猪链球菌2型强毒株05ZYH33二元信号转导系统CiaRH生物学功能研究
|
摘要
猪链球菌2型(Streptococcus suis serotype 2)是一种呈全球分布的人兽共患病病原体。S. suis 2感染不仅可致猪急性败血症、脑膜炎、关节炎、心内膜炎、关节炎及急性死亡,并且可通过伤口和呼吸道等传播途径,导致人的感染发病和死亡,对养猪业及相关从业人员均造成严重威胁。1998年和2005年我国江苏省和四川省分别暴发大规模S. suis 2感染疫情,患者出现链球菌中毒性休克综合征(Streptococcal toxic shock syndrome, STSS),病情凶险,病死率高(62.7%～81.3%),具体致病机制尚不清楚。
二元信号转导系统(two-component signal transduction systems,TCSTS)是广泛存在于细菌中的调控单元,由膜上的组氨酸激酶(histidine kinase, HK)和胞内的反应调节因子(response regulator, RR)两部分组成,在致病菌感染宿主的过程中能调控多种毒力因子的表达以完成其致病过程。本课题组完成了S. suis 2强毒株05ZYH33(分离自STSS病人)的全基因组测序,并对基因组进行注释。结果显示,05ZYH33中存在11个TCSTS和5个孤儿反应调控因子,根据其编码基因所在阅读框的位置,选取其中一个TCSTS,命名为1094HK/1095RR,同源性比对发现1095RR与多种链球菌(肺炎链球菌、化脓链球菌、变形链球菌等)的CiaR氨基酸序列一致性高达80%以上。现已证实在肺炎链球菌中,CiaRH系统对维持细菌的完整性、感受性、毒性等生物活性发挥重要作用,而在猪链球菌中对于CiaRH的研究国内外尚未见报道。
本课题以S. suis 2强毒株05ZYH33为对象,基于同源重组原理筛选获得ciaR基因缺失株,PCR分析及Southern杂交结果证实突变株构建成功。经过反复传代培养,证明敲除株可以稳定生长,壮观霉素抗性表型能够在敲除株中稳定表达。同时在相同条件下观察发现敲除株与野生株的菌落形态和溶血活性均无明显差别。通过绘制生长曲线,发现与野生株相比,敲除株在37℃和40℃其OD600值均明显降低;与40mmol/L过氧化氢共作用15min后涂板计数,突变株存活率明显低于野生株;不同pH值的培养基中培养,发现在pH5.0的酸性环境中突变株OD600值明显低于野生株;收集稳定期(OD600=0.6～0.8)细菌的菌体,置于含0.1% Triton X-100的液体中振荡培养诱导细菌自溶,每间隔1h检测发现突变株OD600值明显低于野生株;野生株与突变株对BALB/c小鼠攻毒(约1×109CFU/只),各10只,两组16h后均死亡9只。综合以上实验结果说明敲除了05ZYH33菌株中的ciaR基因,细菌的生长减慢、繁殖能力减弱,抗氧化应激能力下降,在酸性环境中生长存活能力下降,0.1% Triton X-100诱导下自溶能力增强;但对小鼠的毒力未见明显差别。
生物信息学分析发现CiaR蛋白为DNA结合蛋白,为了明确其调控的具体基因,较全面的诠释该调控系统的生物学功能,首先需要获得纯化的CiaR蛋白。本文通过原核表达系统体外表达了CiaR融合蛋白,将纯化的重组蛋白加免疫佐剂后免疫新西兰兔,获得高效价(1:204800)的兔抗CiaR多克隆抗体血清。Western blot结果显示,该血清可与CiaR重组蛋白发生特异性反应,说明该融合蛋白具有良好的免疫原性。所有上述工作,为进一步开展CiaR的调控机理研究奠定了基础。
Streptococcus suis serotype 2 (S. suis 2) is an important worldwide zoonotic pathogen associated with a wide range of diseases in pigs, including septicaemia, meningitis, pneumonia, endocarditis , arthritis and even sudden death. Occasionally, S. suis 2 can also be transmitted to human beings through respiratory tract or wound contamination,posing the serious threat to the pig-breeding industry and the correlation jobholders. Furthermore, two major emerging infectious disease outbreaks of S. suis 2 in China (one in Jiangsu Province, 1998, and the other in Sichuan Province, 2005), raised considerable international concerns among the public health professionals. A key feature of these two Chinese outbreaks is the prevalence of streptococcal toxic shock syndrome (STSS) manifesting itself as acute high fever, multiple organ failures, short course of disease and high lethality (62.7%~81.3%).But the concrete pathogenesis mechanism still not clear.
Two-component signal transduction systems (TCSTS) composed of a membrane-bound sensor(histidine kinase, HK) and a cytoplasmic response regulator (RR), is an important mechanism used by bacteria to sense and response to environmental stimuli, can regulate many kinds of toxicity factor expression to complete its pathogenesis process. Our joint research group completed a comprehensive study of comparative genomics, decoding the whole genome sequences of the virulent S. suis 2 strain 05ZYH33 ( isolated from Chinese STSS patients), and found that there are 11 TCSTS and 5 orphan response regulators in it.△We focused on a unique TCSTS named 1094HK/1095RR according to its code gene position, discovered that 1095RR and the CiaR amino acid sequence of many kinds of streptococcus (S. pneumonia, S. pyogenes, S.mutants and so on) uniformity reaches as high as above 80%. The system CiaRH of S. pneumonia has been implicated in maintenance of cell integrity, competence and virulence, but the reports of S. suis regarding the CiaRH research have not been emerged.
In this study, the ciaR gene deletion mutant of the wild type strain 05ZYH33 (namely△ciaR) was screened by homologous recombination, PCR analysis and Southern hybridization were used to confirm its correction. After repeatedly serial subcultivation, the spectinomycin resistance phenotype was found to be stable in the△ciaR. Through compared under the same conditions, colony and cell morphology, hemolytic activity were examined but no significant differences between the wild type and mutant strain could be ascertained. The△ciaR mutant was found to grow more slowly than the wild type strain at 37℃and 40℃, as judged by OD600. The sensitivity of cells to peroxide was test by the exposure of aliquots of cultures to 40mM H2O2 for 15min.Viable cells were counted by plating them onto THB agar plates and the results were expressed as percentage of survival. The△ciaR strain was significantly more sensitive to peroxide than the wild type. No obvious differences were observed at different pHs except at pH5.0, in which condition the△ciaR mutant presented growth and survival defects. Put bacterial collection of stationary phases(OD600=0.6～0.8) by centrifuge to 0.1%Triton X-100 to shaking culture, and fast autolysis of the△ciaR was observed by detect OD600 every one hour. Nine of ten mice which infected with the wild type or mutant(1×109CFU/mouse) died at 16hours post-infection. To sum up, lack of the ciaR gene reduces the ability of S. suis 2 05ZYH33 proliferation, tolerance to the oxidative stresses, acid environment and 0.1% Triton X-100 in vitro, but no differences of virulence to mice.
