Acinetobacter baumannii ATCC 17978 lon suppressor

Acinetobacter baumannii is a leading cause of hospital-acquired infections, where outbreaks are driven by its ability to persist on surfaces in a desiccated state. We have shown that disruption of Lon protease enhances desiccation tolerance in this organism. In the course of culturing the lon mutant, we isolated a suppressor strain with decreased tolerance to desiccation and oxidative stress. Whole genome sequencing of the suppressor revealed an A43E substitution in the receiver domain of BfmR, the response regulator of the BfmRS two-component system. Further characterization of this mutant (lon-supp) revealed that that BfmR-dependent activation of certain transcriptional targets is enhanced in the absence of Lon.