Expert rules
EUCAST expert rules are a tabulated collection of expert knowledge on intrinsic resistances, exceptional resistance phenotypes and interpretive rules that may be applied to antimicrobial susceptibility testing in order to reduce errors and make appropriate recommendations for reporting particular resistances.
Warning! On the 27th of April 2010 EUCAST published new breakpoints for 3rd and 4th gen cephalosporins and aztreonam (see breakpoint tables). A comment was added to breakpoints tables - [Cephalosporin] breakpoints for Enterobacteriaceae will detect clinically important resistance mechanisms (including ESBL). Some strains that produce beta-lactamases are susceptible or intermediate to 3rd or 4th generation cephalosporins with these breakpoints and should be reported as found, i.e. the presence or absence of an ESBL does not in itself influence the categorization of susceptibility. In many areas, ESBL detection and characterization is recommended or mandatory for infection control purposes.
The EUCAST expert rules are currently being revised to mirror these changes. Until the new version is released, there is a disconnect between the new breakpoints and comments and the current Expert Rules version (below).