By bioinformatics analysis we knew that the CiaR protein is the DNA-binding protein, in order to identify genes which were regulated, to express the recombinant protein in prokaryotic cells at first. The titer of polyclonal antibody from rabbit serum immunized with recombinant protein reached 1:204800, and the serum could be specifically reacted with the recombinant protein demonstrated by Western blot. All above work lay the foundation for further developing the CiaR regulative mechanism research.
二元信号转导系统(two-component signal transduction systems,TCSTS)是广泛存在于细菌中的调控单元,由膜上的组氨酸激酶(histidine kinase, HK)和胞内的反应调节因子(response regulator, RR)两部分组成,在致病菌感染宿主的过程中能调控多种毒力因子的表达以完成其致病过程。本课题组完成了S. suis 2强毒株05ZYH33(分离自STSS病人)的全基因组测序,并对基因组进行注释。结果显示,05ZYH33中存在11个TCSTS和5个孤儿反应调控因子,根据其编码基因所在阅读框的位置,选取其中一个TCSTS,命名为1094HK/1095RR,同源性比对发现1095RR与多种链球菌(肺炎链球菌、化脓链球菌、变形链球菌等)的CiaR氨基酸序列一致性高达80%以上。现已证实在肺炎链球菌中,CiaRH系统对维持细菌的完整性、感受性、毒性等生物活性发挥重要作用,而在猪链球菌中对于CiaRH的研究国内外尚未见报道。
本课题以S. suis 2强毒株05ZYH33为对象,基于同源重组原理筛选获得ciaR基因缺失株,PCR分析及Southern杂交结果证实突变株构建成功。经过反复传代培养,证明敲除株可以稳定生长,壮观霉素抗性表型能够在敲除株中稳定表达。同时在相同条件下观察发现敲除株与野生株的菌落形态和溶血活性均无明显差别。通过绘制生长曲线,发现与野生株相比,敲除株在37℃和40℃其OD600值均明显降低;与40mmol/L过氧化氢共作用15min后涂板计数,突变株存活率明显低于野生株;不同pH值的培养基中培养,发现在pH5.0的酸性环境中突变株OD600值明显低于野生株;收集稳定期(OD600=0.6～0.8)细菌的菌体,置于含0.1% Triton X-100的液体中振荡培养诱导细菌自溶,每间隔1h检测发现突变株OD600值明显低于野生株;野生株与突变株对BALB/c小鼠攻毒(约1×109CFU/只),各10只,两组16h后均死亡9只。综合以上实验结果说明敲除了05ZYH33菌株中的ciaR基因,细菌的生长减慢、繁殖能力减弱,抗氧化应激能力下降,在酸性环境中生长存活能力下降,0.1% Triton X-100诱导下自溶能力增强;但对小鼠的毒力未见明显差别。
生物信息学分析发现CiaR蛋白为DNA结合蛋白,为了明确其调控的具体基因,较全面的诠释该调控系统的生物学功能,首先需要获得纯化的CiaR蛋白。本文通过原核表达系统体外表达了CiaR融合蛋白,将纯化的重组蛋白加免疫佐剂后免疫新西兰兔,获得高效价(1:204800)的兔抗CiaR多克隆抗体血清。Western blot结果显示,该血清可与CiaR重组蛋白发生特异性反应,说明该融合蛋白具有良好的免疫原性。所有上述工作,为进一步开展CiaR的调控机理研究奠定了基础。
Streptococcus suis serotype 2 (S. suis 2) is an important worldwide zoonotic pathogen associated with a wide range of diseases in pigs, including septicaemia, meningitis, pneumonia, endocarditis , arthritis and even sudden death. Occasionally, S. suis 2 can also be transmitted to human beings through respiratory tract or wound contamination,posing the serious threat to the pig-breeding industry and the correlation jobholders. Furthermore, two major emerging infectious disease outbreaks of S. suis 2 in China (one in Jiangsu Province, 1998, and the other in Sichuan Province, 2005), raised considerable international concerns among the public health professionals. A key feature of these two Chinese outbreaks is the prevalence of streptococcal toxic shock syndrome (STSS) manifesting itself as acute high fever, multiple organ failures, short course of disease and high lethality (62.7%~81.3%).But the concrete pathogenesis mechanism still not clear.
Two-component signal transduction systems (TCSTS) composed of a membrane-bound sensor(histidine kinase, HK) and a cytoplasmic response regulator (RR), is an important mechanism used by bacteria to sense and response to environmental stimuli, can regulate many kinds of toxicity factor expression to complete its pathogenesis process. Our joint research group completed a comprehensive study of comparative genomics, decoding the whole genome sequences of the virulent S. suis 2 strain 05ZYH33 ( isolated from Chinese STSS patients), and found that there are 11 TCSTS and 5 orphan response regulators in it.△We focused on a unique TCSTS named 1094HK/1095RR according to its code gene position, discovered that 1095RR and the CiaR amino acid sequence of many kinds of streptococcus (S. pneumonia, S. pyogenes, S.mutants and so on) uniformity reaches as high as above 80%. The system CiaRH of S. pneumonia has been implicated in maintenance of cell integrity, competence and virulence, but the reports of S. suis regarding the CiaRH research have not been emerged.
In this study, the ciaR gene deletion mutant of the wild type strain 05ZYH33 (namely△ciaR) was screened by homologous recombination, PCR analysis and Southern hybridization were used to confirm its correction. After repeatedly serial subcultivation, the spectinomycin resistance phenotype was found to be stable in the△ciaR. Through compared under the same conditions, colony and cell morphology, hemolytic activity were examined but no significant differences between the wild type and mutant strain could be ascertained. The△ciaR mutant was found to grow more slowly than the wild type strain at 37℃and 40℃, as judged by OD600. The sensitivity of cells to peroxide was test by the exposure of aliquots of cultures to 40mM H2O2 for 15min.Viable cells were counted by plating them onto THB agar plates and the results were expressed as percentage of survival. The△ciaR strain was significantly more sensitive to peroxide than the wild type. No obvious differences were observed at different pHs except at pH5.0, in which condition the△ciaR mutant presented growth and survival defects. Put bacterial collection of stationary phases(OD600=0.6～0.8) by centrifuge to 0.1%Triton X-100 to shaking culture, and fast autolysis of the△ciaR was observed by detect OD600 every one hour. Nine of ten mice which infected with the wild type or mutant(1×109CFU/mouse) died at 16hours post-infection. To sum up, lack of the ciaR gene reduces the ability of S. suis 2 05ZYH33 proliferation, tolerance to the oxidative stresses, acid environment and 0.1% Triton X-100 in vitro, but no differences of virulence to mice.
By bioinformatics analysis we knew that the CiaR protein is the DNA-binding protein, in order to identify genes which were regulated, to express the recombinant protein in prokaryotic cells at first. The titer of polyclonal antibody from rabbit serum immunized with recombinant protein reached 1:204800, and the serum could be specifically reacted with the recombinant protein demonstrated by Western blot. All above work lay the foundation for further developing the CiaR regulative mechanism research.
