antimicrobial resistance testing reference standard British Society for Antimicrobial Chemotherapy (BSAC) BSAC BSAC is a British inter-professional organisation involved in antibiotic education, research and leadership. Baquero F. found that the BSAC system recommends lower breakpoints than the consensus standard of all systems for antimicrobial susceptibility testing used in Europe (BSAC, DIN, SFM, SIR, NCCLS and WRG).