Trichomonas vaginalis and giardia lamblia growth alterations by low-frequency electromagnetic fields

Background: There is an increasing interest in using physical factors such as magnetic fields as antimicrobial strategy, with variable results. The current study was aimed to evaluate the influence of extremely low-frequency electromagnetic fields (ELF-EMFs) on the axenically-cultured parasite protozoans Trichomonas vaginalis and Giardia lamblia growth. Methods: Bioassays were developed using T. vaginalis, GT-13 and G. lamblia IMSS-0989 strains cultured at 37 ºC in TYI-S-33 medium. The following treatment regimens and controls were considered: (a) cells exposed to ELF-EMFs, (b) untreated cells, (c) cells treated with Metronidazole, used as positive controls, and (d) cells co-exposed to ELF-EMFs and Metronidazole. When cultures reached the end of logarithmic phase, they were exposed to ELF-EMFs for 72 h, in a standardized magnetic field exposure facility. For determining cytotoxic effects, trophozoite density was blindly evaluated in a Neubauer chamber. Results: A significant decrease in trophozoite growth was observed for T. vaginalis, in magnetic field-treated cultures. On the other hand, cultures co-exposed to ELF-EMFs and Metronidazole showed no significant differences when compared with cultures treated with Metronidazole alone. On the contrary, an increased trophozoite density was observed in G. lamblia cultures after exposure to magnetic fields. An absence of a synergistic or antagonistic effect was observed. Conclusion: ELF-EMFs induced T. vaginalis and G. lamblia growth alterations, indicating a potential effect in cell cycle progression.