Imipenem ipm

Antimicrobial susceptibility testing was performed according to Clinical and Laboratory Standards Institute recommendations (M100 document) [16 ]. The diffusion method on Mueller–Hinton agar was used to test susceptibility to different antibiotics, including amoxicillin (AMX) (30 µg), cefipime (FEP) (30 µg), cephalothin (CF) (30 µg), ceftazidime (30 µg), amoxicillin-clavulanic acid (AMC) (30 µg), cefotaxime (CTX) (30 µg), ertapenem (ETP) (10 µg), aztreonam (30µg), meropenem (MEM) (10 µg), and imipenem (IPM) (10 µg) (Oxoid, Basingstoke, UK).
The selected isolates were resistant to ertapenem (≤18 mm), imipenem (≤19 mm), and/or meropenem (≤19 mm). The resistant isolates were confirmed by the Vitek 2 system (Biomérieux, Marcy l’Etoile, France) at MIC values ≥ 2 µg/mL for ETP and ≥4 µg/mL for IPM and MEM.

Minimum inhibitory concentrations (MICs) for A. pittii TCM strain against multiple antibiotics were tested by using disk diffusion and broth microdilution. It interpreted breakpoints for Acinetobacter spp. according to the recommendations from the Clinical and Laboratory Standards Institute (CLSI), 2021 guidelines and European Committee on Antimicrobial Susceptibility Testing (EUCAST), 2021 . Because there is no tigecycline breakpoint for Acinetobacter, MIC was interpreted according to the guidelines of EUCAST for Enterobacterales (with MIC breakpoint value ≤0.5 mg/L denoting susceptibility and >0.5 mg/L denoting resistance). The antibiotic disks used in this study included imipenem (IPM, 10 µg, Oxoid, Cheshire, UK), meropenem (MEM, 10 µg, Oxoid, Cheshire, UK), Amikacin (AMI, 30 µg, Oxoid, Cheshire, UK), and ciprofloxacin (CIP, 5 µg, Oxoid, Cheshire, UK) in a Mueller-Hinton agar (MHA) culture medium (Oxoid, Cheshire, UK). In addition to the antibiotics mentioned above, colistin (COL, Sigma-Aldrich, St. Louis, MO, USA) and tigecycline (TGC, Sigma-Aldrich, St. Louis, MO, USA) were also investigated using broth microdilution. Escherichia coli ATCC 25922 served as the quality control strain.