Quiñones-Peña María A, Tavizon Gustavo, Puente José L, Martínez-Anaya Claudia, Hernández-Chiñas Ulises, Eslava Carlos A
Departamento de Salud Pública, Facultad de Medicina UNAM, Ciudad de México, México.
Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato-Oncología e Investigación Hospital Infantil de México Federico Gómez/División de Investigación, Facultad de Medicina UNAM, Ciudad de México, México.
Bioelectromagnetics. 2017 Oct;38(7):570-578. doi: 10.1002/bem.22077. Epub 2017 Aug 25.
This study reports the effects of exposing cells of the prototypical enteropathogenic Escherichia coli (EPEC) strain E2348/69 to static magnetic fields (SMF) of varying intensities to observe their capacity to autoaggregate and the effect on cell adherence. The results showed that bacteria exposure over the course of 5 min to an intensity of 53 mT reduced autoaggregation by 28%. However, with intensities of up to 100 mT with the same exposure time, bacteria autoaggregation was reduced by approximately 50%; and after 30 min at the same intensity, it was indistinguishable from that observed in a non-autoaggregative strain. Furthermore, it was observed that SMF treatment also modified the typical localized adherence pattern of EPEC E2348/69. The observed effects are not related to bacteria damage. The above was confirmed because, after a 107 mT SMF treatment over the course of 30 min, cell viability and membrane permeability were the same to that observed in untreated controls. The obtained results suggest that the SMF effect on the E2348/69 EPEC strain alters the expression of the bundle-forming pilus (BFP), due to the fact that the same strain without the EPEC adherence factor plasmid that encodes the BFP operon was unable to autoaggregate. Electron microscopic analyses revealed structural differences between cells exposed to SMF with respect to untreated controls. In conclusion, the SMF treatment of 107 mT for 30 min reduced EPEC E2348/69 autoaggregation and modified its adherence pattern, with both events likely being associated with changes in BFP expression. Bioelectromagnetics. 38:570-578, 2017. © 2017 Wiley Periodicals, Inc.
本研究报告了将典型的肠致病性大肠杆菌（EPEC）菌株E2348/69的细胞暴露于不同强度的静磁场（SMF）下，观察其自聚集能力以及对细胞黏附的影响。结果表明，在5分钟内将细菌暴露于强度为53 mT的磁场中，自聚集减少了28%。然而，在相同暴露时间下，磁场强度高达100 mT时，细菌自聚集减少了约50%；在相同强度下处理30分钟后，其自聚集情况与非自聚集菌株无异。此外，还观察到SMF处理也改变了EPEC E2348/69典型的局部黏附模式。观察到的这些效应与细菌损伤无关。这一点得到了证实，因为在30分钟内进行107 mT的SMF处理后，细胞活力和膜通透性与未处理的对照相同。所得结果表明，SMF对E2348/69 EPEC菌株的影响改变了束状菌毛（BFP）的表达，因为同一菌株在没有编码BFP操纵子 的EPEC黏附因子质粒时无法自聚集。电子显微镜分析揭示了暴露于SMF的细胞与未处理对照在结构上的差异。总之，107 mT的SMF处理30分钟可减少EPEC E2348/69的自聚集并改变其黏附模式，这两个事件可能都与BFP表达的变化有关。《生物电磁学》。2017年；38:570 - 578。© 2017威利期刊公司。
