2.2. Kirby–Bauer Disc Diffusion Assay

Bacterial cell suspensions in saline (0.9%) were normalized at 0.5 McFarland standard and swabbed onto Mueller Hinton (MH) (Frilabo, Maia, Portugal) agar plates. Disks containing amikacin (AK, 30 μg), cefepime (FEP, 30 μg), ceftazidime (CAZ, 30 μg), ciprofloxacin (CIP, 5 μg), doripenem (DOR, 10 μg), gentamicin (CN, 10 μg), imipenem (IMI, 10 μg), meropenem (MEM, 10 μg), piperacillin (PRL, 30 μg), ticarcillin–clavulanic acid (TTC, 85 μg), and tobramycin (TOB, 10 μg) were placed on the surface of inoculated plates, and diameters of growth inhibition zones were measured after 24 h of incubation at 37 °C. These antibiotics and their concentrations followed the EUCAST 2022 standards [11], except for the antibiotic ceftazidime, which had CLSI 2021 as a reference [12].