Mitis group streptococci express variable pilus islet 2 pili.
Mitis group streptococci express variable pilus islet 2 pili.
复制标题
DOI：
10.1371/journal.pone.0025124
复制
发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Stephens DS
中科院分区：
文献类型：
--
作者：
Zähner D;Gandhi AR;Yi H;Stephens DS
口腔链球菌、微炎链球菌和血链球菌是链球菌Mitis组的成员，也是口腔生物膜、牙菌斑和感染性心内膜炎的病原体，这些疾病过程涉及细菌-细菌和细菌-宿主相互作用。他们的近亲，人类病原体肺炎链球菌使用毛状胰岛2(PI-2)编码的菌毛来促进与真核细胞的粘附。在口腔沙门氏菌、米氏沙门氏菌和血链球菌中发现了编码PI-2菌毛的遗传岛，但在这些物种的其他分离株中没有。PI-2胰岛与肺炎链球菌PI-2胰岛的遗传组织相似，但编码结构毛蛋白PitA和PitB的基因不同。分别鉴定出肺炎链球菌PitA(假基因)和PitB的两个和三个变异体，它们在核苷酸和相应的蛋白质序列上显示出≈20%的差异。PitA和PitB变异的物种独立组合表明以前发生过物种内和物种间的水平基因转移事件。研制的口腔链球菌ATCC35037株PitA和PitB多克隆抗血清表明，口腔链球菌中的PI-2菌毛由PitA和PitB组成。电子显微镜显示，在野生型菌株中，菌毛结构从细菌表面向外辐射700 nm，但在等基因PI-2缺失突变体中没有。抗PitB-抗血清只与含有相同PitB变异体的菌毛反应，而抗PitA抗血清与其他PitA变异体发生交叉反应。电子多位点序列分析表明，所有编码PI-2的口腔链球菌与非PI-2编码的口腔链球菌有密切的亲缘关系和聚集性。这是首次在Mitis群口腔链球菌中鉴定出PI-2菌毛。这些发现为物种内和物种间的水平基因转移提供了一个引人注目的例子。PI-2菌毛的多样性提供了一个可能的关键，可以将菌株特异性的细菌相互作用和/或组织趋向性与Mitis组链球菌的致病特性联系起来。
Streptococcus oralis, Streptococcus mitis, and Streptococcus sanguinis are members of the Mitis group of streptococci and agents of oral biofilm, dental plaque and infective endocarditis, disease processes that involve bacteria-bacteria and bacteria-host interactions. Their close relative, the human pathogen S. pneumoniae uses pilus-islet 2 (PI-2)-encoded pili to facilitate adhesion to eukaryotic cells. PI-2 pilus-encoding genetic islets were identified in S. oralis, S. mitis, and S. sanguinis, but were absent from other isolates of these species. The PI-2 islets resembled the genetic organization of the PI-2 islet of S. pneumoniae, but differed in the genes encoding the structural pilus proteins PitA and PitB. Two and three variants of pitA (a pseudogene in S. pneumoniae) and pitB, respectively, were identified that showed ≈20% difference in nucleotide as well as corresponding protein sequence. Species-independent combinations of pitA and pitB variants indicated prior intra- and interspecies horizontal gene transfer events. Polyclonal antisera developed against PitA and PitB of S. oralis type strain ATCC35037 revealed that PI-2 pili in oral streptococci were composed of PitA and PitB. Electronmicrographs showed pilus structures radiating >700 nm from the bacterial surface in the wild type strain, but not in an isogenic PI-2 deletion mutant. Anti-PitB-antiserum only reacted with pili containing the same PitB variant, whereas anti-PitA antiserum was cross-reactive with the other PitA variant. Electronic multilocus sequence analysis revealed that all PI-2-encoding oral streptococci were closely-related and cluster with non-PI-2-encoding S. oralis strains. This is the first identification of PI-2 pili in Mitis group oral streptococci. The findings provide a striking example of intra- and interspecies horizontal gene transfer. The PI-2 pilus diversity provides a possible key to link strain-specific bacterial interactions and/or tissue tropisms with pathogenic traits in the Mitis group streptococci.
登录
查看更多内容
DOI：
10.1084/jem.106.2.247
发表时间：
1957-08-01
期刊：
The Journal of experimental medicine
影响因子：
--
作者：
BRACCO RM;KRAUSS MR;ROE AS;MACLEOD CM
通讯作者：
MACLEOD CM
DOI：
10.1073/pnas.0908876106
发表时间：
2009-10-06
影响因子：
11.1
作者：
Kankainen, Matti;Paulin, Lars;de Vos, Willem M.
通讯作者：
de Vos, Willem M.
影响因子：
3.2
作者：
Bagnoli, Fabio;Moschioni, Monica;Barocchi, Michele A.
通讯作者：
Barocchi, Michele A.
DOI：
10.1073/pnas.0511017103
发表时间：
2006-02-21
影响因子：
11.1
作者：
Barocchi, MA;Rie, J;Henriques-Normark, B
通讯作者：
Henriques-Normark, B
影响因子：
5.7
作者：
Izore, Thierry;Contreras-Martel, Carlos;Dessen, Andrea
通讯作者：
Dessen, Andrea