Investigation of the usefulness of Antimicrobial susceptibility testing for dry plate “DP1R” and report on Antimicrobial susceptibility survey using clinical isolates

Abstract

Antimicrobial susceptibility testing is an important test for determining appropriate antimicrobial therapy. This study, based on the Clinical Laboratory Standards Institute (CLSI), measures the antimicrobial susceptibility of various bacterial species including Corynebacterium, Nocardia, Rapidly Growing Mycobacteria (RGM), and sophisticated anaerobes . We fabricated a custom panel dry plate DP1R (Eiken Chemical Co., Ltd.) which allows concentration measurement, and conducted performance evaluations in collaboration with other institutions. The ATCC strain was used as the evaluation method, and a total of 10 measurements, 5 simultaneous measurements over 5 days, were conducted at 7 facilities to investigate the convergence of MIC values. In addition, 38 Corynebacterium isolates, 34 Nocardia isolates, 67 RGM isolates, and 33 anaerobic isolates were tested for MIC values using clinical isolates. As a result, the DP1R tested this time was considered to be within the acceptable range. Simultaneous reproducibility and inter-day reproducibility across multiple facilities are also good, and it can be seen that the plate performance is sufficient for use. It is also useful from an accuracy assurance standpoint because it can test multiple bacterial species using a CLSI-compliant method. The results of antimicrobial susceptibility testing using a new testing method with DP1R are expected to greatly contribute greatly to the selection of appropriate antimicrobial a treatment.