School of Chemical Technology, Kalinga Institute of Industrial Technology (KIIT), Bhubaneswar, India; School of Biotechnology, Kalinga Institute of Industrial Technology (KIIT), Bhubaneswar, India.
Department of Life Sciences, National Institute of Technology, Rourkela, India.
J Colloid Interface Sci. 2018 Nov 15;530:610-623. doi: 10.1016/j.jcis.2018.07.020. Epub 2018 Jul 6.
Water contamination by multidrug resistant (MDR) enteric bacteria can be considered as the foremost cause of gastrointestinal infections and poses a threat to global public health. Therefore, there is an urgent need to pursue unorthodox techniques with potential of community scale applications for purging of water borne pathogenic bacteria. We communicate visible-light assisted photocatalytic disinfection (PCD) of an enteric MDR bacterium; Enterobacter sp. using Fe-doped ZnO nanoparticles impregnated on Kaolinite (Clay) (ZnO/K). ZnO/K was synthesized by co-precipitation technique and was found to be more effective than Fe-doped ZnO (ZnO) and Kaolinite for PCD process. Analysis from fluorescence microscopy and electron microscopy (FESEM) proposed complete bacterial cell death via PCD due to damage of bacterial cell membrane. Experimental evidences indicated that O could be acting as the most significant component in disinfection of MDR Enterobacter sp. in visible-light assisted PCD process in presence of ZnO/K. Considering the experimental data of Resazurin assay, it is proposed that reactive oxygen species (ROS) generated during PCD might have impeded the oxido-reductase enzyme system of the bacteria and hence trammeling its metabolic activity. Crystal structure and particle size of ZnO/K was found to be unaltered during the photocatalytic process indicating its potential for reusability. When ZnO/K was exposed to HCT-116 Human Colorectal Carcinoma cell lines, about 79% cell survivability was noticed. The synthesized material was successful in completely disinfecting the target microorganism in Zebra Fish model, without producing any adverse effects on the Fish itself, further reinforcing its biocompatibility factor. High effectiveness of PCD process using ZnO/K under visible light in disinfecting enteric MDR bacteria, might have promising outcome as an alternative water disinfection technology to prevent the spread of infectious and resistant bacteria without producing any adverse effect on non-specific flora and fauna.
肠道耐药菌（MDR）导致的水污染可被视为胃肠道感染的首要原因，并对全球公共健康构成威胁。因此，迫切需要开发具有社区规模应用潜力的非常规技术来清除水中的致病细菌。我们报告了可见光辅助光催化消毒（PCD）对肠道耐药菌肠杆菌属的作用；利用 Fe 掺杂 ZnO 纳米颗粒负载在高岭土（粘土）上（ZnO/K）。通过共沉淀技术合成了 ZnO/K，发现其在 PCD 过程中比 Fe 掺杂 ZnO（ZnO）和高岭土更有效。荧光显微镜和电子显微镜（FESEM）分析提出，由于细菌细胞膜的损伤，PCD 可导致细菌完全死亡。实验证据表明，在可见光照辅助 PCD 过程中，O 可能是 ZnO/K 存在时消毒 MDR 肠杆菌属的最重要成分。考虑到 Resazurin 测定的实验数据，我们提出，PCD 过程中生成的活性氧（ROS）可能会干扰细菌的氧化还原酶系统，从而阻碍其代谢活性。在光催化过程中，ZnO/K 的晶体结构和粒径没有发生变化，表明其具有潜在的可重复使用性。当 ZnO/K 暴露于 HCT-116 人结肠癌细胞系时，约有 79%的细胞存活率。合成材料在斑马鱼模型中成功地完全消毒了目标微生物，而对鱼本身没有产生任何不良影响，进一步增强了其生物相容性因素。在可见光下使用 ZnO/K 的 PCD 过程具有高效性，可作为一种替代水消毒技术，用于防止传染性和耐药性细菌的传播，而不会对非特异性动植物区系产生任何不利影响。
