The need to know whether an organism is likely to respond to antimicrobial therapy is as old as
chemotherapy itself, and the background has been covered in this Supplement by Wheat.1
A
number of mechanisms exist by which one may establish the breakpoint between a susceptible
and resistant population of bacteria. In the USA, the Clinical Laboratory Standards Institute
(CLSI), formerly NCCLS, publishes such guidance,2
and has significant influence in many parts of
the world. Other countries, however, have a different philosophy and different methodological
details. Within Europe, there are six active national breakpoint committees, the Comite de
l Antibiogramme de la Societe Francaise de Microbiologie (CA-SFM)3
, France; German Institute
for Standardisation (DIN), Germany; the Norwegian Working Group on Antibiotics (NWGA),
Norway; Swedish Reference Group for Antibiotics (SRGA)4
, Sweden; the Commissie Richtlijenen
Gevoeligneids Depalingen (CRG), The Netherlands; and the BSAC Working Party on
Susceptibility Testing, United Kingdom. The activities of these Committees is now co-ordinated
through the European Committee on Antimicrobial Susceptibility Testing (EUCAST) which is a
standing committee of the European Society for Clinical Microbiology and Infectious Diseases
(ECCMID), and part funded by the European Union (EU)