The Clinical and Laboratory Standards Institute (CLSI) has released a new edition of its document M100-S24, Performance Standards for Antimicrobial Susceptibility Testing; Twenty-Fourth Informational Supplement. This document provides the revised breakpoints, new recommendations, and reporting changes to incorporate into routine practice to improve detection and reporting of antimicrobial resistance. M100-S24 provides updated tables for the CLSI antimicrobial susceptibility testing standards M02-A11, M07-A9, and M11-A8.
M100-S24 includes revised cefepime disk diffusion and minimal inhibitory concentration (MIC) interpretive criteria along with dosage regimens for using susceptible-dose dependent (SDD) interpretive criteria. The document provides revised doripenem, imipenem, and meropenem disk diffusion and MIC interpretive criteria with dosage regimens on which the breakpoints are based. This edition also includes new cefazolin interpretive criteria and recommendations for use as a surrogate test for uncomplicated UTIs to predict results for oral cephalosporins.
Additionally, M100-S24 includes a definition of susceptible-dose dependent (SDD) with educational information explaining the introduction of SDD interpretive criteria; an example and explanation for antimicrobial agents having only susceptible interpretive criteria; information for reporting first- and second-generation cephalosporins and cephamycins for Salmonella spp. and Shigella spp.; and updated recommendations for the placement of disks on a 100-mm plate. Quality control ranges added and/or revised for M100-S24 include aztreonam-avibactam, biapenem, ceftolozane-tazobactam, eravacycline, surotomycin, and telavancin. View sample pages of M100-S24.
