Investigation of the human pathogen Acinetobacter baumannii under iron limiting conditions.
Investigation of the human pathogen Acinetobacter baumannii under iron limiting conditions.
复制标题
DOI：
10.1186/1471-2164-12-126
复制
发表时间：
2011-02-23
期刊：
影响因子：
4.4
通讯作者：
Brown MH
中科院分区：
文献类型：
--
作者：
Eijkelkamp BA;Hassan KA;Paulsen IT;Brown MH
铁获取系统是致病菌重要的毒力因子。为了鉴定鲍曼不动杆菌中的这些系统，使用包含所有带注释的开放阅读框探针的基因组微阵列研究了完全测序的菌株ATCC 17978在铁限制条件下的转录组反应。在低铁条件下，463个基因的转录水平上调2倍以上，其中95个基因的转录水平上调4倍以上。特别重要的是，包括一个新基因簇在内的三个铁载体生物合成基因簇被高度上调。铁摄取调节因子的结合位点位于许多上调基因的启动子区域，表明该调节因子在不动杆菌铁获取反应中起着重要作用。铁限制下的下调幅度较小，只有202个基因的转录变化超过2倍。当铁不容易获得时，与运动有关的各种基因在基因下调中表现突出。运动分析证实，这些转录变化表现在表型水平。通过对10株不动杆菌的比较基因组分析，进一步研究了铁载体生物合成基因簇。这些分析揭示了不同不动杆菌菌株之间铁载体介导的铁获取机制中移动遗传元件的重要作用。在铁限制条件下生长的鲍曼不动杆菌不仅导致许多铁获取相关基因的转录发生重大变化，而且导致参与运动等其他过程的基因的转录发生重大变化。总体而言，本研究表明鲍曼不动杆菌能够很好地适应铁离子利用率有限的环境。
Iron acquisition systems are important virulence factors in pathogenic bacteria. To identify these systems in Acinetobacter baumannii, the transcriptomic response of the completely sequenced strain ATCC 17978 under iron limiting conditions was investigated using a genomic microarray that contained probes for all annotated open reading frames. Under low iron conditions, transcription levels were more than 2-fold up-regulated for 463 genes, including 95 genes that were up-regulated more than 4-fold. Of particular significance, three siderophore biosynthesis gene clusters, including one novel cluster, were highly up-regulated. Binding sites for the ferric uptake regulator were identified in the promoter regions of many up-regulated genes, suggesting a prominent role for this regulator in the Acinetobacter iron acquisition response. Down-regulation under iron limitation was less dramatic as the transcription of only 202 genes varied more than 2-fold. Various genes involved in motility featured prominently amongst the genes down-regulated when iron was less readily available. Motility assays confirmed that these transcriptional changes are manifested at the phenotypic level. The siderophore biosynthesis gene clusters were further investigated by means of comparative genomic analysis of 10 sequenced Acinetobacter isolates. These analyses revealed important roles for mobile genetic elements in shaping the siderophore meditated iron acquisition mechanisms between different Acinetobacter strains. A. baumannii grown under iron limited conditions resulted in major transcriptional changes of not only many iron acquisition related genes, but also genes involved in other processes such as motility. Overall, this study showed that A. baumannii is well adaptable to growth in an environment which has limiting iron availability.
登录
查看更多内容
影响因子：
2.8
作者：
Dorsey, CW;Tolmasky, ME;Actis, LA
通讯作者：
Actis, LA
影响因子：
5.8
作者：
Brazma, A;Vilo, J
通讯作者：
Vilo, J
影响因子：
2.8
作者：
Dorsey, CW;Tomaras, AP;Actis, LA
通讯作者：
Actis, LA
影响因子：
9.4
作者：
Dorsey, CW;Beglin, MS;Actis, LA
通讯作者：
Actis, LA
影响因子：
3.6
作者：
Furrer, JL;Sanders, DN;McIntosh, MA
通讯作者：
McIntosh, MA