Table 1_Evaluation of eravacycline susceptibility testing by MIC test strip and disk diffusion against broth microdilution in carbapenem-resistant Enterobacterales.doc

However, comparative validation of gradient diffusion (MIC Test Strip, MTS) and disk diffusion (DD) against reference broth microdilution (BMD) specifically in CRE isolates remains limited, particularly under region-specific breakpoint systems.</p>Methods<p>This study evaluated the performance of the MTS and DD against BMD for eravacycline susceptibility testing in 358 CRE clinical isolates (174 carbapenem-resistant Klebsiella pneumoniae, CRKP and 144 carbapenem-resistant Escherichia coli, CREC), using both U.S. Food and Drug Administration (FDA) and Expert Committee of the National Health Commission on Antimicrobial Susceptibility Testing and Standard Research (ChinaCAST) breakpoints.

Categorical agreement (CA), essential agreement (EA), major error (ME), and very major error (VME) were assessed according to CLSI M52 criteria, and Bland-Altman analysis was performed for quantitative agreement between MTS and BMD.</p>Results<p>BMD showed MIC₅₀/MIC₉₀ of 0.25/1 mg/L, with overall susceptibility rate of 81.2% by FDA breakpoints. For MTS, overall CA and EA were 92.8% and 92.5%, but VME was 33.8% under FDA breakpoints, concentrated in CRKP (35.5%).