RESUMO
AIMS: To evaluate the in vitro effects of extremely low-frequency magnetic field (ELF-MF) on growth and biofilm formation by Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia cepacia and Stenotrophomonas maltophilia strains from cystic fibrosis patients. MATERIALS & METHODS: The motion of selected ions (Fe, Ca, Cu, Zn, Mg, K, Na) was stimulated by the ion resonance effect, then influence on growth and biofilm formation/viability was assessed by spectrophotometry or viability count. RESULTS: Generally, exposure to ELF-MF significantly increased bacterial growth and affected both biofilm formation and viability, although with differences with regard to ions and species considered. CONCLUSION: Exposure to ELF-MF represents a possible new approach for treatment of biofilm-associated cystic fibrosis lung infections.
Assuntos
Biofilmes/crescimento & desenvolvimento , Fibrose Cística/microbiologia , Bactérias Gram-Negativas/fisiologia , Campos Magnéticos , Staphylococcus aureus/fisiologia , Burkholderia cepacia/crescimento & desenvolvimento , Burkholderia cepacia/fisiologia , Bactérias Gram-Negativas/crescimento & desenvolvimento , Humanos , Canais Iônicos/metabolismo , Viabilidade Microbiana , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/fisiologia , Espectrofotometria Ultravioleta , Staphylococcus aureus/crescimento & desenvolvimento , Stenotrophomonas maltophilia/crescimento & desenvolvimento , Stenotrophomonas maltophilia/fisiologiaRESUMO
A series of experiments on rats have been performed, to study the effects of long time (50 days) exposure to electromagnetic fields of extremely low frequency (ELF, i.e. less than 100 Hz) and amplitude (non thermal), testing whether the metabolic processes would be affected. The background lies on recent observations on the behaviour of isolated enzymes in vitro exposed to EFL fields. In these experiments, the cyclotron (or Larmor) frequency of the metallic ion has been used to "stimulate" the metalloproteins redox-active site, thus obtaining a clear variation of the enzyme functionality. In this paper we have extended for the first time the check to more complex animal metabolism. The novelty of this approach implies that a large amount of data had to be analyzed since it was not possible, in principle, to select only a few parameters among all the potential effects. Several biochemical parameters have been evaluated by comparing their values during the periods of exposure (field ON) and non exposure (field OFF). The evidence that long term exposure to electromagnetic fields with a well defined frequency may have relevant effects on parameters such as body weight, blood glucose and fatty acid metabolism has been obtained.