Fig. 2From: Multiple heteroresistance to tigecycline and colistin in Acinetobacter baumannii isolates and its implications for combined antibiotic treatmentRelative mRNA expression levels of pmrB gene in both the parental isolates and their colistin-resistant subpopulations (COL-RP). Expression was measured as a relative quantity by quantitative real-time polymerase chain reaction (qRT-PCR) using reference gene rpoB. *p < 0.05; **p < 0.01; ***p < 0.001Back to article page