Prevention of nosocomial Acinetobacter baumannii infections with a conserved immunogenic fimbrial protein

다국어 초록 (Multilingual Abstract)

Acinetobacter baumannii, one of the most life‐threatening nosocomial drug‐resistant pathogens, imposes high morbidity and mortality rates, thus highlighting immunization‐based treatments or prevention measures. The selection of appropriate antigens can elicit protective immunity. The gene encoding a fimbrial protein introduced via reverse vaccinology was cloned, expressed and evaluated for immunogenicity in a murine model. Mice immunized with the recombinant protein were challenged with A. baumannii ATCC 19606. Adherence to A549 cell line of specific anti‐sera treated A. baumannii was also assessed. Passive immunity was evaluated in a murine pneumonia model. Indirect ELISA showed a high specific antibody titre. Adherence of A. baumannii to A549 cell line decreased by 40% after incubation with 1:250 dilution of specific anti‐sera. All the actively immunized mice survived. Bacterial load in the spleen and liver of the immunized mice was 3‐fold lower than those of the control. The number of bacteria in the lungs of passively immunized mice was about 6‐fold lower than the control mice. The fimbrial protein could be considered as a promising protective immunogen against A. baumannii.