LYSOGENY IN ACTINOBACILLUS ACTINOMYCETEMCOMITANS

伴放线放线杆菌是一种革兰氏阴性菌 它与多种形式的牙周病密切相关。 在人类身上。许多毒力因子被认为是由阿尔法病毒引起的 包括：白毒素、内毒素、骨吸收因子、胶囊、 胶原酶、酸性和碱性磷酸酶、成纤维细胞抑制物 一种淋巴细胞抑制因子和一种免疫调节血清型- 特定的表面抗原。为了解遗传决定因素所做的努力 因为这些因素被暂时整合的存在所阻碍 Apha中的外源遗传成分，以前驱体的形式存在。什么时候 温带细菌病毒裂解细菌，形成前驱体 经常赋予它们感染的细菌新的特性。非常 通常，这些新的特性显著增加了病毒的致病性 宿主细胞。毒素产生、毒素释放、血清等特性 敏感性、外膜结构改变、抗原性改变，以及 被膜形成的改变都是已知的由噬菌体介导的 感染。最近的发现表明，噬菌体感染是 在甲型流感病毒株中广泛流行。因此，在不知道是哪种情况下 Apha菌株是溶原性的，而哪些(如果有的话)不是，它将是 即使不是不可能，也很难知道哪些致病因子是内在的 Aslpha，这可归因于外源基因的表达 通过病毒感染进入细胞的遗传信息。 本提案中描述的实验旨在确定 病毒感染在AAlpha株中的分布。他们会 确定哪些是溶原性的Apha菌株，哪些是 不含噬菌体。因为至少有4个不同AAlpha 已知的噬菌体，本申请中提出的程序也是 旨在识别每个已知的Apha的分布 溶原性Apha菌株中的噬菌体。代表性菌株 将获得每个已知的Apha形态类型(A、B1、B2、C)的 来自诱导的α-溶原菌。从它们的基因组中制备的DNA探针 的噬菌体将用于筛选Apha菌株的DNA 与噬菌体DNA同源的序列，从而鉴定α-溶原菌。 此外，将采用腌制程序来消除噬菌体。 溶原性菌株的感染。这些程序预计会导致 在产生具有特定遗传结构的Apha菌株时 细菌病毒感染的术语。这样的AAlpha菌株将被 可供研究界用来确定 用阿尔法表示的毒性。

Actinobacillus actinomycetemcomitans (Aalpha) is a gram-negative bacterium that has been closely associated with several forms of periodontal disease in man. Numerous virulence factors have been attributed to Aalpha including: a leukotoxin, an endotoxin, a bone resorbing factor, a capsule, a collagenase, acid and alkaline phosphatases, a fibroblast inhibitory factor, a lymphocyte suppressive factor, and an immunoregulatory serotype- specific surface antigen. Efforts to understand the genetic determinants for these factors are hindered by the presence of transiently integrated exogenous genetic elements in Aalpha, in the form of prophages. When temperate bacterial viruses lysogenize bacteria, the prophages formed frequently confer new properties on the bacteria that they infect. Very often, these new properties significantly increase the pathogenicity of the host cell. Properties such as toxin production, toxin release, serum sensitivity, altered outer membrane structure, altered antigenicity, and altered capsule formation, are all known to be mediated by bacteriophage infection. Recent findings suggest that bacteriophage infection is widespread among Aalpha strains. Consequently, without knowing which Aalpha strains are lysogenic and which (if any) are not, it would be difficult, if not impossible to know which virulence factors are intrinsic to Aslpha, and which are attributable to the expression of exogenous genetic information brought into the cell by viral infection. The experiments described in this proposal are designed to determine the distribution of viral infection among strains of Aalpha. They will identify those Aalpha strains that are lysogenic and those that are bacteriophage-free. Since there are at least 4 different Aalpha bacteriophages known, the procedures proposed in this application are also directed towards identifying the distribution of each of the known Aalpha bacteriophages among the lysogenic Aalpha strains. Representative isolates of each of the known Aalpha morphotypes (A, B1, B2, C) will be obtained from induced Aalpha lysogens. DNA probes prepared from the genomes of each of the Aalpha phages will be used to screen Aalpha strains for DNA sequences homologous to the phage DNA, thereby identifying Aalpha lysogens. Furthermore, curing procedures will be employed to eliminated phage infection from lysogenic strains. These procedures are expected to result in the generation of Aalpha strains of defined genetic constitution in terms of bacterial virus infection. Such Aalpha strains will then be available to the research community for determining the genetic basis for virulence in Alpha.