Porphyromonas gingivalis galE is involved in lipopolysaccharide O-antigen synthesis and biofilm formation
Porphyromonas gingivalis galE is involved in lipopolysaccharide O-antigen synthesis and biofilm formation
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DOI：
10.1128/iai.00261-06
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发表时间：
2006-11-01
影响因子：
3.1
通讯作者：
Watanabe, Haruo
中科院分区：
文献类型：
--
作者：
Nakao, Ryoma;Senpuku, Hidenobu;Watanabe, Haruo
牙龈卟啉单胞菌是在口腔中形成的复合菌斑生物膜的关键组分，导致牙周病的进展。为了阐明牙周生物膜形成的机制，我们分析了牙龈卟啉单胞菌中与多糖合成相关的几个基因的参与。通过插入ermF-ermAM盒构建基因敲除牙龈卟啉单胞菌突变体;在这些突变体中，galE突变体显示出涉及GalE活性丧失的一些特征表型。如所预期的，与亲本菌株相反，galE突变体在0.1%半乳糖存在下积累细胞内碳水化合物，并且在浓度大于1%的半乳糖存在下不生长。脂多糖（LPS）分析表明，galE突变体的O-抗原链的长度比野生型的短。还证明了由galE突变体产生的生物膜具有比野生型的生物膜大4.5倍的强度。此外，发现galE突变体与野生型相比对某些抗生素显著敏感。此外，galE突变的互补导致亲本表型的部分恢复。我们得出的结论是，galE基因在牙龈卟啉单胞菌中LPS O抗原的修饰和生物膜形成中发挥着关键作用，并认为我们对牙龈卟啉单胞菌galE基因功能与生物膜形成等毒力表型之间关系的发现可能提供线索了解牙周病的致病机制。
porphyromonas gingivalis is a crucial component of complex plaque biofilms that form in the oral cavity, resulting in the progression of periodontal disease. To elucidate the mechanism of periodontal biofilm formation, we analyzed the involvement of several genes related to the synthesis of polysaccharides in P. gingivalis. Gene knockout P. gingivalis mutants were constructed by insertion of an ermF-ermAM cassette; among these mutants, the galE mutant showed some characteristic phenotypes involved in the loss of GalE activity. As expected, the galE mutant accumulated intracellular carbohydrates in the presence of 0.1% galactose and did not grow in the presence of galactose at a concentration greater than 1%, in contrast to the parental strain. Lipopolysaccharide (LPS) analysis indicated that the length of the O-antigen chain of the galE mutant was shorter than that of the wild type. It was also demonstrated that biofilms generated by the galE mutant had an intensity 4.5-fold greater than those of the wild type. Further, the galE mutant was found to be significantly susceptible to some antibiotics in comparison with the wild type. In addition, complementation of the galE mutation led to a partial recovery of the parental phenotypes. We concluded that the galE gene plays a pivotal role in the modification of LPS O antigen and biofilm formation in P. gingivalis and considered that our findings of a relationship between the function of the P. gingivalis galE gene and virulence phenotypes such as biofilm formation may provide clues for understanding the mechanism of pathogenicity in periodontal disease.