Streptococcus parasanguis fimbria-associated adhesin Fap1 is required for biofilm formation
Streptococcus parasanguis fimbria-associated adhesin Fap1 is required for biofilm formation
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DOI：
10.1128/iai.69.4.2512-2519.2001
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发表时间：
2001-04-01
影响因子：
3.1
通讯作者：
Fives-Taylor, P
中科院分区：
文献类型：
--
作者：
Froeliger, EH;Fives-Taylor, P
血链球菌是牙齿表面的主要定植菌，因此形成了称为牙菌斑的复杂多物种生物膜的基础。此外，这些细菌可以在天然和人工心脏瓣膜上定植，是心内膜炎的常见原因。在这组生物中，对控制多物种或单物种生物膜发育的分子机制知之甚少。通过体外生物膜形成实验，我们确定(i)副鳗链球菌FW213可以在惰性表面（如聚苯乙烯）上形成生物膜；（ii）环境和营养因素（如葡萄糖）影响副鳗链球菌生物膜的形成。在生物膜试验中检测了FW213的几个等基因突变体。含有fap1基因突变的菌株缺乏生物膜的形成。fap1基因编码一种组装菌毛所需的蛋白质。recA、PepO内肽酶活性或纤维相关蛋白FimA产生缺陷的突变体仍然能够形成生物膜。利用相衬显微镜观察野生型和fap1突变株在塑料盖上的生物膜随时间的变化。野生型FW213附着在表面，形成细胞聚集体，最终形成包含微菌落的致密细胞层。相比之下，fap1突变体细胞很少附着在表面，没有形成细胞聚集或微集落。这些结果表明，FW213的长周膜对固体表面生物膜的形成至关重要。
The sanguis streptococci are primary colonizers of the tooth surface and thus form the foundation for the complex multiple species biofilm known as dental plaque. In addition, these bacteria can colonize native and prosthetic heart valves and are a common cause of endocarditis. Little is known about the molecular mechanisms governing multiple or single species biofilm development within this group of organisms. Using an in vitro assay for biofilm formation, we determined that (i) Streptococcus parasanguis FW213 can form biofilms on inert surfaces such as polystyrene and (ii) environmental and nutritional factors, such as glucose, affect S. parasanguis biofilm formation. Several isogenic mutants of FW213 were tested in the biofilm assay. Strains containing mutations in fap1, a gene encoding a protein required for assembly of fimbriae, were deficient in biofilm formation. Mutants defective in recA, PepO endopeptidase activity, or the production of a fimbriae-associated protein, FimA, were still capable of biofilm formation. Phase-contrast microscopy was used to follow biofilm development by wild-type and fap1 mutant strains on plastic coverslips over time. Wild-type FW213 attached to the surface, formed aggregates of cells, and eventually formed a dense layer of cells that included microcolonies. In contrast, few fap1 mutant cells were observed attached to the surface, and no cell aggregates or microcolonies were formed. These results suggest that the long peritrichous fimbriae of FW213 are critical for the formation of biofilms on solid surfaces.