Phenotype evaluation rawdata of Acinetobacter baumannii harboring chromosomal parallel mutations or an evolved plasmid

OXA-23 is the predominant carbapenemase in carbapenem-resistant Acinetobacter baumannnii. The co-evolutionary dynamics of A. baumannii and OXA-23-encoding plasmids are poorly understood. Here, we transformed A. baumannnii ATCC 17978 with pAZJ221, a blaOXA-23-containing plasmid from a clinical A. baumannnii isolate A221, and subjected the transformant to experimental evolution in the presence of a sub-inhibitory concentration of imipenem for nearly 400 generations. We used population sequencing to track genetic changes at six time-points and evaluated phenotypic changes. Increased fitness of evolving populations, temporary duplication of blaOXA-23 in pAZJ221, interfering allele dynamics, and chromosomal locus-level parallelism were observed. To characterize genotype-to-phenotype associations, we focused on six mutations in parallel targets predicted to affect small RNAs and a cyclic dimeric (3’→5’) GMP-metabolizing protein. Six isogenic mutants with or without pAZJ221 were engineered to ...