Acinetobacter baumannii is an important nosocomial pathogen. BamA is a protein that belongs to a complex responsible for organizing the proteins on the bacterial outer membrane. In this work, we aimed to evaluate murine immune responses to BamA recombinant protein (rAbBamA) from A. baumannii in an animal model of infection, and to assess cross-reactivity of this target for the development of anti-A. baumannii vaccines or diagnostics. Immunization of mice with rAbBamA elicited high antibody titers and antibody recognition of native A. baumannii BamA. Immunofluorescence also detected binding to the bacterial surface. After challenge, immunized mice demonstrated a 40% survival increase and better bacterial clearance in kidneys. Immunoblot of anti-rAbBamA against other medically relevant bacteria showed binding to proteins of approximately 35 kDa in Klebsiella pneumoniae and Escherichia coli lysates, primarily identified as OmpA and OmpC, respectively. Altogether, our data show that anti-rAbBamA antibodies provide a protective response against A. baumannii infection in mice. However, the response elicited by immunization with rAbBamA 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. In fact, immunization with rAbBamA 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. Overall, rAbBamA is a promising target, but specificity must be considered in the development of immunological tools against A. baumannii.

鲍曼不动杆菌是一种重要的院内病原体。BamA 是一种蛋白质，属于负责组织细菌外膜上蛋白质的复合物。在这项工作中，我们旨在评估鼠在感染动物模型中对鲍曼不动杆菌BamA 重组蛋白 (rAbBamA) 的免疫反应，并评估该靶标的交叉反应性，以开发抗鲍曼不动杆菌疫苗或诊断方法. 用 rAbBamA 对小鼠进行免疫接种引发了高抗体滴度和天然鲍曼不动杆菌的抗体识别巴马。免疫荧光还检测到与细菌表面的结合。攻击后，免疫小鼠表现出 40% 的存活率增加和更好的肾脏细菌清除率。针对其他医学相关细菌的抗 rAbBamA 的免疫印迹显示与肺炎克雷伯菌和大肠杆菌裂解物中约 35 kDa 的蛋白质结合，主要分别鉴定为 OmpA 和 OmpC。总而言之，我们的数据显示抗 rAbBamA 抗体对小鼠中的鲍曼不动杆菌感染提供保护性反应。然而，用 rAbBamA 免疫引起的反应并不完全特定于鲍曼不动杆菌. 尽管可以预防各种病原体的广谱疫苗是一种吸引人的策略，但抗体对人类微生物群的反应性是不受欢迎的。事实上，rAbBamA 免疫对肠道微生物群产生了显着影响。然而，由于没有观察到变形杆菌丰度的显着变化，因此引起的变化很小且非特异性。总的来说，rAbBamA 是一个很有前途的目标，但在开发针对鲍曼不动杆菌的免疫工具时必须考虑特异性。