FIG 1.

mRNA expression of H239_3059 and H239_3062 in different strains. (A and B) The mRNA expression levels of H239_3059 (A) and H239_3062 (B) determined in colistin-resistant and colistin-susceptible clinical isolates were compared. (C) Relative fold expression levels of H239_3059 and H239_3062 in different A4528-derived strains harboring CrrB Q10L, Y31H, W140R, N141I, P151S, and S195N compared with that of the A4528 wild-type strain. The mRNA expression of each strain was calculated by qRT-PCR independently in quadruplicate, and the mRNA expression is indicated as the fold expression relative to that of strain A4528. Statistical analysis of two strains was performed using Student's t test (*, P < 0.05; **, P < 0.01). The error bars represent standard deviations (SD).