The emergence of antibiotic-resistantAcinetobacter baumanniistrains with limited treatment options has become a significant global health concern. Efforts to develop vaccines against the bacteria have centred on several potential protein targets, including the TonB-dependent receptors (TBDRs). In the present study, TBDRs fromA. baumanniiwere displayed on the surface ofBacillus subtilisspores. The immunogenicity of the recombinant spores was evaluated in orally vaccinated mice. None of the immunized mice demonstrated signs of illness and were observed to be healthy throughout the study. Sera and the intestinal secretions from the recombinant spores-treated mice demonstrated mucosal and humoral antibody responses to the vaccine antigen. In addition, bactericidal activities of the sera againstA. baumanniiclinical isolates were demonstrated. These observations suggest that theB. subtilisspore-displayed TBDRs should be further explored as much-needed potential oral vaccine candidates againstA. baumannii.