Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.
Caries Res. 2012;46(3):185-93. doi: 10.1159/000337307. Epub 2012 Apr 13.
Dental caries is the most prevalent human infection. It is a multifactorial disease in which the microbial composition of dental plaque plays a major role in the development of clinical symptoms. The bacteria most often implicated in the development of caries are that group of streptococci referred to as the mutans streptococci, in particular Streptococcus mutans and Streptococcus sobrinus. One approach to the prevention of caries is to reduce the numbers of mutans streptococci in plaque to a level insufficient to support demineralization of the tooth. In this study, zoocin A, a peptidoglycan hydrolase, combined with lauricidin, a cell membrane active lipid, was shown over a 72 h period to selectively suppress the growth of S. mutans in a triple species biofilm. Growth of the non-target species Streptococcus oralis and Actinomyces viscosus was not inhibited. In treated systems the amount of extracellular polysaccharide matrix produced was much reduced as determined by use of fluorescein isothiocyanate conjugated wheat germ agglutinin. The pH of treated biofilms remained above neutral as opposed to a value of 4.3 in untreated controls. We conclude that use of antimicrobial compounds that specifically target cariogenic bacteria should be further explored.
龋齿是最常见的人类感染。它是一种多因素疾病，其中牙菌斑的微生物组成在临床症状的发展中起主要作用。最常与龋齿发展有关的细菌是那群被称为变形链球菌的链球菌，特别是变形链球菌和远缘链球菌。预防龋齿的一种方法是将菌斑中的变形链球菌数量减少到不足以支持牙齿脱矿的水平。在这项研究中，肽聚糖水解酶 zoocin A 与细胞膜活性脂质 lauricidin 联合使用，在 72 小时内选择性地抑制了三种物种生物膜中 S. mutans 的生长。非靶标物种 Streptococcus oralis 和 Actinomyces viscosus 的生长没有受到抑制。在处理系统中，通过使用异硫氰酸荧光素标记的麦胚凝集素测定，产生的细胞外多糖基质的量大大减少。与未经处理的对照组中 4.3 的值相比，处理过的生物膜的 pH 值保持在中性以上。我们得出结论，应该进一步探索使用专门针对致龋细菌的抗菌化合物。
