蔗糖及木糖醇对血链球菌和变异链球菌相互作用的影响

摘要

目的：研究不同浓度的蔗糖、木糖醇对血链球菌（S．s）产生过氧化氢（H2 O2）能力及血链球菌与变异链球菌（S．m）相互作用的影响。方法：采用邻联茴香胺－辣根过氧化物酶法测定有氧环境中不同浓度蔗糖、木糖醇对 S．s 产生 H2 O2的影响，通过平板培养法观察不同浓度蔗糖、木糖醇对有氧、厌氧环境中 S．s、S．m 相互作用的影响。结果：有氧环境下，S．s 在不同浓度的蔗糖、木糖醇培养基中培养6 h 累积产生 H2 O2的量由高到低 BHI ＋50 mmol／L 蔗糖组＞BHI ＋5 mmol／L 蔗糖组＞BHI 组＞BHI ＋5 mmol／L 木糖醇组＞BHI ＋50 mmol／L木糖醇组（P ＜0．05）；6 h 时，菌悬液 A600值标准化之后的相对 H2 O2量为 BHI 组＞BHI ＋5 mmol／L 蔗糖组＞BHI ＋50 mmol／L 蔗糖组＞BHI ＋5 mmol／L 木糖醇组＞BHI ＋50 mmol／L 木糖醇组（P ＜0．05）。同时接种两种细菌在有氧、厌氧环境均中未观察到相互抑制的作用；先接种 S．m，对 S．s 的抑制作用在50 mmol／L 蔗糖中最明显，同种培养基中厌氧环境下的抑制作用强于有氧环境；先接种 S．s，对 S．m 的抑制作用在50 mmol／L 蔗糖中最明显，同种培养基中有氧环境下的抑制作用强于厌氧环境。结论：S．s 在不同含糖培养基中产生 H2 O2的能力不同；S．s 与 S．m 的相互作用受到接种顺序、外源性糖及环境中氧的影响。%AIM:To investigate the influence of different concentrations of sucrose and xylitol on the pro-duction of hydrogen peroxide by Streptococcus sanguis (S.s)and the interaction between S.s and Streptococcus mutans (S.m).MTHODS:The production of H2 O2 by S.s was determined by o -Dianisidine dihydrochloride -horseradish peroxidase with different sucrose and xylitol concentrations.The interaction between S.s and S.m was observed by plat-ing method with carbohydrates in both aerobic and anaerobic environment.RESULTS:Under aerobic environment with different carbohydrates the total production of H2 O2 by S.s was as following:BHI +50 mmol/L sucrose >BHI +5 mmol/L sucrose >BHI >BHI +5 mmol/L xylitol >BHI +50 mmol/L xylitol(P <0.05).After H2 O2 concentration being adjusted to the absorbance of the bacteria suspession at 600 nm,the result was BHI >BHI +5 mmol/L sucrose >BHI +50 mmol/L sucrose >BHI +5 mmol/L xylitol >BHI +50 mmol/L xylitol(P <0.05).The inhibition was not ob-served when S.s and S.m were inoculated simultaneously.The H2 O2 production inhibition was the strongest when the bacteria were culture with 50 mmol/L sucrose and stronger in anaerobic environment when S.m was inoculated first. The inhibition was the strongest with 50 mmol/L sucrose and stronger in aerobic environment when S.s was inoculated first.CONCLUSION:The H2 O2 production by S.s is influenced by sucrose and xylitol concentrations .The interac-tion of S.s on S.m is influenced by inoculation time and sequences,different kind of carbohydrates and the oxygen con-centration.