Dextranases from oral bacteria: inhibition of water-insoluble glucan production and adherence to smooth surfaces by Streptococcus mutans

Author:

Schachtele C F,Staat R H,Harlander S K

Abstract

The effect of dextranases (EC 3.2.1.11) from the oral isolates Actinomyces israelii and Bacteroides ochraceus on water-insoluble glucan production by the Streptococcus mutans dextransucrase (EC 2.4.1.5) and sucrose-dependent adherence to smooth glass surfaces by S. mutans was studied. Collection on membrane filters of water-insoluble polysaccharides synthesized from radioactive sucrose was used to demonstrate the marked sensitivity of insoluble glucan formation to the presence of dextranase. Concentrations of A. israelii dextranase as low as 0.002 U/ml inhibited insoluble glucan formation by 60%. Similar results were obtained the the B. ochraceus enzyme. An assay for sucrose-stimulated adherence of S. mutans to smooth surfaces involved attachment of radioactively labeled nongrowing cells to the bottom of glass scintillation vials. This facile and sensitive assay was utilized to demonstrate that sucrose-dependent adherence was affected by low levels of dextranase from either A. israelii or B. ochraceus. Enzyme at 0.005 U/ml reduced adherence of S. mutans by 80%. Treatment of S. mutans cells previously attached to glass with low concentrations of the dextranases resulted in removal of 50% to 60% of the bacteria. The results indicate that dextranase-producing oral bacteria may affect sucrose-dependent colonization of S. mutans on the tooth surface and offer a possible explanation for both the difficulties involved in implanting this bacterium into the human mouth and the limited intraoral transmission of S. mutans from one tooth surface to another.

Publisher

American Society for Microbiology

Subject

Infectious Diseases,Immunology,Microbiology,Parasitology

Reference44 articles.

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3