The magnitude of persister levels from ACB planktonic and, particularly, biofilm cultures exposed to meropenem was independent of the antibiotic concentration, dosing regimen and biofilm biomass. These findings, in a context of meropenem failure to treat chronic infections, strengthen the importance of understanding persister behavior.

Aeration may have stimulated bacterial growth, providing more targets for antibiotic action and leading to increased production of reactive oxygen species, which decreased levels of persisters.