Haubek D, Dirienzo J M, Tinoco E M, Westergaard J, López N J, Chung C P, Poulsen K, Kilian M
Department of Oral Biology, University of Aarhus, Denmark.
J Clin Microbiol. 1997 Dec;35(12):3037-42. doi: 10.1128/jcm.35.12.3037-3042.1997.
Actinobacillus actinomycetemcomitans strains with enhanced levels of production of leukotoxin are characterized by a 530-bp deletion from the promoter region of the leukotoxin gene operon. Previous isolates with this deletion constituted a single clone belonging to serotype b, although they displayed minor differences among each other. We have analyzed the geographic dissemination of this clone by examining 326 A. actinomycetemcomitans isolates from healthy and periodontally diseased individuals as well as from patients with different types of extraoral infections originating from countries worldwide. A total of 38 isolates, all belonging to the same clone, showed the 530-bp deletion. Comparison of a 440-bp sequence from the promoter region of the leukotoxin gene operon from 10 of these strains revealed complete identity, which indicates that the deletion originates from a single mutational event. This particular clone was exclusively associated with localized juvenile periodontitis (LJP). In at least 12 of 28 families from which the clone was isolated, more than one family member had LJP. Notably, all the subjects carrying this clone had a genetic affiliation with the African population. These observations suggest that juvenile periodontitis in some adolescents with an African origin is associated with a disseminating clone of A. actinomycetemcomitans.
白细胞毒素产生水平增强的伴放线放线杆菌菌株的特征是白细胞毒素基因操纵子启动子区域有530bp的缺失。先前分离出的带有这种缺失的菌株构成了一个属于血清型b的单一克隆，尽管它们彼此之间存在细微差异。我们通过检测来自世界各地健康和患有牙周疾病的个体以及患有不同类型口外感染的患者的326株伴放线放线杆菌，分析了该克隆的地理传播情况。共有38株分离株，均属于同一克隆，显示出530bp的缺失。对其中10株菌株白细胞毒素基因操纵子启动子区域440bp序列的比较显示完全相同，这表明该缺失源自单一突变事件。这个特定的克隆仅与局限性青少年牙周炎（LJP）相关。在分离出该克隆的28个家庭中，至少有12个家庭中有不止一名家庭成员患有LJP。值得注意的是，所有携带该克隆的个体在基因上都与非洲人群有关联。这些观察结果表明，一些具有非洲血统的青少年的青少年牙周炎与伴放线放线杆菌的一个传播克隆有关。
