Qi Fengxia, Kreth Jens
College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
Methods Mol Biol. 2010;666:151-66. doi: 10.1007/978-1-60761-820-1_11.
Most bacteria in nature exist in multispecies communities known as biofilms. In the natural habitat where resources (nutrient, space, etc.) are usually limited, individual species must compete or collaborate with other neighboring species in order to perpetuate in the multispecies community. The human oral cavity is colonized by >700 microbial species known as the indigenous microflora. This indigenous flora normally maintains an ecological balance through antagonistic as well as mutualistic interspecies interactions. However, environmental perturbation may disrupt this balance, leading to overgrowth of pathogenic species, which could in turn initiate diseases such as dental caries (tooth decay) and periodontitis (gum disease). Understanding the mechanisms of diversity maintenance may help development of novel approaches to manage these "polymicrobial diseases." In this chapter, we will focus on a well-characterized form of biochemical warfare: bacteriocins produced by Streptococcus mutans, a primary dental caries pathogen, and H(2)O(2) produced by Streptococcus sanguinis, an oral commensal. We will describe detailed methodologies on the competition assay, isolation, purification, and characterization of bacteriocins.
自然界中的大多数细菌以生物膜的形式存在于多物种群落中。在资源（营养、空间等）通常有限的自然栖息地中，单个物种必须与其他邻近物种竞争或合作，以便在多物种群落中延续下去。人类口腔中定植着700多种被称为固有微生物群的微生物。这种固有菌群通常通过拮抗和互利的种间相互作用来维持生态平衡。然而，环境扰动可能会破坏这种平衡，导致致病物种过度生长，进而引发龋齿（蛀牙）和牙周炎（牙龈疾病）等疾病。了解多样性维持机制可能有助于开发管理这些“多微生物疾病”的新方法。在本章中，我们将重点关注一种特征明确的生化战形式：主要致龋病原体变形链球菌产生的细菌素，以及口腔共生菌血链球菌产生的H₂O₂。我们将描述关于细菌素竞争测定、分离、纯化和表征的详细方法。
