Figures & data
Figure 1. cDNA amplification of genes from the A1S_0242–0244 operon of A. baumannii ATCC 17978 strain. The intergenic regions from genes A1S_0242–0243 and A1S_0243–0244 are shown in lanes 8 and 9, respectively. The intergenic regions from genes A1S_0241–0242 and A1S_0244–0245 are shown in lanes 7 and 10, respectively (negative controls). Genomic DNA was used as template for positive control (lanes 1 to 5, respectively). Lanes 5 and 11 show the gyrB amplification from DNA and cDNA, respectively (positive controls). Lane 6 shows GeneRuler 1 Kb Plus DNA Ladder (Thermo Fisher Scientific).
Table 1. Interaction of genes A1S_0242, A1S_3850 and A1S_0652 measured by qRT-PCR.
Figure 2. Growth curves of the ATCC 17978 strain and the isogenic mutant derivative strains Δ0242, Δ3850 and Δ0242/Δ3850 in presence and absence of the iron chelator 2,2′-bipyridyl (BIP). Data correspond to the mean of three replicates and bars represent the standard deviations.
Figure 3. Quantification of biofilm formation by the A. baumannii ATCC 17978 strain, the mutant derivative strain Δ0242, the mutant derivative strain Δ3850, the double mutant derivative strain Δ0242/Δ3850, the ATCC 17978 harboring the empty vector pWH1266-Km (ATCC 17978 + pWH1266-Km), the mutant derivative strain harboring the empty vector pWH1266-Km (Δ0242 + pWH1266-Km) and the mutant derivative Δ0242 over-expressing the A1S_0242 gene from the pWH1266-Km plasmid (Δ0242 complemented).
Figure 4. Quantification of bacterial adhesion to A549 cells by the A. baumannii ATCC 17978 strain, the mutant derivative strain Δ0242, the mutant derivative strain Δ3850 and the double mutant strain Δ0242/Δ3850.
Figure 5. Survival of Galleria mellonella larvae (n = 10 per group) after infection with A. baumannii ATCC 17978, Δ0242, Δ3850 and Δ0242/Δ3850 strains. Survival was significantly higher in caterpillars infected with the Δ0242 mutant than those infected with the wild type strain (p < 0.05). No deaths were observed in any of the two control groups (not injected and injected with sterile PBS).
Figure 6. Pneumonia infection in mice. A) Survival of BALB/c (n = 10 per group) mice after pneumonia infection with A. baumannii ATCC 17978 and Δ0242 strains. Survival was significantly higher in mice infected with the Δ0242 mutant (p < 0.01). B) Bacterial load determination in lungs of mice infected with the ATCC 17978 strain and the Δ0242 mutant. Bacterial load (p < 0.01) was significantly lower in mice infected with the Δ0242 mutant.
Table 2. Bacterial strains and plasmids used in this work.
Table 3. Susceptibility to oxidative stress generated by paraquat.
Table 4. Mortality of G. mellonella infected with the A. baumannii ATCC 17978 and its derivative strains using lethal dose 50 (LD50) and lethal dose 100 (LD100).
Table 5. Effect of feoA gene (A1S_0242) inactivation over bacterial load in lungs, blood and mice survival.
