Department of Food and Animal Biotechnology, Center for Agricultural Biomaterials, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea.
Int J Med Microbiol. 2012 Nov;302(6):270-5. doi: 10.1016/j.ijmm.2012.06.001. Epub 2012 Jul 5.
Cronobacter sakazakii is a Gram-negative opportunistic pathogen that causes necrotizing enterocolitis, sepsis, and meningitis in premature infants. The genetic basis of C. sakazakii virulence is poorly understood. In this study, the putative LysR-type transcriptional regulator (LTTR) gene (ESA_01081 homolog) was characterized as a possible regulator for C. sakazakii pathogenesis. An in-frame deletion mutant of the ESA_01081 homolog and its cognate complementation strain were constructed and characterized for pathogenesis (adhesion/invasion potentials to human intestinal cells and in vivo rat pup challenge assay), biofilm formation, resistance to oxidative stress and induction of IL-8 secretion. LTTR-deficient C. sakazakii ATCC 29544 exhibits significantly attenuated phenotypes in all the properties tested, except adhesion. Our data strongly suggest that the putative gpESA_01081 homolog, plays an important regulatory role in diverse biological processes including the virulence of C. sakazakii. This is the first report of a functional global regulator in C. sakazakii.
阪崎克罗诺杆菌是一种革兰氏阴性机会致病菌，可导致早产儿坏死性小肠结肠炎、败血症和脑膜炎。阪崎克罗诺杆菌的毒力遗传基础尚未完全清楚。本研究中，假定的 LysR 型转录调节因子（LTTR）基因（ESA_01081 同源物）被鉴定为阪崎克罗诺杆菌发病机制的可能调节剂。构建了 ESA_01081 同源物的无框缺失突变体及其同源互补菌株，并对其进行了发病机制（对人肠细胞的粘附/侵袭潜力和体内大鼠幼仔挑战试验）、生物膜形成、氧化应激抗性和诱导 IL-8 分泌的研究。LTTR 缺陷型阪崎克罗诺杆菌 ATCC 29544 在所有测试的特性中表现出明显减弱的表型，除了粘附。我们的数据强烈表明，假定的 gpESA_01081 同源物在包括阪崎克罗诺杆菌毒力在内的多种生物学过程中发挥重要的调节作用。这是首次在阪崎克罗诺杆菌中报道功能性全局调节因子。