引文
1. Staats JJ, Feder I, Okwumabua O, et al. Streptococcus suis: past and present. Vet Res Commun. 1997; 21(6): 381-407.
2. Lun ZR, Wang QP, Chen XG, et al. Streptococcus suis: an emerging zoonotic pathogen. Lancet Infect Dis. 2007; 7(3): 201-209.
3. Normile D. Infectious diseases. WHO probes deadliness of China’s pig-borne disease. Science. 2005; 309(5739): 1308-1309.
4. Sriskandan S and Slater JD. Invasive disease and toxic shock due to zoonotic Streptococcus suis: an emerging infection in the East? PLoS Med. 2006; 3(5): e187.
5.唐家琪,朱进,郭恒彬,等.猪链球菌引起人中毒性休克综合征和脑膜脑炎的流行病学调查及病原学研究.第三军医大学学报. 2001; 23(11): 1292-1295.
6. Tang J, Wang C, Feng Y, et al. Streptococcal toxic shock syndrome caused by Streptococcus suis serotype 2. PLoS Med. 2006, 3(5): e151.
7. Basma H, Norrby TA, Guedez Y, et al. Risk factors in the pathogenesis of invasive group A streptococcal infections: role of protective humoral immunity. Infect Immun. 1999; 67(4): 1871-1877.
8. Smith HE, Vecht U, Wissclink HJ, et al. Mutants of Streptococcus suis types l and 2 impaired in expression of muramidase-released protein and extracellular protein induce disease in newborn germfree pigs. Infect Immun. 1996; 64(10): 4409-4412.
9. Lun S, Perez CJ and Connor W. Role of suilysin in pathogenesis of Streptococcus suis capsular serotype 2. Microb Pathog. 2003; 34(1): 27-37.
10. Cotter PA and DiRita VJ. Bacterial virulence gene regulation: an evolutionary perspective. Annu Rev Microbiol. 2000; 54: 519-565.
11. Appleby J L, Parkinson J S and Bourret R B. Signal transduction via themulti-step phosphorelay: not necessarily a road less traveled. Cell, 1996, 86 (6):845-848.
12. Chen C, Tang J, Dong W, et al. A Glimpse of Streptococcal Toxic Shock Syndrome from Comparative Genomics of S. suis 2 Chinese Isolates. PLoS ONE,2007,2: e315.
13. Dagkessamanskaia A, Moscoso M, Henard V, et al. Interconnection of competence, stress and CiaR regulons in Streptococcus pneumoniae: competence triggers stationary phase autolysis of ciaR mutant cells. Mol Microbiol, 2004, 51(4):1071-1086.
14.闻玉梅.病原微生物结构与功能基因组研究现状.中华传染病杂志. 2002; 20(2): 69-70.
15. Abbari K,Bernardi G CpG doublets,CpG islands and Alu repeat elements in long human DNA sequences from different isochores families.Gene,l998,224(12):l23-l28.
16. Galtier N,Piganeau G Mouchiroud D,Duret,L.GC content evolution in mammalian genomes:the biased gene conversion hypothesis.Genetics,200l,l59(2):907-9l1.
17. Rolfe R , Meselson M . The relative homogeneity of microbial DNA.ProcNatlAcadSci U ,1959,45(7):l039-l043.
18. Garcia-Vallve S, Romeu A and Palau J. Horizontal gene transfer in bacterial and archaeal complete genomes. Genome Res. 2000; 10(11): 1719-1725.
19.石秀凡,黄京飞,柳树群等.人类基因同义密码子偏好的特征.生物化学与生物物理进展.2002;29(3):411-414)。
20. Takamatsu D, Osaki M, Sekizaki T. Construction and characterization of Streptococcus suis-Escherichia coli shuttle cloning vectors.Plasmid, 2001,45: 101–113.
21.金涛,吴补领,苏凌云,等.远缘链球菌ftsK基因敲除菌株的构建.牙体牙髓牙周病学杂志.2005;15(5):251-254.
22. Iacono VJ, MacKay BJ, DiRienzo S, et al. Selective antibacterial properties of lysozyme for oral microorganisms. Infect Immun. 1980; 29(2): 623-632.
23.李明,胡福泉,王长军,等.环境条件对猪链球菌2型电转化效率的影响.中国人兽共患病学报, 2007,23(8):760-763.
24. Kimoto H and Taketo A. Efficient electrotransformation system and gene targeting in pyogenic streptococci. Biosci Biotechnol Biochem. 2003; 67(10): 2203-2209.
25. Smith HE, Wisselink HJ, Vecht U, et al. High-efficiency transformation and gene inactivation in Streptococcus suis type 2. Microbiology. 1995;141: 181-188.
26.陈三凤,刘德虎.现代微生物遗传学.化学工业出版社.2003:272-273.
27. Throup JP, Koretke KK, Bryant AP, et al. A genomic analysis of two-component signal transduction in Streptococcus pneumoniae. Mol Microbiol. 2000; 35(3): 566-576.
28. Mani N,Tobin P,Jayaswal RK.Isolation and characterization of antolysis -defective mutants of Staphylococcus aureus created by Tn917-lacZ mutagenesis.J Bacteriol,1993,175(5):1493-1499.
29. Guenzi E, Gasc AM, Sicard MA, et al. A two-component signal-transducing system is involved in competence and penicillin susceptibility in laboratory mutants of Streptococcus pneumoniae. Mol Microbiol.1994, 12(3):505-515.
30. Thorsten M, Manuel H, Dorothea Z, et al. The CiaRH System of Streptococcus pneumoniae Prevents Lysis during Stress Induced by Treatment with Cell Wall Inhibitors and by Mutations in pbp2x Involved in-Lactam Resistance. J Bacteriol, 2006, Mar, p.1959–1968.
31. Yasser Musa Ibrahim. Role of HtrA in the virulence and competence ofStreptococcus pneumonia. Infect. Immun, 2004, June p.3584–3591.
32. Marra, A., J. Asundi, M. Bartilson, et al. Differential fluorescence induction analysis of Streptococcus pneumoniae identifies genes involved in pathogenesis. Infect. Immun, 2002, 70:1422–1433.
33. Sebert, M. E., L. M. Palmer, M. Rosenberg, et al. Microarray-based identification of htrA, a Streptococcus pneumoniae gene that is regulated by the CiaRH two-component system and contributes to nasopharyngeal colonization. Infect. Immun, 2002, 70:4059–4067.
34. Asensio JG, Maia C, Ferrer NL, et al. The virulence associated two-component PhoP-PhoR system controls the biosynthesis of polyketide-derived lipids in Mycobacterium tuberculosis. J Biol Chem. 2006; 281(3): 1313-1316.
35. C.M. Lévesque, R.W. Mair, J.A Perry, et al. Systemic inactivation and phenotypic characterization of two-component systems in expression of Streptococcus mutans virulence properties. Lett Appl Microbiol. 2007 October, 45(4): 398–404.
