Journal of global antimicrobial resistance | 2021
The in vitro activity of non-antibiotic drugs against S. aureus clinical strains.
Abstract
PURPOSE\nWe hypothesized that one or more of the non-antibiotic candidates selected for this study would demonstrate antibiotic activity against Staphylococcus aureus.\n\n\nMETHODS\nWe determined minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) for non-antibiotic drugs (amlodipine, azelastine, ebselen, and sertraline) against five clinical Staphylococcus aureus isolates and one quality control strain using microplate alamar blue assays. Our research group selected clinical isolates obtained from nasal and wound swab cultures of patients with skin and soft tissue infections (SSTIs) who were seen at primary care clinics in the South Texas Ambulatory Research Network (STARNet).\n\n\nRESULTS\nThree of the non-antibiotic drugs had identical MICs for all isolates: amlodipine (64 µg/ml), azelastine (200 µg/ml), and sertraline (20 µg/ml). MICs for ebselen were 0.25 µg/ml (SA-29213, A1019, and J1019), 0.5 µg/ml (A32 and B60), and 1.0 µg/ml (B72). MBCs for amlodipine, azelastine, and sertraline, were within one dilution of their MICs, indicating bactericidal activity for all test isolates. Ebselen MICs were 1 to 2 dilutions higher in most isolates, also indicating bactericidal activity for all test isolates.\n\n\nCONCLUSION\nIn summary, all four non-antibiotics demonstrated in vitro activity to varying degrees against S. aureus clinical isolates. Ebselen was the most potent of the four non-antibiotics tested.