Figure 2

Relative expression of the ompA gene in a clinical isolate of A. baumannii sensitive to polymyxin and after having acquired resistance to this antibiotic. The expression data were normalized by the three most stable genes—fabD, rpoB, and rpoD—individually and with a geometric mean across the three genes (geomean). As a comparison, ompA expression was normalized with 16S, the least stable gene. *p < 0.05, **p ≤ 0.01, ***p ≤ 0.001, and n.s.: not significant (p ≥ 0.05).