Biofilm formation by Moraxella catarrhalis in vitro: roles of the UspA1 adhesin and the Hag hemagglutinin.
Biofilm formation by Moraxella catarrhalis in vitro: roles of the UspA1 adhesin and the Hag hemagglutinin.
复制标题
卡他莫拉菌体外生物膜形成：UspA1 粘附素和 Hag 血凝素的作用。
DOI：
10.1128/iai.74.3.1588-1596.2006
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Hansen,EricJ
中科院分区：
文献类型：
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作者：
Pearson,MelanieM;Laurence,CassieA;Guinn,SarahE;Hansen,EricJ
突变体分析用于鉴定卡他莫拉菌基因产物，该基因产物在涉及24孔组织培养板的基于结晶紫的测定中是生物膜发育所必需的。野生型M.在该系统中，形成最广泛生物膜的卡他菌菌株被证明是转座子诱变的抗性菌株，因此，M.构建了一种既能在体外形成生物膜又能进行转座子诱变的卡他菌株。使用来自生物膜阳性菌株O 46 E的染色体DNA转化生物膜阴性菌株O35 E;鉴定能够形成生物膜的转化体并进行转座子介导的诱变。这些转化体的生物膜阴性突变体被证明在theuspA 1基因中具有转座子插入。核苷酸序列分析表明，生物膜阳性的pET 14含有一个杂合O 46 E-O35 EuspA 1基因，其N-末端155个氨基酸来自O 46 E UspA 1蛋白。转化体T14也显示不能表达Hag蛋白，该蛋白通常从M.粘膜炎细胞将野生型O35 Ehaggene引入T14消除了其形成生物膜的能力。用T14的O 46 E-O35 EuspA 1杂合基因替代O35 E的uspA 1基因，该菌株不形成生物膜。然而，haggene的失活确实允许表达杂合O 46 E-O35 EuspA 1基因产物的菌株O35 E形成生物膜。Hag蛋白被证明对theseM的生物膜形成具有抑制或负面影响。在结晶紫为基础的测定中，
Mutant analysis was used to identifyMoraxella catarrhalisgene products necessary for biofilm development in a crystal violet-based assay involving 24-well tissue culture plates. The wild-typeM. catarrhalisstrains that formed the most extensive biofilms in this system proved to be refractory to transposon mutagenesis, so anM. catarrhalisstrain was constructed that was both able to form biofilms in vitro and amenable to transposon mutagenesis. Chromosomal DNA from the biofilm-positive strain O46E was used to transform the biofilm-negative strain O35E; transformants able to form biofilms were identified and subjected to transposon-mediated mutagenesis. Biofilm-negative mutants of these transformants were shown to have a transposon insertion in theuspA1gene. Nucleotide sequence analysis revealed that the biofilm-positive transformant T14 contained a hybrid O46E-O35EuspA1gene, with the N-terminal 155 amino acids being derived from the O46E UspA1 protein. Transformant T14 was also shown to be unable to express the Hag protein, which normally extends from the surface of theM. catarrhaliscell. Introduction of a wild-type O35Ehaggene into T14 eliminated its ability to form a biofilm. When the hybrid O46E-O35EuspA1gene from T14 was used to replace theuspA1gene of O35E, this transformant strain did not form a biofilm. However, inactivation of thehaggene did allow biofilm formation by strain O35E expressing the hybrid O46E-O35EuspA1gene product. The Hag protein was shown to have an inhibitory or negative effect on biofilm formation by theseM. catarrhalisstrains in the crystal violet-based assay.