Fig. 1

Pingwei Pill restored the activity of colistin against MCR-1-positive bacteria without affecting bacterial growth. Checkerboard dilution analysis shows the combined effect of Pingwei Pill and colistin against the mcr-1-positive strains K. pneumoniae ZJ02 (A) and Salmonella sp. strain HYM2 (B), E. coli ZJ478 (C) and E. coli DH5α (pUC19-mcr-1) (D). Color darkness or lightness represents the bacterial activity. Data were analyzed 4 times for biologically independent experiments. Growth curve of K. pneumoniae ZJ02 (E), Salmonella sp.strain HYM2 (F), E. coli ZJ478 (G) and E. coli DH5α (pUC19-mcr-1) (H) in the presence of the indicated concentrations of Pingwei Pill. Kill-curve kinetics of K. pneumoniae ZJ02 (I), Salmonella sp. strain HYM2 (J), E. coli ZJ478 (K) and E. coli DH5α (pUC19-mcr-1) (L) with the indicated treatment. Data are presented as the means ± S.D. of three biologically independent experiments