title: The Bioeffects Resulting from Prokaryotic Cells and Yeast Being Exposed to an 18 GHz Electromagnetic Field.
abstract: The mechanisms by which various biological effects are triggered by exposure to an electromagnetic field are not fully understood and have been the subject of debate. Here, the effects of exposing typical representatives of the major microbial taxa to an 18 GHz microwave electromagnetic field (EMF)were studied. It appeared that the EMF exposure induced cell permeabilisation in all of the bacteria and yeast studied, while the cells remained viable (94% throughout the exposure), independent of the differences in cell membrane fatty acid and phospholipid composition. The resulting cell permeabilisation was confirmed by detection of the uptake of propidium iodine and 23 nm fluorescent silica nanospheres using transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). Upon EMF exposure, the bacterial cell membranes are believed to become permeable through quasi-endocytosis processes. The dosimetry analysis revealed that the EMF threshold level required to induce the uptake of the large (46 nm) nanopsheres was between three and six EMF doses, with a specific absorption rate (SAR) of 3 kW/kg and 5 kW/kg per exposure, respectively, depending on the bacterial taxa being studied. It is suggested that the taxonomic affiliation and lipid composition (e.g. the presence of phosphatidyl-glycerol and/or pentadecanoic fatty acid) may affect the extent of uptake of the large nanospheres (46 nm). Multiple 18 GHz EMF exposures over a one-hour period induced periodic anomalous increases in the cell growth behavior of two Staphylococcus aureus strains, namely ATCC 25923 and CIP 65.8T.
authors.affiliation: Faculty Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, Hawthorn, Vic 3122, Australia.
authors.forename: The Hong Phong
authors.initials: TH
authors.lastname: Nguyen
authors.affiliation: Faculty Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, Hawthorn, Vic 3122, Australia.
authors.forename: Vy T H
authors.initials: VT
authors.lastname: Pham
authors.affiliation: Faculty Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, Hawthorn, Vic 3122, Australia.
authors.forename: Song Ha
authors.initials: SH
authors.lastname: Nguyen
authors.affiliation: Department d'Enginyeria Quimica, Universitat Rovira I Virgili, 26 Av. dels Paisos Catalans, 43007 Tarragona, Spain.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Baulin
authors.affiliation: School of Psychology, University of Wollongong, Wollongong, NSW 2522, Australia.
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Croft
authors.affiliation: Faculty Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, Hawthorn, Vic 3122, Australia.
authors.forename: Brian
authors.initials: B
authors.lastname: Phillips
authors.affiliation: Faculty Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, Hawthorn, Vic 3122, Australia.
authors.forename: Russell J
authors.initials: RJ
authors.lastname: Crawford
authors.affiliation: Faculty Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, Hawthorn, Vic 3122, Australia.
authors.forename: Elena P
authors.initials: EP
authors.lastname: Ivanova
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D004574:Electromagnetic Fields; D005227:Fatty Acids / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D018613:Microscopy, Confocal; D046529:Microscopy, Electron, Transmission; D008872:Microwaves; D054118:Nanospheres / Q000737:chemistry; D010539:Permeability; D011419:Propidium / Q000737:chemistry; D011829:Radiation Dosage; D012441:Saccharomyces cerevisiae / Q000528:radiation effects*; D013211:Staphylococcus aureus / Q000528:radiation effects*
chemical_list: D005227:Fatty Acids; D008055:Lipids; D011419:Propidium