Evaluation of different iron sources and their influence in biofilm formation by the dental pathogen Actinobacillus actinomycetemcomitans.
Evaluation of different iron sources and their influence in biofilm formation by the dental pathogen Actinobacillus actinomycetemcomitans.
复制标题
评估不同铁源及其对牙科病原体伴放线放线杆菌生物膜形成的影响。
DOI：
10.1099/jmm.0.46844-0
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发表时间：
2007
影响因子：
3
通讯作者：
Actis,LuisA
中科院分区：
文献类型：
--
作者：
Rhodes,EricR;Shoemaker,ChristopherJ;Menke,SharonM;Edelmann,RichardE;Actis,LuisA
伴放线放线杆菌是一种与口腔和口腔外感染相关的病原体，需要铁在限制条件下生长。虽然不能产生铁载体，但这种病原体可以通过与血红素、血红蛋白、乳铁蛋白和转铁蛋白等化合物直接相互作用来获得铁。在这项工作中，不同的能力。放线菌共生菌株结合和利用不同铁源的能力。测试的菌株均不使用血红蛋白、乳铁蛋白或转铁蛋白作为铁的唯一来源。然而，它们都使用FeCl3和血红素作为铁源在螯合条件下。斑点杂交结合试验表明，所有菌株结合乳铁蛋白，血红蛋白和血红素，但不转铁蛋白。插入失活的hmsF，它编码一个预测的细胞包膜蛋白相关的血红素储存蛋白由其他病原体产生，减少血红素和刚果红结合显着，而不影响血红素利用铁源螯合条件下。生物膜测定表明，所有测试菌株附着在塑料上，并在富铁和铁螯合条件下形成生物膜。然而，扫描电子显微镜显示，光滑的菌株比粗糙的菌株形成更简单的生物膜。此外，粗糙的细胞在FeCl3或血红素的存在下孵育导致更多的聚集体和小菌落的形成相比，当细胞生长在合成的铁螯合剂联吡啶的存在下形成的细胞聚集体较少。这些细胞对细胞外铁浓度变化的反应可能反映了这种病原体在人类口腔中遇到的条件下表达的那些。
Actinobacillus actinomycetemcomitans, a pathogen associated with oral and extra-oral infections, requires iron to grow under limiting conditions. Although incapable of producing siderophores, this pathogen could acquire iron by direct interaction with compounds such as haemin, haemoglobin, lactoferrin and transferrin. In this work the ability of differentA. actinomycetemcomitansstrains to bind and use different iron sources was tested. None of the strains tested used haemoglobin, lactoferrin or transferrin as sole sources of iron. However, all of them used FeCl3and haemin as iron sources under chelated conditions. Dot-blot binding assays showed that all strains bind lactoferrin, haemoglobin and haemin, but not transferrin. Insertion inactivation ofhmsF, which encodes a predicted cell-envelope protein related to haemin-storage proteins produced by other pathogens, reduced haemin and Congo red binding drastically without affecting haemin utilization as an iron source under chelated conditions. Biofilm assays showed that all strains tested attached to and formed biofilms on plastic under iron-rich and iron-chelated conditions. However, scanning electron microscopy showed that smooth strains formed simpler biofilms than rough isolates. Furthermore, the incubation of rough cells in the presence of FeCl3or haemin resulted in the formation of more aggregates and microcolonies compared with the fewer cell aggregates formed when cells were grown in the presence of the synthetic iron chelator dipyridyl. These cell responses to changes in extracellular iron concentrations may reflect those that this pathogen expresses under the conditions it encounters in the human oral cavity.