FIG 3.

Genes encoding outer membrane integrity and PG maintenance contribute to meropenem tolerance in A. baumannii. (A) Tn-seq analysis of genes required for meropenem tolerance at 12 h. (B) Survival in isogenic mutants was calculated as CFU per milliliter over 24 h during meropenem treatment. Data were collected from two experiments in triplicate. Error bars represent the averages from 3 technical replicates ± SD. (C) Permeability assays using ethidium bromide (EtBr) over 0.5 h. A.U., arbitrary units. Lines depict the means from three technical replicates. (D) MICs of wild-type and isogenic A. baumannii mutant strains. (E) Relative quantification of protein (left) and Kdo (right) concentrations of outer membrane vesicles (OMVs) in wild-type (WT) and mutant strains. Each experiment was independently replicated three times, and one representative data set is reported. Error bars indicate SD from the means. An asterisk indicates significant differences relative to the WT strain (P < 0.05).