肺部通常是鲍曼不动杆菌的目标。人肺泡基底上皮细胞系,A549可作为探测病原体-细胞动力学的有价值的体外模型。这项研究检查了两个不动杆菌菌株,ATCC19606和临床分离物58ST,调查他们的坚持,内化,和A549细胞系内的细胞毒性以阐明致病机制。表达抗BamA抗体,纯化,并通过间接ELISA检测。在BALB/c小鼠中评估BamA的毒性。两种鲍曼不动杆菌菌株均用于感染A549细胞以检查细胞侵袭多样性。血清抗性,生物膜的产生和抑制,附着力,内化,在有和没有抗BamA血清的情况下,检测活的和灭活的鲍曼不动杆菌的细胞内增殖。在活鲍曼不动杆菌和抗BamA血清暴露细菌的存在下评估A549细胞活力。对上皮细胞进行细胞骨架抑制剂试验。鲍曼不动杆菌菌株表现出不同的细胞侵袭能力,临床变异表现出最高的侵袭能力。在内化过程中,鲍曼不动杆菌细胞位于液泡内,并使用拉链样侵袭机制向细胞核迁移。宿主细胞内的细菌分裂最终导致细胞死亡。用抗BamA抗体的预处理基本上阻碍了鲍曼不动杆菌在上皮细胞中的粘附和侵袭。显微镜成像验证了A549细胞中鲍曼不动杆菌的细胞内存在,验证他们的入侵潜力和居住权。这些发现证实了鲍曼不动杆菌在上皮细胞中增殖的能力,具有BamA对抗鲍曼不动杆菌-上皮细胞相互作用的关键作用。这项研究增强了我们对鲍曼不动杆菌发病机理的认识,促进开发针对鲍曼不动杆菌感染的有效策略。
The lungs are commonly targeted by Acinetobacter baumannii. The human alveolar basal epithelial cell line,
A549, serves as a valuable in vitro model for probing pathogen-cell dynamics. This study examined two Acinetobacter strains, ATCC 19606 and the clinical isolate 58ST, investigating their adherence, internalization, and cytotoxicity within the
A549 cell line to illuminate pathogenic mechanisms. Anti-BamA antibodies were expressed, purified, and detected via indirect ELISA. The toxicity of BamA was assessed across BALB/c mice. Both A. baumannii strains were used to infect
A549 cells to scrutinize cell invasion diversity. Serum resistance, biofilm creation and inhibition, adhesion, internalization, and intracellular proliferation of live and inactivated A. baumannii were probed with and without anti-BamA sera.
A549 cell viability was evaluated in the presence of live A. baumannii and anti-BamA sera-exposed bacteria. Cytoskeleton inhibitor tests were conducted on epithelial cells. A. baumannii strains displayed differing cell invasion aptitudes, with the clinical variant manifesting the highest invasion capability. During internalization, A. baumannii cells localized within vacuoles and migrated towards the nucleus using a zipper-like invasion mechanism. Bacterial division inside host cells culminated in cell demise. Pre-treatment with anti-BamA antibodies substantially impeded A. baumannii\'s adherence and invasion in epithelial cells. Microscopic imaging validated the intracellular presence of A. baumannii in
A549 cells, verifying their invasive potential and residency. These findings substantiate A. baumannii\'s capacity to proliferate in epithelial cells, with BamA pivotal role against A. baumannii-epithelial cell interplay. This study augments our insight into A. baumannii pathogenesis, facilitating the development of efficacious strategies against A. baumannii infections.