Molecular Mechanisms Involved in the Response to Desiccation Stress and Persistence in Acinetobacter baumannii
Molecular Mechanisms Involved in the Response to Desiccation Stress and Persistence in Acinetobacter baumannii
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DOI：
10.1021/pr400603f
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发表时间：
2014-02-01
影响因子：
4.4
通讯作者：
Bou, German
中科院分区：
文献类型：
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作者：
Gayoso, Carmen M.;Mateos, Jesus;Bou, German
脱水耐受有助于维持医院环境中的细菌种群，并可能部分解释其引起暴发的倾向。使用无标记定量和iTRAQ标记对参与细菌脱水耐受性的蛋白质进行鉴定和相对定量。在干燥条件下，鲍氏不动杆菌临床菌株AbH 12 O-A2的种群在第一周内减少，此后，维持在原始种群的0.5%的稳定种群。使用无标记定量和iTRAQ标记，分别检测到727和765种蛋白质，其中584种通过两种方法。在干燥下过表达的蛋白质包括膜和周质蛋白。与抗菌素耐药性，外排泵和群体淬灭相关的蛋白质在干燥胁迫的样品中过表达。电子显微镜显示干燥和控制细菌之间存在明显的形态差异。我们的结论是A.鲍曼不动杆菌能够通过休眠状态下细胞的存在，通过影响细胞周期控制、DNA卷曲、转录和翻译调节、蛋白质稳定、抗微生物剂抗性和毒素合成的机制，并且包埋在生物膜基质中的少数存活细胞能够在适当的环境条件下恢复生长并恢复原始群体，“爆炸和繁荣”的战略。
Desiccation tolerance contributes to the maintenance of bacterial populations in hospital settings and may partly explain its propensity to cause outbreaks. Identification and relative quantitation of proteins involved in bacterial desiccation tolerance was made using label-free quantitation and iTRAQ labeling. Under desiccating conditions, the population of the Acinetobacter baumannii clinical strain AbH12O-A2 decreased in the first week, and thereafter, a stable population of 0.5% of the original population was maintained. Using label-free quantitation and iTRAQ labeling, 727 and 765 proteins, respectively, were detected; 584 of them by both methods. Proteins overexpressed under desiccation included membrane and periplasmic proteins. Proteins associated with antimicrobial resistance, efflux pumps, and quorum quenching were overexpressed in the samples subjected to desiccation stress. Electron microscopy revealed clear morphological differences between desiccated and control bacteria. We conclude that A. baumannii is able to survive long periods of desiccation through the presence of cells in a dormant state, via mechanisms affecting control of cell cycling, DNA coiling, transcriptional and translational regulation, protein stabilization, antimicrobial resistance, and toxin synthesis, and that a few surviving cells embedded in a biofilm matrix are able to resume growth and restore the original population in appropriate environmental conditions following a "bust-and-boom" strategy.