EVALUATION AND ENUMERATION OF ANTIBACTERIAL EFFECTS OF XYLITOL AGAINST PNEUMOCOCCAL GROWTH BY MTT ASSAY

Background and Aim:Xylitol as a five-carbon sugar alcohol has been widely used as a sweetener, mainly in chewing gums. Because of its antibacterial activity against acute otitis media in children qualitatively was reported. In this regards, quantitatively of antibacterial activity procedures may be crucial for Streptococcus pneumonia infections control. This study aimed was quantitative evaluate the antibacterial effect of xylitol on growth and survival of Streptococcus pneumoniae by MTT assay.Methods:Streptococcus pneumoniae ATCC strain 49619 were exposed to 2.5, 5 and 7.5% of xylitol with or without fructose in a period of 24 hours. During of incubation (Every three hours once) ,200 μl of each media was transferred to 96-well plate .Next 20 μl of MTT solution was added to each well and were incubated at 37°C in a 5%CO2 atmosphere. after 4 hours’ supernatant was removed and 50 μl DMSO was added to Dissolved blue colored formazan crystals. The plate was again incubated for 30 minute and OD rate was measured with ELISA reader in the wavelength of 570 nm.Results: Statistical analysis results has indicated a significant growth difference in the various test media which contain concentrations of 2.5, 5 and 7.5% of xylitol without fructose. (P value < 0.0001)Conclusion:the results revealed that the reductive effect of xylitol on growth and survival of Streptococcus pneumoniae. This finding supports previous results where exposure to xylitol changed the ultrastructure of the pneumococcal capsule and could explain further the high clinical efficacy of xylitol in preventing otitis media.

کلیدواژه ها:

Streptococcus pneumoniae ، xylitol ، MTT assay