Wheeldon L J, Worthington T, Lambert P A
Microbiology, Life and Health Sciences, Biomedical Sciences, Aston University, Aston Triangle, Birmingham, UK.
J Appl Microbiol. 2011 Apr;110(4):987-94. doi: 10.1111/j.1365-2672.2011.04953.x.
It is well established that the bile salt sodium taurocholate acts as a germinant for Clostridium difficile spores and the amino acid glycine acts as a co-germinant. The aim of this study was to determine whether any other amino acids act as co-germinants.
Clostridium difficile spore suspensions were exposed to different germinant solutions comprising taurocholate, glycine and an additional amino acid for 1 h before heating shocking (to kill germinating cells) or chilling on ice. Samples were then re-germinated and cultured to recover remaining viable cells. Only five amino acids out of the 19 common amino acids tested (valine, aspartic acid, arginine, histidine and serine) demonstrated co-germination activity with taurocholate and glycine. Of these, only histidine produced high levels of germination (97·9-99·9%) consistently in four strains of Cl. difficile spores. Some variation in the level of germination produced was observed between different PCR ribotypes, and the optimum concentration of amino acids with taurocholate for the germination of Cl. difficile NCTC 11204 spores was 10-100 mmol l-1.
Histidine was found to be a co-germinant for Cl. difficile spores when combined with glycine and taurocholate.
众所周知，牛磺胆酸钠盐作为艰难梭菌孢子的萌发剂，而氨基酸甘氨酸作为共萌发剂。本研究的目的是确定是否有其他氨基酸作为共萌发剂。
将艰难梭菌孢子悬液暴露于含有牛磺胆酸盐、甘氨酸和另一种氨基酸的不同萌发剂溶液中1小时，然后进行热激处理（以杀死正在萌发的细胞）或在冰上冷却。然后将样品重新萌发并培养以回收剩余的活细胞。在测试的19种常见氨基酸中，只有5种氨基酸（缬氨酸、天冬氨酸、精氨酸、组氨酸和丝氨酸）表现出与牛磺胆酸盐和甘氨酸的共萌发活性。其中，只有组氨酸在四株艰难梭菌孢子中始终产生高水平的萌发（97.9%-99.9%）。在不同的PCR核糖型之间观察到萌发水平的一些差异，并且对于艰难梭菌NCTC 11204孢子的萌发，与牛磺胆酸盐一起使用的氨基酸的最佳浓度为10-100 mmol l-1。
发现组氨酸与甘氨酸和牛磺胆酸盐结合时是艰难梭菌孢子的共萌发剂。
