As a nurse at a U.S. military hospital, you treat service members injured in the recent Middle East ...

As a nurse at a U.S. military hospital, you treat service members injured in the recent Middle East conflicts. You notice that wounds infected by Acinetobacter baumannii are not responding to antibiotics. The Centers for Disease Control and Prevention reports that the antibiotic-resistance genes found in A. baumannii are the same as those in Pseudomonas, Salmonella, and Escherichia. Cephalosporin-resistance genes are on the chromosome, tetracycline resistance is encoded by a plasmid, and streptomycin resistance is associated with a transposon.
1.      Can you suggest mechanisms by which Acinetobacter acquired this resistance?