Omp33 detection. (a) 2-DE gels showing A. baumannii proteins from the wild-type strain (ATCC 17978), Δomp33::Km mutant, and Δomp33::Km mutant complemented with pET-RA-OMP33 plasmid (+33). The black circles indicate the Omp33 protein. (b) Western blot analysis showing the detection of the Omp33 protein in the protein extracts obtained from the wild-type and the pETRA-OMP33- complemented mutant strains. (+33): Strains complemented with the pETRA-OMP33 plasmid. C-: Δomp33::Km mutant containing the pET-RA vector (without the omp33 gene) as a negative control. The last lane (C+) indicates detection of the purified Omp33 protein used as a positive control. (c) Reversible staining of the membrane containing the transferred protein extracts from the indicated strains showing similar amounts of the majority protein (43 kDa) prior to Western blot analysis.