A Porphyromonas gingivalis Mutant Defective in a Putative Glycosyltransferase Exhibits Defective Biosynthesis of the Polysaccharide Portions of Lipopolysaccharide, Decreased Gingipain Activities, Strong Autoaggregation, and Increased Biofilm Formation
A Porphyromonas gingivalis Mutant Defective in a Putative Glycosyltransferase Exhibits Defective Biosynthesis of the Polysaccharide Portions of Lipopolysaccharide, Decreased Gingipain Activities, Strong Autoaggregation, and Increased Biofilm Formation
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DOI：
10.1128/iai.00071-10
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发表时间：
2010-07
影响因子：
3.1
通讯作者：
Mikiyo Yamaguchi;Keiko Sato;H. Yukitake;Y. Noiri;S. Ebisu;K. Nakayama
中科院分区：
文献类型：
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作者：
Mikiyo Yamaguchi;Keiko Sato;H. Yukitake;Y. Noiri;S. Ebisu;K. Nakayama
摘要牙周病是一种由生物被膜引起的感染性疾病，其主要病原菌为牙周炎的革兰氏阴性厌氧菌。该菌具有潜在的毒力因子，包括菌毛、蛋白酶、血凝素、脂多糖(LPS)和外膜小泡，其中一些因子与生物膜的形成有关，但生物膜形成的确切机制尚不清楚。细菌在血液琼脂平板上的菌落色素沉着与其毒力有关。在本研究中，我们通过筛选转座子插入文库，分离到了一个在新基因PGN_1251(GTFB)中有插入突变的无色素突变体。该基因与几种细菌的糖基转移酶1编码基因有同源性。GTFB突变株在含有O侧链多糖(O-LPS)和阴离子多糖(A-LPS)的LPS生物合成方面存在缺陷。该基因的缺陷导致表面相关的牙周炎蛋白水解酶的完全丧失、强烈的自聚集性和生物膜形成的显著增加，这表明LPS的多糖组分影响牙周炎蛋白水解酶在细胞表面的附着、自聚集和生物膜的形成。
ABSTRACT The Gram-negative anaerobic bacterium Porphyromonas gingivalis is a major pathogen in periodontal disease, one of the biofilm-caused infectious diseases. The bacterium possesses potential virulence factors, including fimbriae, proteinases, hemagglutinin, lipopolysaccharide (LPS), and outer membrane vesicles, and some of these factors are associated with biofilm formation; however, the precise mechanism of biofilm formation is still unknown. Colonial pigmentation of the bacterium on blood agar plates is related to its virulence. In this study, we isolated a nonpigmented mutant that had an insertion mutation within the new gene PGN_1251 (gtfB) by screening a transposon insertion library. The gene shares homology with genes encoding glycosyltransferase 1 of several bacteria. The gtfB mutant was defective in biosynthesis of both LPSs containing O side chain polysaccharide (O-LPS) and anionic polysaccharide (A-LPS). The defect in the gene resulted in a complete loss of surface-associated gingipain proteinases, strong autoaggregation, and a marked increase in biofilm formation, suggesting that polysaccharide portions of LPSs influence attachment of gingipain proteinases to the cell surface, autoaggregation, and biofilm formation of P. gingivalis.