Department of Biological Science, Center for Applied Biotechnology Studies, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA, USA.
Área Biología Molecular, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
Curr Microbiol. 2021 Nov;78(11):3829-3834. doi: 10.1007/s00284-021-02649-9. Epub 2021 Sep 14.
Acinetobacter baumannii is a multidrug-resistant pathogen that causes numerous infections associated with high mortality rates. Exposure to human body fluids, such as human pleural fluid (HPF) and human serum, modulates gene expression in A. baumannii, leading to changes in its pathogenic behavior. Diverse degrees of effects at the transcriptional level were observed in susceptible and carbapenem-resistant strains. The transcriptional analysis of AB5075, a hyper-virulent and extensively drug-resistant strain showed changes in genes associated with quorum sensing, quorum quenching, fatty acids metabolism, and high-efficient iron uptake systems. In addition, the distinctive role of human serum albumin (HSA) as a critical component of HPF was evidenced. In the present work, we used model strain to analyze more deeply into the contribution of HSA in triggering A. baumannii's response. By qRT-PCR analysis, changes in the expression level of genes associated with quorum sensing, biofilm formation, and phenylacetic acid pathway were observed. Phenotypic approaches confirmed the transcriptional response. HSA, a predominant component of HPF, can modulate the expression and behavior of genes not only in a hyper-virulent and extensively drug-resistant A. baumannii model, but also in other strains with a different degree of susceptibility and pathogenicity.
鲍曼不动杆菌是一种多药耐药病原体，可引起多种与高死亡率相关的感染。人体体液（如人胸腔积液和人血清）的暴露会调节鲍曼不动杆菌中的基因表达，导致其致病行为发生变化。在易感性和碳青霉烯类耐药菌株中，在转录水平上观察到不同程度的影响。对高毒力和广泛耐药的 AB5075 菌株的转录分析显示，与群体感应、群体淬灭、脂肪酸代谢和高效铁摄取系统相关的基因发生了变化。此外，人血清白蛋白（HSA）作为人胸腔积液中关键成分的独特作用也得到了证实。在本工作中，我们使用模型菌株更深入地分析了 HSA 在触发鲍曼不动杆菌反应中的作用。通过 qRT-PCR 分析，观察到与群体感应、生物膜形成和苯乙酸途径相关的基因表达水平的变化。表型方法证实了转录反应。HSA 是 HPF 的主要成分之一，不仅可以调节高毒力和广泛耐药的鲍曼不动杆菌模型中基因的表达和行为，还可以调节其他具有不同易感性和致病性程度的菌株中基因的表达和行为。
