University of Kentucky, Department of Biology, USA.
University of Kentucky, Department of Veterinary Science, USA; University of Kentucky, Department of Microbiology, Immunology, and Molecular Genetics, USA; University of Kentucky, Department of Pharmaceutical Sciences, Lexington, KY 40506, USA.
Genomics. 2022 Mar;114(2):110321. doi: 10.1016/j.ygeno.2022.110321. Epub 2022 Feb 24.
Klebsiella (nee Enterobacter) aerogenes is the first human gut commensal bacterium with a documented sensitivity to the pineal/gastrointestinal hormone melatonin. Exogenous melatonin specifically increases the size of macrocolonies on semisolid agar and synchronizes the circadian clock of K. aerogenes in a concentration dependent manner. However, the mechanisms driving these phenomena are unknown. In this study, we applied RNA sequencing to identify melatonin sensitive transcripts during culture maturation. This work demonstrates that the majority of melatonin sensitive genes are growth stage specific. Melatonin exposure induced differential gene expression of 81 transcripts during exponential growth and 30 during early stationary phase. This indole molecule affects genes related to biofilm formation, fimbria biogenesis, transcriptional regulators, carbohydrate transport and metabolism, phosphotransferase systems (PTS), stress response, metal ion binding and transport. Differential expression of biofilm and fimbria-related genes may be responsible for the observed differences in macrocolony area. These data suggest that melatonin enhances Klebsiella aerogenes host colonization.
产酸克雷伯菌（原肠杆菌属）是第一个被记录对松果腺/胃肠激素褪黑素敏感的人类肠道共生菌。外源性褪黑素特异性地增加半固体琼脂上的大菌落大小，并以浓度依赖的方式使产酸克雷伯菌的生物钟同步。然而，驱动这些现象的机制尚不清楚。在这项研究中，我们应用 RNA 测序来鉴定培养成熟过程中对褪黑素敏感的转录本。这项工作表明，大多数对褪黑素敏感的基因是生长阶段特异性的。褪黑素暴露诱导了 81 个转录本在指数生长期间和 30 个在早期静止期的差异表达。这种吲哚分子影响与生物膜形成、菌毛生物发生、转录调节剂、碳水化合物运输和代谢、磷酸转移酶系统（PTS）、应激反应、金属离子结合和运输相关的基因。生物膜和菌毛相关基因的差异表达可能是观察到的大菌落面积差异的原因。这些数据表明，褪黑素增强了产酸克雷伯菌的宿主定植。