36. Staats JJ, Plattner BL, Nietfeld J, et al. Use of ribotyping and hemolysin activity to identify highly virulent Streptococcus suis type 2 isolates. J Clin Microbiol. 1998; 36(1):15-19.
37. Norton PM, Rolph C, Ward PN, et al. Epithelial invasion and cell lysis by virulent strains of Streptococcus suis is enhanced by the presence of suilysin. FEMS Immunol Med Microbiol. 1999; 26(1): 25-35.
38. Feder I, Chengappa MM, Fenwick B, et al. Partial characterization of Streptococcus suis type 2 hemolysin. J Clin Microbiol. 1994; 32(5): 1256-1260.
39. Lamy MC, Zouine M, Fert J, et al. CovS/CovR of group B streptococcus: a two-component global regulatory system involved in virulence. Mol Microbiol, 2004; 54(5):1250-1268.
40. Fabret C and Hoch JA. A two-component signal transduction system essential forgrowth of Bacillus subtilis: implications for anti-infective therapy. J Bacteriol. 1998; 180(23): 6375-6383.
41. Quon KC, Yang B, Domian IJ, et al. Negative control of bacterial DNA replication by a cell cycle regulatory protein that binds at the chromosome origin. Proc Natl Acad Sci USA. 1998; 95(1): 120-125.
42. Quon KC, Marczynski GT and Shapiro L. Cell cycle control by an essential bacterial two-component signal transduction protein. Cell. 1996; 84(1): 83-93.
43. Fukuchi K, Kasahara Y, Asai K, et al. The essential two-component regulatory system encoded by yycF and yycG modulates expression of the ftsAZ operon in Bacillus subtilis. Microbiology. 2000; 146(7): 1573-1583.
44. Dubrac S and Msadek T. Identification of genes controlled by the essential YycG/YycF two-component system of Staphylococcus aureus. J Bacteriol. 2004; 186(4): 1175-1181.
45. Kitayama T, Iwabuchi R, Minagawa S, et al. Synthesis of a novel inhibitor against MRSA and VRE: preparation from zerumbone ring opening material showing histidine-kinase inhibition. Bioorg Med Chem Lett. 2007; 17(4): 1098-1101.
46. Mohedano ML, Overweg K, de-la-Fuente A, et al. Evidence that the essential response regulator YycF in Streptococcus pneumoniae modulates expression of fatty acid biosynthesis genes and alters membrane composition. J Bacteriol. 2005; 187(7): 2357-2367.
47. Sang-Joon A, Zezhang T, Robert A. Multilevel Control of Competence Development and Stress Tolerance in Streptococcus mutans UA159. Infect. Immun. Mar.2006,p. 1631–1642
48. Pi?as GE, Cortes PR, Orio AG,et al. Acidic stress induces autolysis by a CSP-independent ComE pathway in Streptococcus pneumoniae. Microbiology. 2008 May;154(Pt 5):1300-8.
49. Dubrac S, Boneca IG, Poupel O, et al. New insights into the WalK/WalR (YycG/YycF) essential signal transduction pathway reveal a major role in controlling cell wall metabolism and biofilm formation in Staphylococcus aureus. J Bacteriol. 2007 Nov; 189(22):8257-69. Epub 2007 Sep 7.
50. Boneca, I. G .The role of peptidoglycan in pathogenesis. Curr. Opin. Microbiol. 2005. 8:46–53.
51. Girardin, S. E., I. G. Boneca, et al. Philpott, and P. J. Sansonetti. Nod2 is a general sensor of peptidoglycan through muramyl dipeptide (MDP) detection. 2003. J. Biol. Chem. 278: 8869–8872.? ?
52. Liang X, Zheng L, Landwehr C, et al. Global regulation of gene expression by ArlRS, a two-component signal transduction regulatory system of Staphylococcus aureus. J Bacteriol . 2005; 187(15): 5486-5492.
53. Bina J, Zhu J, Dziejman M, et al. ToxR regulon of Vibrio cholerae and its expression in vibriosshed by cholera patients. Proc Natl Acad Sci USA. 2003; 100(5): 2801-2806.
54. Navarre WW, Halsey TA, Walthers D, et al. Co-regulation of Salmonella enterica?genes required for virulence and resistance to antimicrobial peptides by SlyA and PhoP/PhoQ. Mol Microbiol. 2005; 56(2): 492-508.
55. Lomas-Lopez R, Cozzone A J, Duclos B. A modified His-tag vector for the production of recombinant protein kinases. Anal Biochem, 2008, 32(2): 167-172.
1. Hoch JA. Two-component and phosphorelay signal transduction. Curr Opin Microbiol, 2000, 3: 165–170.
2. Stock AM, Robinson VL, Goudreau PN. Two-component signal transduction. Annu Rev Biochem, 2000, 69: 183–215.
3. Dutta R, Qin L, Inouye M. Histidine kinases: diversity of domain organization. Mol Microbiol, 1999, 34: 633–640.
4. Throup J P, Koret ke KK, Bryant A P, et al. A genomic analysis of two component signal transduction in Streptococcus pneumonia. Mol Microbiol, 2000, 35 (3): 566-576.
5. Liang X , Zheng L , Landwehr C , et al . Global regulation of gene expression by ArlRS, a two-component signal transduction regulatory system of Staphylococcus aureus. J Bacteriol, 2005, 187 (15): 5486-5492.
6. Lamy MC, Zouine M, Fert J, et al. CovS/ CovR of group B streptococcus: a two-component global regulatory system involved in virulence. Mol Microbiol, 2004, 54( 5 ):1250-1268.
7. Mitchell LS and Tuomanen EI. Molecular analysis of antibiotic tolerance in pneumococci. Med Microbiol. 2002; 292(2): 75-79.
8. Clausen VA, Bae W, Throup J, Burnham MK, Rosenberg M, Wallis NG. Biochemical characterization of the first essential two-component signal transduction system from Staphylococcus aureus and Streptococcus pneumonia . J Mol Microbiol Biotechnol . 2003:5(4):252-260.
9. Yarwood JM, Schlievert PM. Quorum sensing in Staphylococcus infections. J Clin Invest. 2003 Dec;112(11):1620-1625.
10. Nakayama J, Cao Y, Horii T, et al. Gelatinase biosynt hesisactivating pheromone: a peptide lactonet hat mediates aquorum sensing in Enterococcus faecalis. Mol Microbiol, 2001, 41 (1): 145-154.
11. Tang J, Wang C, Feng Y, et al. Streptococcal toxic shock syndrome caused by Streptococcus suis serotype 2. PLoS Med, 2006, 3(5): e151.
12. Chen C, Tang J, Dong W et al. A glimpse of Streptococcal toxic shock syndrome from comparative genomics of S. suis 2 Chinese isolates. PLoS ONE, 2007, 2(3): e315.
13. de Greeff A, Buys H, van Alphen L, et al. Response regulator important in pathogenesis of Streptococcus suis serotype 2. Microb Pathog, 2002, 33(4): 185-192.
