Effects of 462 nm Light-Emitting Diode on the Inactivation of Escherichia coli and a Multidrug-Resistant by Tetracycline Photoreaction

Journal of Clinical Medicine

Chun-Yi Wu¹  Yi-An Hung¹  Chien-Wei Cheng¹  Ji-Yuan Liang¹  Tak-Wah Wong²  Shiuh-Tsuen Huang³  Nan‐Yao Lee⁴  Meei-Ju Yang⁵ 

[1] Department of Biotechnology, Ming-Chuan University, Gui-Shan 33343, Taiwan;Department of Dermatology, National Cheng Kung University Hospital, Department of Biochemistry and Molecular Biology, College of Medicine, Center of Applied Nanomedicine, National Cheng Kung University, Tainan 70101, Taiwan;Department of Science Education and Application, National Taichung University of Education, Taichung 40306, Taiwan;Division of Infection, Department of Internal Medicine, National Cheng Kung University Hospital, Department of Medicine, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan;Tea Research and Extension Station, Taoyuan 32654, Taiwan;

关键词: blue light;    inactivation;    MDR E. coli;    skin and soft tissue infections (SSTIs);    tetracycline;   

DOI  :  10.3390/jcm7090278

来源: DOAJ

【 摘 要 】

The adaptability of bacterial resistance to antibiotics contributes to its high efficiency during evolution. Tetracycline (TC) is a broad-spectrum antimicrobial agent. Chromatographic analyses and mass spectrometry were used to study the effects of the light illumination of a 462 nm light-emitting diode (LED) on the conformational changes of TC in a phosphate buffer solution (PBS, pH 7.8). Especially, the inactivation of superoxide anion radicals (O2•−) and Escherichia coli (E. coli), including that of a multidrug-resistant E. coli (MDR E. coli), were investigated during the photolysis of TC. A photolysis product of TC (PPT) was generated in an alkaline solution after the illumination of a blue light. The mass spectra of PPT had characteristic ion signals in m/z 459, 445, and 249.1 Da. The PPT has the molecular formula of C22H22N2O9, and the exact mass is 458.44 g/mol. The inactivation of MDR E. coli is not significant with TC treatment. The drug-resistant ability of MDR E. coli has a less significant effect on PPT, and the changed conformation of TC retained the inactivation ability of MDR E. coli upon blue light photoreaction. With TC, illuminated by a blue light in a pH 7.8 PBS, O2•− was generated from TC photolysis, which enhanced the inactivation of E. coli and MDR E. coli. A 96.6% inactivation rate of MDR E. coli was reached with TC under 2.0 mW/cm2 blue light illumination at 25 ± 3 °C for 120 min, and the effects of the TC-treated photoreaction on MDR E. coli viability repressed the growth of MDR E. coli by 4 to 5 logs. The present study of the blue light photoreaction of TC offers a new approach to the inactivation of MDR E. coli.

【 授权许可】

Unknown