An E. coli and K. pneumoniae phenotype resistant to piperacillin/tazobactam has recently emerged. Here, the authors show that hyperproduction of the β-lactamase driving this resistance occurs due to excision and reinsertion of a translocatable unit containing blaTEM-1B, creating a tandem array.
- Alasdair T. M. Hubbard
- Jenifer Mason
- Thomas Edwards