14. Smith HE, Buijs H, de Vries R, et al. Environmentally regulated genes ofStreptococcus suis: identification by the use of iron-restricted conditions in vitro and by experimental infection of piglets. Microbiol, 2001, 147: 271-80.
15. Lukat GS, Stock AM, Stock JB. Divalent metal ion binding to the CheY protein and its significance to phosphotransfer in bacterial chemotaxis. Biochemistry, 1990, 29: 5436-5442.
16. Lange R, Wagner C, de Saizieu A, et al. Domain organization and molecular characterization of 13 two-component systems identified by genome sequencing of Streptococcus pneumoniae. Gene, 1999, 237: 223-34.
17. Li M, Wang C, Feng Y, et al. SalK/SalR, a two-component signal transduction system, is essential for full virulence of highly invasive Streptococcus suis serotype 2. PLoS ONE, 2008, 3(5): e2080.
18. Parkinson JS. Signal transduction schemes of bacteria. Cell, 1993, 73: 857-871.
19. Graham MR, Smoot LM, Migliaccio CA, et al. Virulence control in group A Streptococcus by a two-component gene regulatory system: global expression profiling and in vivo infection modeling. Proc. Natl. Acad. Sci. USA, 2002, 99: 13855–13860.
20. Heath A, DiRita, VJ, Barg NL, et al. A two-component regulatory system, CsrR-CsrS, represses expression of three Streptococcus pyogenes virulence factors, hyaluronic acid capsule, streptolysin S, and pyrogenic exotoxin B. Infect Immun, 1999, 67: 5298–5305.
21. Dalton TL, Scott JR. CovS inactivates CovR and is required for growth under conditions of general stress in Streptococcus pyogenes. J. Bacteriol, 2004, 186: 3928-3937.
22. Roberts SA, Churchward GG, Scott JR. Unraveling the regulatory network in Streptococcus pyogenes: the global response regulator CovR represses rivR directly. J Bacteriol, 2007, 189(4): 1459-1463.
23. Rajagopal L, Vo A, Rubens CE, et al. Regulation of cytotoxin expression by converging eukaryotic-type and two-component signaling mechanisms in Streptococcus agalactiae. Mol. Microbiol, 2006, 62 (4): 941–957.
24. Lamy MC, Zouine M, Massimo JF, et al. CovS/CovR of group B streptococcus: a two-component global regulatory system involved in virulence. Mol. Microbiol,2004, 54(5): 1250–1268.
25. Jiang SM, Ishmael N, Hotopp JD, et al. Variation in the group B Streptococcus CsrRS regulon and effects on pathogenicity. J Bacteriol, 2008, 190(6): 1956-1965.
26. Jiang SM, Cieslewicz MJ, Wessels MR, et al. Regulation of virulence by a two-component system in group B streptococcus. J Bacteriol, 2005, 187(3): 1105-1113.
27. Ulijasz AT, Andes DR, Glasner JD, et al. Regulation of iron transport in Streptococcus pneumoniae by RitR, an orphan response regulator. J Bacteriol, 2004: 8123–8136.
28. Chong P, Drake L, Biswas I. Modulation of covR expression in Streptococcus mutans UA159. J Bacteriol. 2008 Jul;190(13):4478-88.
29. Pan X, Ge J, Li M, et al. The Orphan Response Regulator CovR: a Globally Negative Modulator of Virulence in Streptococcus suis Serotype 2. J Bacteriol, 2009.
30. Fuqua C, Winans SC, Greenberg EP. Census and consensus in bacterial ecosystems: the LuxR-LuxI family of quorum-sensing transcriptional regulators. Annu Rev Microbiol, 1996, 50: 727-751
31. Nealson KH, Platt T, Hastings JW. Cellular control of the synthesis and activity of the bacterial luminescent system. J Bacteriol, 1970, 104: 313-322.
32. de Kievit TR, Iglewski BH. Bacterial quorum sensing in pathogenic relationships. Infect Immun, 2000, 68: 4839-4849.
33. Meijler MM, Hom LG, Janda KD, et al. Synthesis and biological validation of a ubiquitous quorum-sensing molecule. Angew Chem Int Ed Engl, 2004, 43: 2106–2108.
34. Hall-Stoodley L, Costerton JW, Stoodley P. Bacterial biofilms: from the natural environment to infectious diseases. Nat Rev Microbiol, 2004, 2: 95–108.
35. Muh U, Hare BJ, Greenberg EP, et al. A structurally unrelated mimic of a Pseudomonas aeruginosa acyl-homoserine lactone quorum-sensing signal. Proc Natl Acad Sci USA, 2006, 103: 16948–16952.
36. Guenzi, E., A. M. Gasc, M. A. Sicard, et al. A two-component signal transducingsystem is involved in competence and penicillin susceptibility in laboratory mutants of Streptococcus pneumoniae. Mol. Microbiol. 1994. 12: 505–515.
37. Sebert ME, Patel KP, Plotnick M, et al. Pneumococcal HtrA protease mediates inhibition of competence by the CiaRH two-component signaling system. J Bacteriol, 2005, 187(12):3969–3979.
38. Mascher T, Heintz M, Hakenbeck R, et al. The CiaRH system of Streptococcus pneumoniae prevents lysis during stress induced by treatment with cell wall inhibitors and by mutations in pbp2x involved in beta-lactam resistance. J Bacteriol, 2006, 188(5): 1959-68.
39. Halfmann A, Kovács M, Hakenbeck R, et al. Identification of the genes directly controlled by the response regulator CiaR in Streptococcus pneumoniae: five out of 15 promoters drive expression of small noncoding RNAs. Mol Microbiol, 2007, 66(1):110-126.
40. Ahn SJ, Wen ZT, Burne RA. Multilevel control of competence development and stress tolerance in Streptococcus mutans UA159. Infect Immun, 2006, 74(3): 1631-42.
41. Qi F, Merritt J, Shi W, et al. Inactivation of the ciaH gene in Streptococcus mutans diminishes mutacin production and competence development, alters sucrose-dependent biofilm formation, and reduces stress tolerance. Infect Immun, 2004, 72: 4895-4899.
42. Mohedano ML, Overweg K, Wells JM, et al. Evidence that the essential response regulator YycF in Streptococcus pneumoniae modulates expression of fatty acid biosynthesis genes and alters membrane composition. J Bacteriol, 2005, 187(7):2357–2367.
43. Qin ZQ, Zhang J, Di Qu, et al. Structure-based discovery of inhibitors of the YycG histidine kinase: New chemical leads to combat Staphylococcus epidermidis infections. BMC Microbiology, 2006, 6: 96.
44. Fraimow H, Knob C, Patel R. Putative VanRS-like two-component regulatory system associated with the inducible glycopeptide resistance cluster of Paenibacillus popilliae. Antimicrob Agents Chemother, 2005, 49(7): 2625-2633.
45. van der Meer JR, Polman J, De Vos WM, et al. Characterization of theLactococcus lactis Nisin A operon genes nisP, encoding a subtilisin-like serine protease involved in precursor processing, and nisR, encoding a regulatory protein involved in Nisin biosynthesis. J Bacteriol, 1993, 175(9):2578-2588.
