In vivo de-amplification of a multi-resistance pseudo-compound transposon in Escherichia coli
This study characterizes the 18-week in vivo evolution of a multi-drug resistant *Escherichia coli* in an infant gut, revealing a unique de-amplification of an IS26-mediated tandem array of antibiotic resistance genes that reduced the gene copy number without compromising bacterial fitness or altering susceptibility to piperacillin-tazobactam.