Nature 1970, 227:680–685.PubMedCrossRef 51. Tai SS, Yu C, Lee JK: A solute binding protein of selleck products Streptococcus pneumoniae iron transport. FEMS Microbiol Lett 2003,220(2):303–308.PubMedCrossRef 52. Bolotin S, Fuller JD, Bast DJ, Azavedo JCSD: The two-component system sivS/R

regulates virulence in Streptococcus iniae . FEMS Immunol Med Microbiol 2007,51(3):547–554.PubMedCrossRef 53. Homonylo-McGavin MK, Lee SF: Role of the terminus in antigen P1 surface localization in Streptococcus mutans and two related cocci. J Bacteriol 1996,178(3):801–807.PubMed 54. Lei BF, Wei CJ, Tu SC: Action mechanism of antitubercular isoniazid: activation by Mycobacterium tuberculosis KatG, isolation, and characterization of InhA inhibitor. J Biol Chem 2000, 275:2520–2526.PubMedCrossRef 55. Lei BF, Smoot LM, Menning HM, Voyich JM, Kala SV, Deleo FR,

Reid SD, Musser JM: Identification and Characterization of a Novel Heme-Associated Cell Surface Protein Made by Streptococcus pyogenes . Infect Immun 2002,70(8):4494–4500.PubMedCrossRef Authors’ contributions LLZ carried out the molecular genetic studies, participated in the sequence alignment studies, performed the statistical analysis, and drafted the manuscript. JW carried out the function studies and participated in the sequence LY2109761 cost alignment studies. HBF carried out the infection assay. MQX conceived of the study and participated in its design and coordination. AXL participated in the conceived of the study and helped to draft the manuscript. All

authors read and approved the final manuscript.”
“Background Bacillus cereus and the closely related Bacillus thuringiensis are Gram positive bacteria belonging to the B. cereus group, recognized as causative agents of gastrointestinal disease. Three pore-forming toxins appear to be responsible for the diarrhoeal type of food poisoning: Hemolysin BL (Hbl), Non-haemolytic enterotoxin (Nhe), and Cytotoxin K (CytK) [1]. Since B. thuringiensis is only differentiated from B. cereus by the presence of plasmids encoding insecticidal crystal toxins [2], B. cereus and B. thuringiensis show a similar prevalence and expression Forskolin chemical structure of genes encoding these cytotoxins [3, 4]. Hbl and Nhe each consist of three different protein components, named L2, L1, and B, and NheA, NheB and NheC, respectively, while CytK is a single-component toxin [1]. The expression of the B. cereus cytotoxins is positively regulated by a quorum sensing system composed of the CUDC-907 nmr transcriptional activator PlcR and its activating peptide PapR [5]. Expression of Hbl and Nhe is also regulated by the redox-sensitive two-component regulatory system ResDE and the redox regulator Fnr [6, 7], and to a lesser extent the catabolite control protein CcpA [8], demonstrating a link between virulence and the metabolic state of the cell.