2 Rifampicin 498 >1† 13 2.6 >0.5‡ 13 2.6 Fusidic Acid 500 >1‡ 16 3.2 Gentamicin 500 >4† 70 14.0 >1‡ 76 15.2 Erythromycin 500 >0.5† 219 43.8 >2‡ 209 41.8 Clindamycin 500 >0.5* 69 13.8 Tetracycline 417 >4† 63 15.1 >2‡ 63 15.1 Co-trimoxazole 500 >2/38† 56 11.2 >4/76‡ 54 10.8 Ciprofloxacin 500 >1* 217 43.5 Nitrofurantoin 488 >32† 1 0.2 >64‡ 0 0 Daptomycin 500 >1* 4 0.8 Linezolid 500 >4* 0 0 *CLSI and EUCAST non-susceptible breakpoint †CLSI non-susceptible breakpoint ‡EUCAST non-susceptible breakpoint
AGAR-ASSOP-Annual%20Report%202016.docx