2. Lun ZR, Wang QP, Chen XG, et al. Streptococcus suis: an emerging zoonotic pathogen. Lancet Infect Dis. 2007; 7(3): 201-209.
3. Normile D. Infectious diseases. WHO probes deadliness of China’s pig-borne disease. Science. 2005; 309(5739): 1308-1309.
4. Sriskandan S and Slater JD. Invasive disease and toxic shock due to zoonotic Streptococcus suis: an emerging infection in the East? PLoS Med. 2006; 3(5): e187.
5.唐家琪,朱进,郭恒彬,等.猪链球菌引起人中毒性休克综合征和脑膜脑炎的流行病学调查及病原学研究.第三军医大学学报. 2001; 23(11): 1292-1295.
6. Tang J, Wang C, Feng Y, et al. Streptococcal toxic shock syndrome caused by Streptococcus suis serotype 2. PLoS Med. 2006, 3(5): e151.
7. Basma H, Norrby TA, Guedez Y, et al. Risk factors in the pathogenesis of invasive group A streptococcal infections: role of protective humoral immunity. Infect Immun. 1999; 67(4): 1871-1877.
8. Smith HE, Vecht U, Wissclink HJ, et al. Mutants of Streptococcus suis types l and 2 impaired in expression of muramidase-released protein and extracellular protein induce disease in newborn germfree pigs. Infect Immun. 1996; 64(10): 4409-4412.
9. Lun S, Perez CJ and Connor W. Role of suilysin in pathogenesis of Streptococcus suis capsular serotype 2. Microb Pathog. 2003; 34(1): 27-37.
10. Cotter PA and DiRita VJ. Bacterial virulence gene regulation: an evolutionary perspective. Annu Rev Microbiol. 2000; 54: 519-565.
11. Appleby J L, Parkinson J S and Bourret R B. Signal transduction via themulti-step phosphorelay: not necessarily a road less traveled. Cell, 1996, 86 (6):845-848.
12. Chen C, Tang J, Dong W, et al. A Glimpse of Streptococcal Toxic Shock Syndrome from Comparative Genomics of S. suis 2 Chinese Isolates. PLoS ONE,2007,2: e315.
13. Dagkessamanskaia A, Moscoso M, Henard V, et al. Interconnection of competence, stress and CiaR regulons in Streptococcus pneumoniae: competence triggers stationary phase autolysis of ciaR mutant cells. Mol Microbiol, 2004, 51(4):1071-1086.
14.闻玉梅.病原微生物结构与功能基因组研究现状.中华传染病杂志. 2002; 20(2): 69-70.
15. Abbari K,Bernardi G CpG doublets,CpG islands and Alu repeat elements in long human DNA sequences from different isochores families.Gene,l998,224(12):l23-l28.
16. Galtier N,Piganeau G Mouchiroud D,Duret,L.GC content evolution in mammalian genomes:the biased gene conversion hypothesis.Genetics,200l,l59(2):907-9l1.
17. Rolfe R , Meselson M . The relative homogeneity of microbial DNA.ProcNatlAcadSci U ,1959,45(7):l039-l043.
18. Garcia-Vallve S, Romeu A and Palau J. Horizontal gene transfer in bacterial and archaeal complete genomes. Genome Res. 2000; 10(11): 1719-1725.
19.石秀凡,黄京飞,柳树群等.人类基因同义密码子偏好的特征.生物化学与生物物理进展.2002;29(3):411-414)。
20. Takamatsu D, Osaki M, Sekizaki T. Construction and characterization of Streptococcus suis-Escherichia coli shuttle cloning vectors.Plasmid, 2001,45: 101–113.
21.金涛,吴补领,苏凌云,等.远缘链球菌ftsK基因敲除菌株的构建.牙体牙髓牙周病学杂志.2005;15(5):251-254.
22. Iacono VJ, MacKay BJ, DiRienzo S, et al. Selective antibacterial properties of lysozyme for oral microorganisms. Infect Immun. 1980; 29(2): 623-632.
23.李明,胡福泉,王长军,等.环境条件对猪链球菌2型电转化效率的影响.中国人兽共患病学报, 2007,23(8):760-763.
24. Kimoto H and Taketo A. Efficient electrotransformation system and gene targeting in pyogenic streptococci. Biosci Biotechnol Biochem. 2003; 67(10): 2203-2209.
25. Smith HE, Wisselink HJ, Vecht U, et al. High-efficiency transformation and gene inactivation in Streptococcus suis type 2. Microbiology. 1995;141: 181-188.
26.陈三凤,刘德虎.现代微生物遗传学.化学工业出版社.2003:272-273.
27. Throup JP, Koretke KK, Bryant AP, et al. A genomic analysis of two-component signal transduction in Streptococcus pneumoniae. Mol Microbiol. 2000; 35(3): 566-576.
28. Mani N,Tobin P,Jayaswal RK.Isolation and characterization of antolysis -defective mutants of Staphylococcus aureus created by Tn917-lacZ mutagenesis.J Bacteriol,1993,175(5):1493-1499.
29. Guenzi E, Gasc AM, Sicard MA, et al. A two-component signal-transducing system is involved in competence and penicillin susceptibility in laboratory mutants of Streptococcus pneumoniae. Mol Microbiol.1994, 12(3):505-515.
30. Thorsten M, Manuel H, Dorothea Z, et al. The CiaRH System of Streptococcus pneumoniae Prevents Lysis during Stress Induced by Treatment with Cell Wall Inhibitors and by Mutations in pbp2x Involved in-Lactam Resistance. J Bacteriol, 2006, Mar, p.1959–1968.
31. Yasser Musa Ibrahim. Role of HtrA in the virulence and competence ofStreptococcus pneumonia. Infect. Immun, 2004, June p.3584–3591.
32. Marra, A., J. Asundi, M. Bartilson, et al. Differential fluorescence induction analysis of Streptococcus pneumoniae identifies genes involved in pathogenesis. Infect. Immun, 2002, 70:1422–1433.
33. Sebert, M. E., L. M. Palmer, M. Rosenberg, et al. Microarray-based identification of htrA, a Streptococcus pneumoniae gene that is regulated by the CiaRH two-component system and contributes to nasopharyngeal colonization. Infect. Immun, 2002, 70:4059–4067.
34. Asensio JG, Maia C, Ferrer NL, et al. The virulence associated two-component PhoP-PhoR system controls the biosynthesis of polyketide-derived lipids in Mycobacterium tuberculosis. J Biol Chem. 2006; 281(3): 1313-1316.
35. C.M. Lévesque, R.W. Mair, J.A Perry, et al. Systemic inactivation and phenotypic characterization of two-component systems in expression of Streptococcus mutans virulence properties. Lett Appl Microbiol. 2007 October, 45(4): 398–404.
36. Staats JJ, Plattner BL, Nietfeld J, et al. Use of ribotyping and hemolysin activity to identify highly virulent Streptococcus suis type 2 isolates. J Clin Microbiol. 1998; 36(1):15-19.
