Conjunction of Modular Beta-lactamase Encoding Gene Amplification with Porin Loss Drives Carbapenem Resistance in ESBL Positive Enterobacteriaceae from Patients with Recurrent Bacteremia

Investigate ESBL-positive Enterobacteriaceae that develop carbapenem resistance through non-carbapenemase-producing mechanisms in cancer patients with recurrent bacteremia. The objective of this study is to characterize clonal, serial isolates that develop carbapenem resistance via non-carbapenemase mechanisms. Our hypothesis is that a proportion of recurrent bacteremia cases due to persistent carriage of the same clonal, re-infecting strains have the ability to develop resistance to carbapenems independent of carbapenemase acquisition within our cancer population. We believe this is occurring through a mobile genetic element amplification mechanism with concomitant outer membrane porin disruption.