Antimicrobial Effect of 2-Phenylethynyl-ButvItellurium in Escherichia coli ana its Association with Oxidative Stress

作者：Pinheiro Franciane Cabral; Bortolotto Vandreza Cardoso; Araujo Stifani Machado; Poetine Marcia Rosula; Sehn Carla Pohl; Neto Jose S. S.; Zeni Gilson; Prigol Marina^*

来源：Journal of Microbiology and Biotechnology, 2018, 28(7): 1209-1216.

DOI：10.4014/jmb.1802.12074

• Antibacterial
• tellurium
• oxidative stress
• pro-oxidant activity
• thiol groups

This study aimed to evaluate the antimicrobial activity of 2-phenylethynyl-butyltellurium (PEBT) in Escherichia coli and the relation to its pro-oxidant effect. For this, we carried out the disk diffusion test, minimum inhibitory concentration (MIC) assay, and survival curve analysis. We also measured the level of extracellular reactive oxygen species (ROS), activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), and level of nonprotein thiols (NPSH). PEBT at 1.28 and 0.128 mg/disk exhibited antimicrobial capability in the disk diffusion test, with an MIC value of 1.92 mg/ml, whereas PEBT at 0.96, 1.92, and 3.84 mg/ml inhibited bacterial growth after a 9-h exposure. PEBT at 3.84, 1.92, and 0.96 mg/ml increased extracellular ROS production, decreased the intracellular NPSH level, and reduced the SOD and CAT activities. Glutathione or ascorbic acid in the medium protected the bacterial cells from the antimicrobial effect of PEBT. In conclusion, PEBT exhibited antimicrobial activity against E. coli, involving the generation of ROS, oxidation of NPSH, and reduction of the antioxidant defenses in the bacterial cells.

• 出版日期2018-7