The Laboratory for Molecular Infection Medicine Sweden (MIMS) and The Department of Molecular Biology, Umeå University, Umeå, Sweden.
Institute of Biomedical and Allied Health Sciences, University of Health Sciences, Lahore, Pakistan.
PLoS One. 2019 Jan 4;14(1):e0210082. doi: 10.1371/journal.pone.0210082. eCollection 2019.
Reversible switching between opaque and translucent colony formation is a novel feature of Acinetobacter baumannii that has been associated with variations in the cell morphology, surface motility, biofilm formation, antibiotic resistance and virulence. Here, we assessed a number of phenotypic alterations related to colony switching in A. baumannii clinical isolates belonging to different multi-locus sequence types. Our findings demonstrated that these phenotypic alterations were mostly strain-specific. In general, the translucent subpopulations of A. baumannii produced more dense biofilms, were more piliated, and released larger amounts of outer membrane vesicles (OMVs). In addition, the translucent subpopulations caused reduced fertility of Caenorhabditis elegans. When assessed for effects on the immune response in RAW 264.7 macrophages, the OMVs isolated from opaque subpopulations of A. baumannii appeared to be more immunogenic than the OMVs from the translucent form. However, also the OMVs from the translucent subpopulations had the potential to evoke an immune response. Therefore, we suggest that OMVs may be considered for development of new immunotherapeutic treatments against A. baumannii infections.
不透光和半透明集落形成之间的可逆转换是鲍曼不动杆菌的一个新特征，与细胞形态、表面运动性、生物膜形成、抗生素耐药性和毒力的变化有关。在这里，我们评估了与不同多位点序列型的鲍曼不动杆菌临床分离株中集落转换相关的一些表型改变。我们的研究结果表明，这些表型改变大多是菌株特异性的。一般来说，鲍曼不动杆菌的半透明亚群产生更密集的生物膜，有更多的菌毛，并且释放更多的外膜囊泡（OMVs）。此外，半透明亚群导致秀丽隐杆线虫的繁殖力降低。在评估对 RAW 264.7 巨噬细胞免疫反应的影响时，从鲍曼不动杆菌不透光亚群分离的 OMVs 似乎比透明形式的 OMVs 更具有免疫原性。然而，透明亚群的 OMVs 也有可能引发免疫反应。因此，我们建议将 OMVs 考虑用于开发针对鲍曼不动杆菌感染的新免疫治疗方法。
