A series of vectors for inducible gene expression in multidrug-resistant <i>Acinetobacter baumannii</i>

Clinical isolates of bacterial pathogens often harbor resistance to multiple antibiotics, with <i>Acinetobacter baumannii</i> being a prime example. The drug-resistance phenotypes associated with these pathogens represent a significant hurdle to researchers who wish to study modern isolates due to the limited availability of plasmid tools. Here, we present a series of freely replicating and Tn7-insertion vectors that rely on selectable markers to less frequently encountered antibiotics, apramycin, and hygromycin. We demonstrate the utility of these plasmid tools through a variety of experiments looking at a multidrug-resistant strain of <i>A. baumannii</i>, strain AB5075. Strain AB5075 is an established model strain for present-day <i>A. baumannii</i>, due in part to its genetic tractability and because it is a representative isolate of the globally disseminated multidrug-resistant clade of <i>A. baumannii</i>, global clone 1. In addition to the drug-selection markers facilitating use in strains resistant to more commonly used antibiotics, the vectors allow for controllable expression driven by several regulatory systems, including isopropyl β-D-1-thiogalactopyranoside (IPTG), arabinose, anhydrotetracycline, and toluic acid.