biostudies-literatureSingh MMinistry of Education, Culture, Sports, Science, and Technologye01154-16https://www.ebi.ac.uk/biostudies/studies/S-EPMC5278750biostudies-literatureUnknown61(2)The mechanisms underlying bacterial tolerance to antibiotics are unclear. A possible adaptation strategy was explored by exposure of drug-naive methicillin-susceptible Staphylococcus aureus strain FDA209P to vancomycin in vitro Strains surviving vancomycin treatment (vancomycin survivor strains), which appeared after 96 h of exposure, were slow-growing derivatives of the parent strain. Although the vancomycin MICs for the survivor strains were within the susceptible range, the cytokilling effects of vancomycin at 20-fold the MIC were significantly lower for the survivor strains than for the parent strain. Whole-genome sequencing demonstrated that ileS, encoding isoleucyl-tRNA synthetase (IleRS), was mutated in two of the three vancomycin survivor strains. The IleRS Y723H mutation is locateAntimicrobial agents and chemotherapyIn Vitro Tolerance of Drug-Naive Staphylococcus aureus Strain FDA209P to Vancomycin.PMC5278750S1201013Hishinuma TMorimoto YSingh MSasaki TMatsuo MHiramatsu KfalseIn Vitro Tolerance of Drug-Naive Staphylococcus aureus Strain FDA209P to Vancomycin.The mechanisms underlying bacterial tolerance to antibiotics are unclear. A possible adaptation strategy was explored by exposure of drug-naive methicillin-susceptible Staphylococcus aureus strain FDA209P to vancomycin in vitro Strains surviving vancomycin treatment (vancomycin survivor strains), which appeared after 96 h of exposure, were slow-growing derivatives of the parent strain. Although the vancomycin MICs for the survivor strains were within the susceptible range, the cytokilling effects of vancomycin at 20-fold the MIC were significantly lower for the survivor strains than for the parent strain. Whole-genome sequencing demonstrated that ileS, encoding isoleucyl-tRNA synthetase (IleRS), was mutated in two of the three vancomycin survivor strains. The IleRS Y723H mutation is locate2017-01-01T00:00:00Z2017 Feb2026-05-05T07:40:08.913Z2019-03-27T02:35:14ZS-EPMC52787502785506310.1128/AAC.01154-16