Transcription profiling of Pseudomonas aeruginosa representational genomic libraries to identify aminoglycoside resistance genes

For this study, we created three highly representational different sized genomic libraries of P. aeruginosa PAO1 within the vector pBTB-1. Vector pBTB-1 is a low copy number broad host range plasmid containing a ß-lactamase resistance marker, a pBAD promoter upstream of the cloning site, as well as transcriptional terminators flanking the cloning site to aid in insert stability. These libraries were transformed into the recombination-deficient P. aeruginosa PAO1 mutant, PAO2003, pooled, and parallel selections performed to identify via traditional sequencing or SCALEs the genomic regions capable of conferring increased tolerance to amikacin, gentamicin, or tobramycin. These antibiotics are all structurally related but have differing substitution patterns on their aminoglycoside backbones. These differences in structure and substitution patterns impact the activity of each antibiotic. We chose to study three different aminoglycosides in attempts to identify genomic regions capable of conferring resistance to not only a specific aminoglycoside, but also to the more general class of aminoglycosides.

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