Fine D H, Furgang D, Kaplan J, Charlesworth J, Figurski D H
Department of Oral Pathololgy and Biology, University of Medicine and Dentistry of New Jersey, New Jersey Dental School, Dental Research Center, Newark 07103, USA.
Arch Oral Biol. 1999 Dec;44(12):1063-76. doi: 10.1016/s0003-9969(99)00089-8.
Adherence of Actinobacillus actinomycetemcomitans to hard-tissue surfaces was evaluated by comparing a phenotypically stable, well-maintained clinical isolate (strain CU1000) to Streptococcus gordonii G9B, an extensively studied oral-colonizing bacterium. Standard innocula of radiolabelled bacteria were added to saliva-coated hydroxyapatite (SHA) and the ratio of bound to unbound cells counted. Several other clinical isolates as well as laboratory strain Y4 were studied. In other experiments, cell detachment from SHA was compared in static and shaking vessels to calculate controlled desorption of cells over time. A sonic-displacement assay was used to measure avidity of binding to HA and SHA. To better define the attachment properties of CU1000, bacteria were treated with a variety of agents including detergents, salts and enzymes before or after incubation with SHA. Results indicated that CU1000 bound better than G9B (a minimum of 10-fold greater; p < or = 0.05) and did not desorb from SHA, while G9B desorbed to equilibrium in 4 h. Furthermore, Langmuir isotherm calculations indicated that, unlike G9B, CU1000 did not follow second-order adsorption kinetics and thus did not achieve saturation. In addition, of the agents tested only periodate reduced attachment and resulted in detachment of CU1000 from surfaces. These experiments suggest that clinical isolates of A. actinomycetemcomitans possess unique binding properties that promote adsorption to and impede desorption from SHA. The characteristics described for the actinobacillus in this study have been previously underestimated, appear to be mediated by glycoconjugates, and may resemble attachment described for several biofilm-forming, non-oral pathogens.
通过将一株表型稳定、保存良好的临床分离株（CU1000菌株）与戈登链球菌G9B（一种经过广泛研究的口腔定植细菌）进行比较，评估了伴放线放线杆菌对硬组织表面的黏附情况。将放射性标记细菌的标准接种物添加到唾液包被的羟基磷灰石（SHA）上，计算结合细胞与未结合细胞的比例。还研究了其他几株临床分离株以及实验室菌株Y4。在其他实验中，比较了静态和振荡容器中细胞从SHA上的脱离情况，以计算细胞随时间的可控解吸。使用声波置换试验来测量与HA和SHA结合的亲和力。为了更好地定义CU1000的附着特性，在与SHA孵育之前或之后，用包括去污剂、盐和酶在内的多种试剂处理细菌。结果表明，CU1000的结合能力优于G9B（至少高10倍；p≤0.05），并且不会从SHA上解吸，而G9B在4小时内解吸至平衡。此外，朗缪尔等温线计算表明，与G9B不同，CU1000不遵循二级吸附动力学，因此不会达到饱和。此外，在所测试的试剂中，只有高碘酸盐降低了附着并导致CU1000从表面脱离。这些实验表明，伴放线放线杆菌的临床分离株具有独特的结合特性，可促进对SHA的吸附并阻碍从SHA上解吸。本研究中描述的放线杆菌的特性此前被低估，似乎是由糖缀合物介导的，并且可能类似于几种形成生物膜的非口腔病原体所描述的附着情况。
