生物谷報道：弗吉尼亞州立大學(Virginia Commonwealth University)研究人員最近破譯出一種人類口腔常見細菌的基因組。
血鏈球菌（Streptococcus sanguinis）是形成牙菌斑的多種微生物之一,，通常對人體無害,，但進入血液（很可能通過口腔微小傷口）后有可能引起細菌性心內(nèi)膜炎（有致死性）,。分析S.sanguinis的基因組有助于更好地了解其生命周期、代謝和入侵宿主,、引起細菌性心內(nèi)膜炎,。Francis Macrina率領的研究小組發(fā)現(xiàn)了許多S.sanguinis細胞表面蛋白，為藥物研發(fā)提供了候選靶標,。
電鏡下的S.sanguinis
研究結(jié)果顯示,，這種革蘭氏陽性菌的基因組是環(huán)狀DNA分子，大約由2 40萬堿基對組成,，比其它已測序鏈球菌的基因組都要大,，多出DNA部分顯然來自于其它細菌，編碼基因賦予S.sanguinis更好應對良好口腔衛(wèi)生環(huán)境的能力。
文章作者Gregory A. Buck 說,，對S.sanguinis基因組測序有助于整體把握這種重要病原體的生物學特征,，為弄清其致病機理開啟了一扇新的大門。文章刊登于4月份Journal of Bacteriology 雜志,。
部分英文原文：
Journal of Bacteriology, April 2007, p. 3166-3175, Vol. 189, No. 8
0021-9193/07/$08.00+0 doi:10.1128/JB.01808-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.
Genome of the Opportunistic Pathogen Streptococcus sanguinis ,
Ping Xu,1,2,3, Joao M. Alves,2,3, Todd Kitten,1,2,3 Arunsri Brown,1, Zhenming Chen,2,3,¶ Luiz S. Ozaki,2,3 Patricio Manque,2,3 Xiuchun Ge,1 Myrna G. Serrano,2,3 Daniela Puiu,2,|| Stephanie Hendricks,3 Yingping Wang,2,3 Michael D. Chaplin,2 Doruk Akan,2, Sehmi Paik,1,3, Darrell L. Peterson,4 Francis L. Macrina,1,2,3* and Gregory A. Buck2,3*
Philips Institute of Oral and Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia 23298-0566,1 Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, Virginia 23284-2030,2 Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, Virginia 23298-0678,3 Department of Biochemistry and Molecular Biophysics, Virginia Commonwealth University, Richmond, Virginia 23298-06144
Received 30 November 2006/ Accepted 29 January 2007
The genome of Streptococcus sanguinis is a circular DNA molecule consisting of 2,388,435 bp and is 177 to 590 kb larger than the other 21 streptococcal genomes that have been sequenced. The G+C content of the S. sanguinis genome is 43.4%, which is considerably higher than the G+C contents of other streptococci. The genome encodes 2,274 predicted proteins, 61 tRNAs, and four rRNA operons. A 70-kb region encoding pathways for vitamin B12 biosynthesis and degradation of ethanolamine and propanediol was apparently acquired by horizontal gene transfer. The gene complement suggests new hypotheses for the pathogenesis and virulence of S. sanguinis and differs from the gene complements of other pathogenic and nonpathogenic streptococci. In particular, S. sanguinis possesses a remarkable abundance of putative surface proteins, which may permit it to be a primary colonizer of the oral cavity and agent of streptococcal endocarditis and infection in neutropenic patients.
* Corresponding author. Mailing address: Center for the Study of Biological Complexity, Virginia Commonwealth University, Richmond, VA 23284-2030. Phone for Francis L. Macrina: (804) 827-2622. Fax: (804) 828-2051. E-mail: [email protected] . Phone for Gregory A. Buck: (804) 828-2318. Fax: (804) 828-1397. E-mail: [email protected]