37. Norton PM, Rolph C, Ward PN, et al. Epithelial invasion and cell lysis by virulent strains of Streptococcus suis is enhanced by the presence of suilysin. FEMS Immunol Med Microbiol. 1999; 26(1): 25-35.
38. Feder I, Chengappa MM, Fenwick B, et al. Partial characterization of Streptococcus suis type 2 hemolysin. J Clin Microbiol. 1994; 32(5): 1256-1260.
39. Lamy MC, Zouine M, Fert J, et al. CovS/CovR of group B streptococcus: a two-component global regulatory system involved in virulence. Mol Microbiol, 2004; 54(5):1250-1268.
40. Fabret C and Hoch JA. A two-component signal transduction system essential forgrowth of Bacillus subtilis: implications for anti-infective therapy. J Bacteriol. 1998; 180(23): 6375-6383.
41. Quon KC, Yang B, Domian IJ, et al. Negative control of bacterial DNA replication by a cell cycle regulatory protein that binds at the chromosome origin. Proc Natl Acad Sci USA. 1998; 95(1): 120-125.
42. Quon KC, Marczynski GT and Shapiro L. Cell cycle control by an essential bacterial two-component signal transduction protein. Cell. 1996; 84(1): 83-93.
43. Fukuchi K, Kasahara Y, Asai K, et al. The essential two-component regulatory system encoded by yycF and yycG modulates expression of the ftsAZ operon in Bacillus subtilis. Microbiology. 2000; 146(7): 1573-1583.
44. Dubrac S and Msadek T. Identification of genes controlled by the essential YycG/YycF two-component system of Staphylococcus aureus. J Bacteriol. 2004; 186(4): 1175-1181.
45. Kitayama T, Iwabuchi R, Minagawa S, et al. Synthesis of a novel inhibitor against MRSA and VRE: preparation from zerumbone ring opening material showing histidine-kinase inhibition. Bioorg Med Chem Lett. 2007; 17(4): 1098-1101.
46. Mohedano ML, Overweg K, de-la-Fuente A, et al. Evidence that the essential response regulator YycF in Streptococcus pneumoniae modulates expression of fatty acid biosynthesis genes and alters membrane composition. J Bacteriol. 2005; 187(7): 2357-2367.
47. Sang-Joon A, Zezhang T, Robert A. Multilevel Control of Competence Development and Stress Tolerance in Streptococcus mutans UA159. Infect. Immun. Mar.2006,p. 1631–1642
48. Pi?as GE, Cortes PR, Orio AG,et al. Acidic stress induces autolysis by a CSP-independent ComE pathway in Streptococcus pneumoniae. Microbiology. 2008 May;154(Pt 5):1300-8.
49. Dubrac S, Boneca IG, Poupel O, et al. New insights into the WalK/WalR (YycG/YycF) essential signal transduction pathway reveal a major role in controlling cell wall metabolism and biofilm formation in Staphylococcus aureus. J Bacteriol. 2007 Nov; 189(22):8257-69. Epub 2007 Sep 7.
50. Boneca, I. G .The role of peptidoglycan in pathogenesis. Curr. Opin. Microbiol. 2005. 8:46–53.
51. Girardin, S. E., I. G. Boneca, et al. Philpott, and P. J. Sansonetti. Nod2 is a general sensor of peptidoglycan through muramyl dipeptide (MDP) detection. 2003. J. Biol. Chem. 278: 8869–8872.? ?
52. Liang X, Zheng L, Landwehr C, et al. Global regulation of gene expression by ArlRS, a two-component signal transduction regulatory system of Staphylococcus aureus. J Bacteriol . 2005; 187(15): 5486-5492.
53. Bina J, Zhu J, Dziejman M, et al. ToxR regulon of Vibrio cholerae and its expression in vibriosshed by cholera patients. Proc Natl Acad Sci USA. 2003; 100(5): 2801-2806.
54. Navarre WW, Halsey TA, Walthers D, et al. Co-regulation of Salmonella enterica?genes required for virulence and resistance to antimicrobial peptides by SlyA and PhoP/PhoQ. Mol Microbiol. 2005; 56(2): 492-508.
55. Lomas-Lopez R, Cozzone A J, Duclos B. A modified His-tag vector for the production of recombinant protein kinases. Anal Biochem, 2008, 32(2): 167-172.
1. Hoch JA. Two-component and phosphorelay signal transduction. Curr Opin Microbiol, 2000, 3: 165–170.
2. Stock AM, Robinson VL, Goudreau PN. Two-component signal transduction. Annu Rev Biochem, 2000, 69: 183–215.
3. Dutta R, Qin L, Inouye M. Histidine kinases: diversity of domain organization. Mol Microbiol, 1999, 34: 633–640.
4. Throup J P, Koret ke KK, Bryant A P, et al. A genomic analysis of two component signal transduction in Streptococcus pneumonia. Mol Microbiol, 2000, 35 (3): 566-576.
5. Liang X , Zheng L , Landwehr C , et al . Global regulation of gene expression by ArlRS, a two-component signal transduction regulatory system of Staphylococcus aureus. J Bacteriol, 2005, 187 (15): 5486-5492.
6. Lamy MC, Zouine M, Fert J, et al. CovS/ CovR of group B streptococcus: a two-component global regulatory system involved in virulence. Mol Microbiol, 2004, 54( 5 ):1250-1268.
7. Mitchell LS and Tuomanen EI. Molecular analysis of antibiotic tolerance in pneumococci. Med Microbiol. 2002; 292(2): 75-79.
8. Clausen VA, Bae W, Throup J, Burnham MK, Rosenberg M, Wallis NG. Biochemical characterization of the first essential two-component signal transduction system from Staphylococcus aureus and Streptococcus pneumonia . J Mol Microbiol Biotechnol . 2003:5(4):252-260.
9. Yarwood JM, Schlievert PM. Quorum sensing in Staphylococcus infections. J Clin Invest. 2003 Dec;112(11):1620-1625.
10. Nakayama J, Cao Y, Horii T, et al. Gelatinase biosynt hesisactivating pheromone: a peptide lactonet hat mediates aquorum sensing in Enterococcus faecalis. Mol Microbiol, 2001, 41 (1): 145-154.
11. Tang J, Wang C, Feng Y, et al. Streptococcal toxic shock syndrome caused by Streptococcus suis serotype 2. PLoS Med, 2006, 3(5): e151.
12. Chen C, Tang J, Dong W et al. A glimpse of Streptococcal toxic shock syndrome from comparative genomics of S. suis 2 Chinese isolates. PLoS ONE, 2007, 2(3): e315.
13. de Greeff A, Buys H, van Alphen L, et al. Response regulator important in pathogenesis of Streptococcus suis serotype 2. Microb Pathog, 2002, 33(4): 185-192.
14. Smith HE, Buijs H, de Vries R, et al. Environmentally regulated genes ofStreptococcus suis: identification by the use of iron-restricted conditions in vitro and by experimental infection of piglets. Microbiol, 2001, 147: 271-80.
