“For both the type A (i.e., possessing transferable resistance to teicoplanin and vancomycin) and the type … (i.e., possessing teicoplanin susceptibility and nontransferable vancomycin resistance) resistant strains, vancomycin MICs in the presence of glycine were substantially lower than those … unsupplemented broth (range of MIC decrease, 8- … 128-fold).”