Antibiotic susceptibility testing by a standardized single disk method.

In the words of the authors, the paper by A. W. Bauer et al., from the University of Washington in Seattle, on a standardized single-disk method for antibiotic susceptibility testing “. . . consolidate(s) and update(s) previous descriptions of the method and provide(s) a concise outline for its performance and interpretation.” Clinical microbiologists were relieved that finally a disk diffusion method had been standardized, could be used with ease, and provided reliable results as compared with minimum inhibitory concentration tests. The pivotal role of Hans Ericsson’s theoretical and practical studies (H. Ericsson and G. Svartz-Malmberg, Antibiot. Chemother. 6:41–74, 1959), as well as earlier reports by some of the authors of the publications cited, must be mentioned as a matter of fairness. Most of the recommendations given are still valid today even though some of the antimicrobial agents are obsolete, new ones have been added, some zone sizes had to be modified, and new media were designed for Haemophilus influenzae and Neisseria gonorrhoeae. Recommendations of the National Committee for Clinical Laboratory Standards continue to be based on this publication; the “Kirby-Bauer” method is, among the many disk methods used in other countries, still the one that has been researched most thoroughly and updated continuously. ALEXANDER VON GRAEVENITZ