Document Type: Research Article
Department of Pathobiology, Faculty of Veterinary Specialized Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
Department of Microbiology, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran
Faculty of Medical Mycology, Tarbiat Modares University, Tehran, Iran
To date, registered users of mobile phone communication network exceeded from total numbers of the world population, while a little knowledge of the biological effects of, 900-1800 MHz microwave radiation, originating from the handsets or the base transceiver stations, have been released. The current study was designed for evaluation of 900-MHz radiation effects on Candida albicans proliferation, adherence and alpha-Int1 gene expression.
Candida albicans (ATCC:10231) grown in Yeast Peptone Dextrose (YPD) broth was distributed into five tubes (5 ml, 10^6 cells/ml) and exposed to 900 MHz GSM radiation for 6, 12, 18 and 24 hours, while the fifth tube was kept far from the radiation. Cell densities at 0, 6, 12, 18 and 24 hours were assayed (using turbidimetry in 600 nm). Equal cell densities (2.5 x 10^6 cells/ml, 200 ul) from exposed and unexposed yeasts were transferred into 96 well plates and incubated for 4 hours, in order to biofilm formation by the yeast. Yeast densities in biofilm network were assayed using the MTT method. Abundance of alpha-int1 mRNA was also estimated in the five yeast samples using q-RT-PCR method.
Microwave exposure led to increased proliferation rate and increased biofilm formation by the yeast and the effect was prominent in 18 hours exposed samples. Quantitative RT-PCR results showed significantly increased levels of the alpha-int1 mRNA in microwave exposed yeasts.
The significant increases in the yeast proliferation and biofilm formation after exposure to 900 MHz GSM radiation are partly mediated by changes in alpha-int1 protein expression.