Fig. 1: Polyclonal reactivity of Kymouse platform mouse serum raised against OMVs generated from phylogenetically selected A. baumannii.

a Phylogenetic relationship between BAL 084, BAL 191, BAL 215 and BAL 276 and the publicly available CC2, CC1-typed and reference isolates available from culture collections (ATCC and NCTC). The phylogeny was built using whole genome sequence data from the calling of 57844 single nucleotide polymorphisms from 2879 core genes using RAxML (Randomised Axelerated Maximum Likelihood- v8.12.8) using a general time reversible (GTR) model of nucleotide substitution (ASC-GTRGAMMA) and a “Lewis” method of ascertainment bias correction. One hundred bootstrap pseudo-replicate analysis was applied to measure the robustness of the ML phylogeny. The numbers on the tree branches indicate the bootstrap support values while the scale bar reveals the number of nucleotide substitutions per site. The coloured circles at the node tips represent the different capsule types (KLs). b Relative antibody titre measured by indirect ELISA of sera from Kymouse platform mice (n = 5; n defined as serum analysed from a single mouse) immunised with pooled OMVs generated from native, genetically unmodified Acinetobacter baumannii clinical isolates (nOMV) versus sera from 5 non-immunised Kymouse platform mice. c Relative antibody titre similarly measured by indirect ELISA against separate nOMVs generated from phylogenetically related individual isolates not contained in the pool used for immunisation. d Relative titres of human IgG1-4 and IgM subclasses represented in Kymouse platform mouse sera (n = 5; n defined as serum analysed from a single mouse) versus sera from 5 non-immunised Kymouse platform mice against pooled nOMVs used for immunisation. Data for (b, c, d) are presented as mean values ± SEM.