An evaluation of the modified carbapenem inactivation method (mCIM) in conjunction with EDTA or sodium mercaptoacetate, for detecting metallo β-lactamase production for Aeromonas species harboring bla.

Several Aeromonas species, including Aeromonas hydrophila, have been known to produce CphA, a chromosomal metallo β-lactamase (MBL). We aimed to evaluate the clinical usefulness of modified carbapenem inactivation method (mCIM) in conjunction with EDTA (eCIM) or sodium mercaptoacetate (SMA-mCIM) for MBL-producing Aeromonas species. Fifty-six clinical isolates of Aeromonas species stored at the University of the Ryukyus Hospital were used in this study.

Evaluation of the feasibility of EUCAST RAST using antimicrobial disks available in Japan.

Background: In November 2018, the European Committee for Antimicrobial Susceptibility Testing (EUCAST) established rapid antimicrobial susceptibility testing (RAST), which could be performed directly on positive blood culture samples. Although concentrations of antimicrobial agents in several antimicrobial disks available in Japan are different from those recommended by the EUCAST, the feasibility of EUCAST RAST using antimicrobial disks available in Japan remains to be evaluated.

Methods: Blood culture bottles spiked with 127 clinical isolates (65 Escherichia coli and 62 Klebsiella pneumoniae) were tested by RAST for cefotaxime (CTX), ceftazidime (CAZ), meropenem, and ciprofloxacin using antimicrobial disks available in Japan, and compared with a reference AST method using automated AST instrument (VITEK®2).