Evaluation of mice fecal microbiome after immunization with BamA recombinant protein from Acinetobacter baumannii

Previous results demonstrated that the response elicited by immunization with recombinant protein BamA is not completely specific to A. baumannii. Although a broad-spectrum vaccine that protects against various pathogens is an appealing strategy, antibody reactivity against the human microbiota is undesired. To determine if this was indeed the case, we characterized the gut microbiota of animals prior to or after immunization. Therefore, we collected fresh feces of preimmune and immunized C57/Bl6 mice (including animals who received one or two booster doses), extracted fecal DNA, amplified the V3-V4 region of the 16S rRNA gene, and sequenced the amplicons using an Illumina MiSeq system. Finally, Mothur v. 1.44 was used to process the Illumina sequences. In fact, immunization with BamA recombinant protein produced noticeable effects on the gut microbiota. However, the changes elicited were small and non-specific, given that no significant changes in the abundance of Proteobacteria were observed.