Characterization of the Structural Changes of the Genomic DNA of Staphylococcus aureus Due to Femtosecond Laser Irradiation by Fourier Transform Infrared (FT-IR) Spectroscopy

Medical application of femtosecond laser irradiation for possible cancer treatment is a primary interest for this study. In this study the effects of femtosecond laser irradiation time, treatment wavelength and strain type upon the structure of DNA from methicillin-resistant Staphylococcus aureus (strain I) and methicillin-susceptible Staphylococcus aureus (strain II) is presented using Fourier transform infrared (FT-IR) spectroscopy. Six sets of irradiation parameters are considered for the bacterial strains. Fourier transform infrared spectra of genomic nucleic acids extracted from the two Staphylococcus aureus bacterial strains were characterized for control and irradiated samples. FT-IR assignments and structure of nucleic acids subgroups were analyzed from 800 to 1800 cm(-1). In particular, the bands at 1074 cm(-1) [PO2- symmetric stretching (upsilon sPO2-)], 1233 cm(-1) (antisymmetric stretching upsilon aPO2-, possible A-form), 1330 cm(-1) [deoxyadenosine (dA)], 1400 cm(-1) (C3'-endo/anti, A-form), 1540 cm(-1) [deoxycytidine (dC)] and 1650 cm(-1) [deoxycytidine (dC) (C2 = O2)] were considered to evaluate the structural changes of DNA functional groups following irradiation.