ABSTRACT
Objective:To study the effect of extraneous sugar on rea ct ive oxygen species metabolism of Streptococcus mutans. Methods: Electron spin resonance (ESR) method was used to measure reactive oxygen spe cies of Streptococcus mutans incubated in the different sugar incubation con ditions. Results:With the increase of glucose at 0.0062~0.05 mo l/L, the quantities of reactive oxygen species produced by Streptococcus mutan s increased and increased to the maximum when Streptococcus mutans were in cubated in different sugar culture fluids within 2 h. All kinds of sugar promote d reactive oxygen species metabolism of Streptococcus mutans. Conclu sion:Extraneous sugar promotes reactive oxygen species metabolism of Streptococcus mutans.
ABSTRACT
Objective: To study the effect of methylene blue on the metabolism of reactive oxygen and acid production of Streptococcus mutans . Methods: Streptococcus of cricetusa, rattusb, mutansc, sobrinsd and mutans e,f and g were exposed to methylene blue at 2.5?10 -4 g/L for 1 h. The metabolism of reactive oxygen and acid production were detected by electron spin trapping method and gas chromatography respectively. Results: Electron spin resonance (ESR) spectrums of DMPO-O - ? 2 and DMPO-OH ? were observed in Streptococcus mutans cultured in glucose fluid, but were not found in those exposed to methylene. The total of acid production by Streptococcus mutans incubated with glucose + methylene blue were significantly lower than that with single glucose. Conclusion: Methylene blue may inhibit oxygen species metabolism and acid production of Streptococcus mutans , it may be used as a kind of dental caries prevention agent.