Study of Gentamicin Effect on Staphylococcus Aureus in the Presence of Electromagnetic Field

Abstract

Introduction: Nowadays the medical, therapeutic and pharmacological application of magnetic fields (MF) and its biological effect has raised question about the safety of MF. This study aimed at scrutinizing the effect of static MF on the resistance of S. aureus to antibiotic. Materials and Methods: This prospective, case–control study was conducted to evaluate the effect of low intensity (0.5 mT) static MF on the growth rate and the antibiotic resistance of S. aureus sensitive to gentamicin. The studied bacterium is a nosocomial type and the growth rate was calculated by colony counting to understand the effect of MF on it. In the next stage, the rate of bacterial growth along with the different concentration of antibiotic was studied and the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were determined. Results: It is concluded that the 0.5 mT MF didn't affect the growth rate of S. aureus after 24 and 48 hours. The 0.5 mT MF induced a 50 percent decline of MIC and MBC of gentamicin after a 48 hour incubation (MIC = 4 6g /cc, MBC = 8 6g /cc in the case group vs. MIC = 8 6g /cc, MBC = 16 6g /cc in the control group). Conclusion: Low–intensity MF didn't affect the bacterial growth rate. However, the bactericidal effects of gentamicin were greater in the presence of MF. It is possible to apply the static MF for enhancing the effect of antibiotic on S. aureus.