Amoxicillin clavulanic acid

Genotypic and phenotypic resistance profiles of isolates were determined using a PCR approach (ARGs and integrases molecular detection) and the Kirby and Bauer method (Bauer et al., 1966 (link)), respectively. The PCR technique was applied to identify the presence of genes encoding β-lactamases (bla_TEM, bla_VIM, bla_IMP, bla_CTX, bla_SHV, and bla_KPC) as previously described by Alves et al. (2014) (link) (Supplementary Table S2). To determine susceptibility profiles, 16 antibiotics were tested by the Kirby and Bauer method on Mueller-Hinton agar medium (Kasvi) in duplicate. The isolates were incubated for 16–24 h at 37°C. The antibiotics used were amoxicillin (10 μg), amoxicillin/clavulanic acid (20 μg/10 μg), ampicillin (10 μg), aztreonam (30 μg), cefepime (30 μg), ceftazidime (30 μg), cefotaxime (30 μg), cephalothin (30 μg), ciprofloxacin (5 μg), chloramphenicol (30 μg), gentamicin (10 μg), imipenem (10 μg), kanamycin (30 μg), nalidixic acid (30 μg), sulfamethoxazole/trimethoprim (25 μg) and tetracycline (30 μg) (Laborclin, Brazil). The strain Escherichia coli ATCC 25922 was used as a control. The mean and standard deviation of inhibition halo values of duplicate were compared to those standardized by the Clinical and Laboratory Standards Institute (CLSI) to classify the strains as susceptible, intermediate or resistant (CLSI, 2017 ).