Amoxicillin amx

S. aureus NCTC 8325-4 was grown in tryptic soy broth (TSB; BD, NJ, USA) at 37°C with shaking (120 rpm). Amoxicillin (AMX; Sigma-Aldrich, MO, USA), vancomycin (VAN; Sigma-Aldrich, MO, USA), gentamycin (GEN; Sigma-Aldrich, MO, USA), chloramphenicol (CHL; TCI, Tokyo, Japan), tetracycline (TET; Sigma-Aldrich, MO, USA), ciprofloxacin (CIP; Sigma-Aldrich, MO, USA), norfloxacin (NOR; Sigma-Aldrich, MO, USA), and rifampicin (RIF; TCI, Tokyo, Japan) were used as the antibiotics in this study. S. aureus was treated with these antibiotics at MICs. The modes of action of these antibiotics include inhibition of cell wall synthesis, protein synthesis, and DNA gyrase or RNA synthesis inhibition. The detailed information of the antibiotics and their MICs are summarized in Table 1. Optical density (OD) measurements of bacterial cultures were performed in a SPARK 10M microplate reader (TECAN, Männedorf, Switzerland) in a 96-well plate (SPL, Seoul, South Korea), with 200 μL per well. Absorbance was measured at a wavelength of 600 nm and the average value was obtained for triplicate measurements. I sampled the bacterial cultures at 6, 12, and 24 h for measuring single-cell phenotypes using Raman spectroscopy and FCM.

The British Society for Antimicrobial Chemotherapy (BSAC) method for antibiotic susceptibility testing was used to prepare standardised inoculum (Andrews 2001 (link), 2002 ) and for breakpoint values (i.e. antimicrobial threshold concentrations that define resistance/susceptibility). Antimicrobial susceptibility profiles of E. coli clinical isolates were obtained for amoxicillin (AMX) (Sigma), cefotaxime (CTX) (Sigma), chloramphenicol (CAP) (ThermoFisher), ciprofloxacin (CIP) (Fluka), meropenem (MEM) (Sigma), nitrofurantoin (NIT) (Sigma), and trimethoprim (TMP) (Sigma) using the disc diffusion method. Due to poor agar diffusion, the susceptibility of the clinical isolates to polymyxin E (PME) (Sigma) was determined using the minimum inhibitory concentration (MIC) method.