Table 2.
List of antimicrobials used in this study
| Antimicrobiala | Abbreviation | Drug class | Drug target(s) | Solvent |
|---|---|---|---|---|
| Amoxicillin | AMX | β-lactam (Penicillin) | Cell wall synthesis | Phosphate bufferb |
| Azithromycin | AZT | Macrolide | Protein synthesis (50S) | ≥95% Ethanol |
| Ceftazidime | CAZ | β-lactam (Cephalosporin) | Cell wall synthesis | Water + 10% (w w-1) Na2CO3 |
| Chloramphenicol | CHL | Amphenicol | Protein synthesis (50S) | ≥95% Ethanol |
| Ciprofloxacin | CIP | Fluoroquinolone | DNA replication, cell division | 0.1 N HCl |
| Colistin | COL | Polymyxin | Cell wall & cell membrane | Water |
| Ertapenem | ETP | β-lactam (Carbapenem) | Cell wall synthesis | Water |
| Fosfomycin | FOS | Phosphonic | Cell wall synthesis (MurA) | Water |
| Gentamicin | GEN | Aminoglycoside | Protein synthesis (30S) | Water |
| Mecillinam | MEC | β-lactam (Penicillin) | Cell wall synthesis (PBP2) | Water |
| Nitrofurantoin | NIT | Nitrofuran | Multiplec | Dimethyl sulfoxide |
| Trimethoprim | TMP | Antifolate | Folate synthesis (FolA) | Dimethyl sulfoxide |
| Sulfamethoxazole | SMX | Antifolate | Folate synthesis (FolP) | Dimethyl sulfoxide |
| TMP + SMX (1:19) | SXT | Antifolate | Folate synthesis (FolA + FolP) | Dimethyl sulfoxide |
| Temocillin | TEM | β-lactam (Penicillin) | Cell wall synthesis | Water |
| Tetracycline | TET | Tetracycline | Protein synthesis (30S) | Water |
| Tigecycline | TGC | Tetracycline | Protein synthesis (30S) | Water |
aWhen available, final antimicrobial concentration was determined using manufacturer-provided or calculated drug potencies, otherwise potency was assumed to be 100%. Aliquots were stored at −20 or −80 °C in single-use vials. All antimicrobials and chemical solvents were obtained from Sigma-Aldrich (St. Louis, MO, USA) with the exception of ciprofloxacin (Biochemika, now Sigma-Aldrich) and temocillin (Negaban®)
b0.1 mol L−1, pH 6.0 phosphate buffer supplemented with 6.5% (v v−1) 1 M NaOH (sodium hydroxide)
cNitrofurantoin is thought to target macromolecules including DNA and ribosomal proteins, affecting multiple cellular processes, including protein, DNA, RNA, and cell wall synthesis