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bioRxiv · 10.1101/615336

Resistance to aztreonam, in combination with a bicyclic boronate β-lactamase inhibitor in Escherichia coli identified following mixed culture selection

Cheung, C. H. P.·Findlay, J.·Heesom, K. J.·Avison, M.
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Abstract

Using mixed culture selection, we show how reduced envelope permeability, reduced target-site affinity, and increased {beta}-lactamase production layer to confer aztreonam/{beta}-lactamase inhibitor resistance in Escherichia coli. We report a clinical isolate producing CTX-M-15 and CMY-4, lacking OmpF, and carrying a PBP3 mutation. It is resistant to aztreonam plus the inhibitors avibactam, relebactam and vaborbactam. Mobilisation of blaSHV-12 into this isolate generated a derivative additionally resistant to aztreonam plus the bicyclic boronate inhibitors 2 and taniborbactam.

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Cheung, C. H. P., Findlay, J., Heesom, K. J., Avison, M.. 2019-04-23. Resistance to aztreonam, in combination with a bicyclic boronate β-lactamase inhibitor in Escherichia coli identified following mixed culture selection. https://doi.org/10.1101/615336

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