Streptococcus gordonii Collagen-binding Domain Protein CbdA May Enhance Bacterial Survival in Instrumented Root Canals Ex Vivo
Streptococcus gordonii Collagen-binding Domain Protein CbdA May Enhance Bacterial Survival in Instrumented Root Canals Ex Vivo
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DOI：
10.1016/j.joen.2012.06.002
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发表时间：
2013-01-01
影响因子：
4.2
通讯作者：
Vickerman, M. Margaret
中科院分区：
文献类型：
--
作者：
Moses, Peter J.;Power, Daniel A.;Vickerman, M. Margaret
简介：粪肠球菌的表面相关胶原结合蛋白Ace被认为是导致牙髓感染中细菌持续存在的毒力因子。本研究的目的是确定在更丰富的口腔链球菌中发现的与Ace具有氨基酸序列相似性的蛋白质是否可以在潜在的增强牙髓感染中发挥类似的作用。方法：通过基因组序列计算机检索，鉴定戈登链球菌ace基因。通过等位基因置换构建了菌株DL 1的同基因衍生物，该衍生物在所鉴定的基因中具有破坏。在微量滴定板结合试验中，对亲本菌株和突变菌株结合固定化胶原1型的能力进行了表征。在人牙离体器械根管模型中的菌株的生存进行了比较，通过与亲本或突变体细菌的根管，并确定在12天内的不同时间点恢复的菌落形成单位（CFU）。结果：S. gordonii基因编码的蛋白质具有与Ace相似的保守的胶原结合结构域，命名为cbdA。cbdA缺陷细胞与1型胶原蛋白结合的能力低于亲本细胞（P < .0001）。cbdA缺陷株的遗传互补恢复了胶原结合表型。到第12天，显着更少（P = 0.03）cbdA缺陷比父母的CFU从仪器运河恢复。结论：在S. gordonii。S.与亲本细胞相比，gordonii cbdA缺陷细胞在体外存活，这表明胶原结合蛋白可能有助于口腔链球菌在器械根管内的持久性。（J Endod 2013;39：39-43）
Introduction: The surface-associated collagen-binding protein Ace of Enterococcus faecalis has been implicated as a virulence factor that contributes to bacterial persistence in endodontic infections. The purpose of this study was to determine if proteins with amino acid sequence similarity to Ace found in more abundant oral streptococci could play a similar role in potentially enhancing endodontic infections. Methods: A Streptococcus gordonii gene similar to ace was identified by genome sequence searches in silico. An isogenic derivative of strain DL1 with a disruption in the identified gene was constructed by allelic replacement. Parent and mutant strains were characterized for their ability to bind immobilized collagen type 1 in a microtiter plate-binding assay. Survival of the strains in a human tooth ex vivo-instrumented root canal model was compared by inoculating canals with parental or mutant bacteria and determining the colony-forming units (CFUs) recovered at various time points over a 12-day period. Results: The S. gordonii gene, encoding a protein with a conserved collagen-binding domain similar to that of Ace, was designated cbdA. The cbdA-deficient cells were less able to bind collagen type 1 than parental cells (P < .0001). Genetic complementation of the cbdA-deficient strain restored the collagen-binding phenotype. By day 12, significantly fewer (P = .03) cbdA-deficient than parental CFUs were recovered from instrumented canals. Conclusions: A gene encoding a putative collagen-binding protein was identified in S. gordonii. Fewer S. gordonii cbdA-deficient cells survived ex vivo compared with parental cells, suggesting that collagen-binding proteins may contribute to the persistence of oral streptococci in instrumented root canals. (J Endod 2013;39:39-43)