RT-PCR and Statistical Analyses of adeABC Expression in Clinical Isolates of Acinetobacter calcoaceticus-Acinetobacter baumannii Complex

The relationship between expression of adeABC and minimal inhibitory concentration (MIC) of tigecycline was investigated by RT-PCR and statistical analyses in a population of 106 clinical isolates (MIC range, 0.0313-16 mu g/ml) of Acinetobacter calcoaceticus-Acinetobacter baumannii complex. There was a statistically significant linear relationship (p < 0.0001) between log-transformed expression values and log-transformed MIC values, indicating that overexpression of AdeABC efflux pump is a prevalent mechanism for decreased susceptibility to tigecycline in A. calcoaceticus-A. baumannii complex.