Niu Hongxia, Li Tuodi, Du Yunjie, Lv Zhuoxuan, Cao Qianqian, Zhang Ying
School of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China.
School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China.
Microorganisms. 2023 Apr 29;11(5):1173. doi: 10.3390/microorganisms11051173.
To verify the roles of GltS, GltP, and GltI in tolerance and pathogenicity, we quantified and compared the relative abundance of , , and in log-phase and stationary-phase and constructed their knockout mutant strains in BW25113 and uropathogenic (UPEC) separately, followed by analysis of their abilities to tolerate antibiotics and stressors, their capacity for adhesion to and invasion of human bladder epithelial cells, and their survival ability in mouse urinary tracts. Our results showed that , , and transcripts were higher in stationary phase than in log-phase incubation. Furthermore, deletion of , , and genes in BW25113 results in decreased tolerance to antibiotics (levofloxacin and ofloxacin) and stressors (acid pH, hyperosmosis, and heat), and loss of , , and in uropathogenic UTI89 caused attenuated adhesion and invasion in human bladder epithelial cells and markedly reduced survival in mice. The results showed the important roles of the glutamate transporter genes , , and in tolerance to antibiotics (levofloxacin and ofloxacin) and stressors (acid pH, hyperosmosis, and heat) in vitro and in pathogenicity in mouse urinary tracts and human bladder epithelial cells, as shown by reduced survival and colonization, which improves our understanding of the molecular mechanisms of bacterial tolerance and pathogenicity.
为了验证谷氨酸转运蛋白S（GltS）、谷氨酸转运蛋白P（GltP）和谷氨酸转运蛋白I（GltI）在耐受性和致病性中的作用，我们对对数期和稳定期大肠杆菌中GltS、GltP和GltI的相对丰度进行了定量和比较，并分别在大肠杆菌BW25113和尿路致病性大肠杆菌（UPEC）中构建了它们的基因敲除突变株，随后分析它们耐受抗生素和应激源的能力、黏附并侵袭人膀胱上皮细胞的能力以及在小鼠尿道中的存活能力。我们的结果表明，GltS、GltP和GltI的转录本在稳定期大肠杆菌中的水平高于对数期培养时。此外，在大肠杆菌BW25113中敲除GltS、GltP和GltI基因会导致其对抗生素（左氧氟沙星和氧氟沙星）和应激源（酸性pH值、高渗和热）的耐受性降低，而在尿路致病性大肠杆菌UTI89中缺失GltS、GltP和GltI会导致其对人膀胱上皮细胞的黏附及侵袭能力减弱，并使其在小鼠体内的存活率显著降低。结果表明，谷氨酸转运蛋白基因GltS、GltP和GltI在体外对抗生素（左氧氟沙星和氧氟沙星）和应激源（酸性pH值、高渗和热）的耐受性以及在小鼠尿道和人膀胱上皮细胞的致病性中发挥重要作用，表现为存活率和定植率降低，这增进了我们对细菌耐受性和致病性分子机制的理解。
