Effect of xylitol and other carbon sources on Streptococcus pneumoniae biofilm formation and gene expression in vitro
Effect of xylitol and other carbon sources on Streptococcus pneumoniae biofilm formation and gene expression in vitro
复制标题
DOI：
10.1111/j.1600-0463.2010.02703.x
复制
发表时间：
2011-02-01
期刊：
影响因子：
2.8
通讯作者：
Saukkoriipi, Annika
中科院分区：
文献类型：
--
作者：
Kurola, Paula;Tapiainen, Terhi;Saukkoriipi, Annika
木糖醇抑制肺炎链球菌的生长。在临床试验中，木糖醇降低了日托儿童急性中耳炎的发生率，但没有降低肺炎球菌的鼻咽携带。我们假设木糖醇可以抑制肺炎球菌的生物膜形成，并在不同的体外生长培养基中测定了荚膜基因cpsB和另外两个基因（自溶素编码基因lytA和能力基因comA）的生物膜形成和基因表达水平。20株肺炎球菌分离株在聚苯乙烯板上生长18 h，试验培养基中含有0.5%木糖醇、0.5%葡萄糖、0.5%木糖醇和0.5%葡萄糖、0.5%果糖、0.5%木糖醇和0.5%果糖或添加10%马血清的脑心输注（BHI）培养基。生长5 h后，用校正器归一化的相对定量方法测定基因表达水平。与BHI培养基相比，木糖醇降低了作为生物膜指标的OD值，但当培养基中添加葡萄糖或果糖时，生物膜形成增强，木糖醇对生物膜形成的抑制作用未被观察到。木糖醇也降低了lytA的表达水平。在以往的临床试验中，木糖醇预防急性中耳炎的疗效可能部分解释了不同糖化合物对生物膜形成的影响。
Xylitol inhibits the growth of Streptococcus pneumoniae. In clinical trials, xylitol decreased the occurrence of acute otitis media in day-care children, but did not decrease nasopharyngeal carriage of pneumococci. We hypothesized that xylitol inhibits biofilm formation of pneumococci, and measured biofilm formation and gene expression levels of the capsule gene cpsB and two other genes: autolysin encoding gene lytA and competence gene comA in different growth media in vitro. Twenty pneumococcal isolates were grown on polystyrene plates for 18 h in test media containing 0.5% xylitol, 0.5% glucose, 0.5% xylitol and 0.5% glucose, 0.5% fructose, 0.5% xylitol and 0.5% fructose or brain heart infusion (BHI) medium supplemented with 10% horse serum. Gene expression levels were measured after 5 h of growth using a relative quantification method with calibrator normalization. Exposure to xylitol lowered OD values, which were used as an indication of biofilm, compared with BHI medium, but when the medium was supplemented with glucose or fructose, biofilm formation was enhanced and the inhibitory effect of xylitol on biofilm formation was not observed. Xylitol also lowered lytA expression levels. Changes in biofilm formation in response to different sugar compounds may partly explain the efficacy of xylitol to prevent acute otitis media in previous clinical trials.