Antisera from immunized mice showed remarkable opsonophagocytic killing of clonally distinct clinical isolates.

<p>(A) The antisera from the vaccinated mice presented distinct opsonophagocytic activity in a dose-dependent manner against the homolog strain. Control 1 is a naive serum and control 2 is an irrelevant antigen GFP-immunized serum with Alum as the adjuvant. (B) The complement components were also involved in the antibody-mediated opsonic phagocytosis. The sera were subjected to no heat or heat treatment at 56°C for 30 min to inactivate the complement components. (C) SDS-PAGE and Western blot assays showed similar patterns for 7 clonally distinct clinical isolates of <i>A. baumannii</i>. The antisera collected from the vaccinated mice were pooled and used in the western blot assay. The images are representative of all the experimental replicates. (D) The antisera from the vaccinated mice remarkably reduced the survival of six of the seven clinical isolates. The mouse macrophage RAW264.7 cell line was used for the opsonophagocytic assay. The results presented here are from one of three separate repeated experiments that showed highly similar results.