Effects of exposure to mobile phone induced-electromagnetic field on Staphylococcus aureus / Mohd Saufee Al Firdaus Mohd Ismail

Effects of electromagnetic (EMF) field on microorganisms related to human had caught many attentions in line with the development and usage of new technology worldwide. The closest EMF inducer to human nowadays appeared to be mobile phones. Staphylococcus aureus (SA) had been reported as both a major culprit of diseases and a natural protective barrier (in the ear) to human. To date, knowledge on phenotypical changes of S. aureus exposed to EMF has not been documented in detail. The aim of this study was to investigate the effects imposed by EMF of a mobile phone on the phenotypic characteristics of S. aureus. Two conditions of radiation, standby-mode and on-call mode, at four different durations, 15, 30, 45 and 60 minutes, were executed. The effects of these conditions on the radiated S. aureus were evaluated based on comparisons made with the non-radiated S. aureus. The radiated S. aureus was studied on the viability and changes in growth pattern; morphology differences; biochemical reactivity level; the deviation of antimicrobial sensitivity and biofilm production in comparison to non-radiated strains. The viability study had shown that growth of S. aureus was enhanced under the standby condition while the on-call condition, growth was suppressed. These two outcomes were influenced by the differences in the strength and duration of exposure of the EMF. No change in the growth curve pattern was observed for the irradiated S. aureus. The morphology of the S. aureus when viewed under direct light and scanning electron microscopes had showed that the shape and arrangement of the organism was highly preserved. The biochemical properties and antimicrobial sensitivity of S. aureus was not affected while the quantification of biofilm had shown a slight deviation in the glycocalyx production compared to normal. It is postulated that the complexity of the cell wall is one of the major contributors to the compensatory mechanism of adaption of the survived cells.