Microscan walkaway plus

The clinical specimens were cultured on blood, chocolate, and MacConkey media except for urine processed on cystine lactose electrolyte deficient media (Nosheen et al., 2021 (link)). The identification of the bacteria was accomplished using Gram’s stain, morphology, oxidase, indole, citrate, sugar fermentation, and Microscan WalkAway Plus (Beckman Coulter, USA). A total of 79 K. pneumoniae strains obtained from inpatients and outpatients were isolated from the clinical specimens.

Primary bacterial species identification and antibiotic susceptibility testing were performed with NBPcomb6.23J and Neg MIC6.31J of MicroScan WalkAway Plus (Beckman Coulter, Brea, CA, USA). Strains showing MICs of 4 mg/liter or higher for ceftazidime were judged as potential carbapenemase producers. The MICs were measured using the broth microdilution method in accordance with the CLSI guidelines (M07, 11th edition) (30 ). The following antimicrobial agents were used for antimicrobial susceptibility testing: piperacillin, ceftazidime, and imipenem (Sigma Chemical, St. Louis, MO, USA); ciprofloxacin (LKT Laboratories, St Paul, MN, USA); aztreonam (Tokyo Chemical Industry Co. Ltd., Tokyo, Japan); tazobactam (Toyama Chemical Co., Ltd., Toyama, Japan); meropenem, amikacin, and gentamicin (Wako Pure Chemical Industries, Ltd., Tokyo, Japan); and ertapenem (Merck & Co., Inc., Kenilworth, NJ, USA). The MIC measurement range was 0.125 to 256 mg/liter. E. coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853 were used as quality control strains for antibiotic susceptibility testing. The results were interpreted in accordance with the CLSI guidelines (M100, 31st edition) (31 ).