Hokkaido Institute of Public Health, Kita-19, Nishi-12, Kita-ku, Sapporo, 060-0819, Japan.
Regenerative Medicine Laboratory, Nozaki Tokushukai Hospital Research Institute, 2-10-50 Tanigawa, Daito, 574-0074, Japan.
Commun Biol. 2020 Feb 28;3(1):87. doi: 10.1038/s42003-020-0816-5.
Bacteria use flagella as propellers to move to favorable environments. Escherichia albertii, a growing cause of foodborne illness and diarrhea, is reportedly non-motile and lacks flagella on its surface. Here, we report that 27 out of 59 E. albertii strains, collected mainly from humans and birds, showed swimming motility when cultured at low osmotic pressure. The biosynthesis of flagella in E. albertii cells was induced under ambient temperature and hypoosmotic pressure: conditions which resemble aquatic environments. Flagellar induction increased E. albertii survival in the intestinal epithelial cell culture containing gentamicin. Although genes involved in chemotaxis are not present in the E. albertii genome, the addition of glutamic acid, an amino acid known to regulate the internal cell osmolarity, augmented the proportion of swimming cells by 35-fold. These results suggest that flagellar biosynthesis and motility in E. albertii cells are controlled by their internal and external osmolarity.
细菌利用鞭毛作为推进器移动到有利的环境中。据报道，埃希氏菌属（Escherichia albertii）是食源性疾病和腹泻的一个日益增长的原因，它没有运动能力，表面也没有鞭毛。在这里，我们报告称，从人和鸟类中收集的 59 株埃希氏菌属（Escherichia albertii）菌株中的 27 株，在低渗透压下培养时表现出游泳运动性。在环境温度和低渗透压下诱导埃希氏菌属（Escherichia albertii）细胞中鞭毛的生物合成：这些条件类似于水生环境。鞭毛的诱导增加了埃希氏菌属（Escherichia albertii）在含有庆大霉素的肠上皮细胞培养物中的存活能力。尽管趋化性相关基因不在埃希氏菌属（Escherichia albertii）基因组中，但添加已知调节细胞内渗透压的氨基酸谷氨酸可使游动细胞的比例增加 35 倍。这些结果表明，埃希氏菌属（Escherichia albertii）细胞中鞭毛的生物合成和运动性受到其内外渗透压的控制。
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