15. Lukat GS, Stock AM, Stock JB. Divalent metal ion binding to the CheY protein and its significance to phosphotransfer in bacterial chemotaxis. Biochemistry, 1990, 29: 5436-5442.
16. Lange R, Wagner C, de Saizieu A, et al. Domain organization and molecular characterization of 13 two-component systems identified by genome sequencing of Streptococcus pneumoniae. Gene, 1999, 237: 223-34.
17. Li M, Wang C, Feng Y, et al. SalK/SalR, a two-component signal transduction system, is essential for full virulence of highly invasive Streptococcus suis serotype 2. PLoS ONE, 2008, 3(5): e2080.
18. Parkinson JS. Signal transduction schemes of bacteria. Cell, 1993, 73: 857-871.
19. Graham MR, Smoot LM, Migliaccio CA, et al. Virulence control in group A Streptococcus by a two-component gene regulatory system: global expression profiling and in vivo infection modeling. Proc. Natl. Acad. Sci. USA, 2002, 99: 13855–13860.
20. Heath A, DiRita, VJ, Barg NL, et al. A two-component regulatory system, CsrR-CsrS, represses expression of three Streptococcus pyogenes virulence factors, hyaluronic acid capsule, streptolysin S, and pyrogenic exotoxin B. Infect Immun, 1999, 67: 5298–5305.
21. Dalton TL, Scott JR. CovS inactivates CovR and is required for growth under conditions of general stress in Streptococcus pyogenes. J. Bacteriol, 2004, 186: 3928-3937.
22. Roberts SA, Churchward GG, Scott JR. Unraveling the regulatory network in Streptococcus pyogenes: the global response regulator CovR represses rivR directly. J Bacteriol, 2007, 189(4): 1459-1463.
23. Rajagopal L, Vo A, Rubens CE, et al. Regulation of cytotoxin expression by converging eukaryotic-type and two-component signaling mechanisms in Streptococcus agalactiae. Mol. Microbiol, 2006, 62 (4): 941–957.
24. Lamy MC, Zouine M, Massimo JF, et al. CovS/CovR of group B streptococcus: a two-component global regulatory system involved in virulence. Mol. Microbiol,2004, 54(5): 1250–1268.
25. Jiang SM, Ishmael N, Hotopp JD, et al. Variation in the group B Streptococcus CsrRS regulon and effects on pathogenicity. J Bacteriol, 2008, 190(6): 1956-1965.
26. Jiang SM, Cieslewicz MJ, Wessels MR, et al. Regulation of virulence by a two-component system in group B streptococcus. J Bacteriol, 2005, 187(3): 1105-1113.
27. Ulijasz AT, Andes DR, Glasner JD, et al. Regulation of iron transport in Streptococcus pneumoniae by RitR, an orphan response regulator. J Bacteriol, 2004: 8123–8136.
28. Chong P, Drake L, Biswas I. Modulation of covR expression in Streptococcus mutans UA159. J Bacteriol. 2008 Jul;190(13):4478-88.
29. Pan X, Ge J, Li M, et al. The Orphan Response Regulator CovR: a Globally Negative Modulator of Virulence in Streptococcus suis Serotype 2. J Bacteriol, 2009.
30. Fuqua C, Winans SC, Greenberg EP. Census and consensus in bacterial ecosystems: the LuxR-LuxI family of quorum-sensing transcriptional regulators. Annu Rev Microbiol, 1996, 50: 727-751
31. Nealson KH, Platt T, Hastings JW. Cellular control of the synthesis and activity of the bacterial luminescent system. J Bacteriol, 1970, 104: 313-322.
32. de Kievit TR, Iglewski BH. Bacterial quorum sensing in pathogenic relationships. Infect Immun, 2000, 68: 4839-4849.
33. Meijler MM, Hom LG, Janda KD, et al. Synthesis and biological validation of a ubiquitous quorum-sensing molecule. Angew Chem Int Ed Engl, 2004, 43: 2106–2108.
34. Hall-Stoodley L, Costerton JW, Stoodley P. Bacterial biofilms: from the natural environment to infectious diseases. Nat Rev Microbiol, 2004, 2: 95–108.
35. Muh U, Hare BJ, Greenberg EP, et al. A structurally unrelated mimic of a Pseudomonas aeruginosa acyl-homoserine lactone quorum-sensing signal. Proc Natl Acad Sci USA, 2006, 103: 16948–16952.
36. Guenzi, E., A. M. Gasc, M. A. Sicard, et al. A two-component signal transducingsystem is involved in competence and penicillin susceptibility in laboratory mutants of Streptococcus pneumoniae. Mol. Microbiol. 1994. 12: 505–515.
37. Sebert ME, Patel KP, Plotnick M, et al. Pneumococcal HtrA protease mediates inhibition of competence by the CiaRH two-component signaling system. J Bacteriol, 2005, 187(12):3969–3979.
38. Mascher T, Heintz M, Hakenbeck R, et al. The CiaRH system of Streptococcus pneumoniae prevents lysis during stress induced by treatment with cell wall inhibitors and by mutations in pbp2x involved in beta-lactam resistance. J Bacteriol, 2006, 188(5): 1959-68.
39. Halfmann A, Kovács M, Hakenbeck R, et al. Identification of the genes directly controlled by the response regulator CiaR in Streptococcus pneumoniae: five out of 15 promoters drive expression of small noncoding RNAs. Mol Microbiol, 2007, 66(1):110-126.
40. Ahn SJ, Wen ZT, Burne RA. Multilevel control of competence development and stress tolerance in Streptococcus mutans UA159. Infect Immun, 2006, 74(3): 1631-42.
41. Qi F, Merritt J, Shi W, et al. Inactivation of the ciaH gene in Streptococcus mutans diminishes mutacin production and competence development, alters sucrose-dependent biofilm formation, and reduces stress tolerance. Infect Immun, 2004, 72: 4895-4899.
42. Mohedano ML, Overweg K, Wells JM, et al. Evidence that the essential response regulator YycF in Streptococcus pneumoniae modulates expression of fatty acid biosynthesis genes and alters membrane composition. J Bacteriol, 2005, 187(7):2357–2367.
43. Qin ZQ, Zhang J, Di Qu, et al. Structure-based discovery of inhibitors of the YycG histidine kinase: New chemical leads to combat Staphylococcus epidermidis infections. BMC Microbiology, 2006, 6: 96.
44. Fraimow H, Knob C, Patel R. Putative VanRS-like two-component regulatory system associated with the inducible glycopeptide resistance cluster of Paenibacillus popilliae. Antimicrob Agents Chemother, 2005, 49(7): 2625-2633.
45. van der Meer JR, Polman J, De Vos WM, et al. Characterization of theLactococcus lactis Nisin A operon genes nisP, encoding a subtilisin-like serine protease involved in precursor processing, and nisR, encoding a regulatory protein involved in Nisin biosynthesis. J Bacteriol, 1993, 175(9):2578-2588.