Hüttener Mário, Prieto Alejandro, Espelt Joan, Bernabeu Manuel, Juárez Antonio
Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain.
Institute for Bioengineering of Catalonia, The Barcelona Institute of Science and Technology, Barcelona, Spain.
Front Microbiol. 2018 Apr 10;9:717. doi: 10.3389/fmicb.2018.00717. eCollection 2018.
Virulence expression in the enteroaggregative strain 042 requires the transcriptional activator AggR. We show in this report that, as reported for other virulence factors, the nucleotide second messenger (p)ppGpp is needed for a high expression level of AggR. As expected from these findings, expression of AggR-activated genes such as the AafA pilin subunit is downregulated in the absence of (p)ppGpp. Considering the fact that biofilm formation in strain 042 requires the AafA protein, biofilm development in strain 042 is impaired in derivatives that lack either the AggR protein, the virulence plasmid that encodes AggR (pAA2) or the ability to synthesize (p)ppGpp. These results show a direct correlation between (p)ppGpp, expression of AggR and biofilm development in strain 042.
在肠集聚性菌株042中，毒力表达需要转录激活因子AggR。我们在本报告中表明，正如其他毒力因子的情况一样，核苷酸第二信使（p）ppGpp是AggR高表达水平所必需的。从这些发现可以预期，在缺乏（p）ppGpp的情况下，AggR激活基因（如AafA菌毛亚基）的表达会下调。考虑到菌株042中生物膜形成需要AafA蛋白这一事实，在缺乏AggR蛋白、编码AggR的毒力质粒（pAA2）或合成（p）ppGpp能力的衍生物中，菌株042的生物膜发育会受到损害。这些结果表明（p）ppGpp、AggR的表达与菌株042中生物膜发育之间存在直接关联。
