BackgroundAcinetobacter baumanniiis one of the main causes of healthcare-associated infections that threaten public health, and carbapenems, such as meropenem, have been a therapeutic option for these infections. Therapeutic failure is mainly due to the antimicrobial resistance ofA.baumannii, as well as the presence of persister cells. Persisters constitute a fraction of the bacterial population that present a transient phenotype capable of tolerating supra-lethal concentrations of antibiotics. Some proteins have been suggested to be involved in the onset and/or maintenance of this phenotype. Thus, we investigated the mRNA levels of theadeB(AdeABC efflux pump component),ompA, andompW(outer membrane proteins) inA.baumanniicells before and after exposure to meropenem.ResultsWe found a significant increase (p-value< 0.05) in the expression ofompA(> 5.5-fold) andompW(> 10.5-fold) in persisters. However,adeBdid not show significantly different expression levels when comparing treated and untreated cells. Therefore, we suggest that these outer membrane proteins, especially OmpW, could be part of the mechanism ofA.baumanniipersisters to deal with the presence of high doses of meropenem. We also observed in theGalleria mellonellalarvae model that persister cells are more virulent than regular ones, as evidenced by their LD50values.ConclusionsTaken together, these data contribute to the understanding of the phenotypic features ofA.baumanniipersisters and their relation to virulence, as well as highlight OmpW and OmpA as potential targets for drug development againstA.baumanniipersisters.