PubMedCrossRef 69. Brodsky IE, Medzhitov R: Targeting of immune signalling networks by bacterial pathogens. Nat Cell Biol 2009,11(5):521–526.PubMedCrossRef 70. Fukano Y, Knowles NG, Usui ML, Underwood RA, Hauch KD, Marshall AJ, Ratner BD, Giachelli C, Carter

WG, Fleckman P, et al.: Characterization of an in vitro model for evaluating the interface between skin and percutaneous biomaterials. Wound Repair Regen 2006,14(4):484–491.PubMedCrossRef 71. Lenz AP, Williamson KS, Pitts B, Stewart PS, Franklin MJ: Localized gene expression in Pseudomonas aeruginosa biofilms. Appl Environ Microbiol 2008,74(14):4463–4471.PubMedCrossRef 72. Sturn A, Quackenbush J, Trajanoski Z: Genesis: cluster analysis of microarray click here data. Bioinformatics 2002,18(1):207–208.PubMedCrossRef 73. Dennis G Jr, Sherman BT, Hosack DA, Yang J, Gao W, Lane HC, Lempicki RA: DAVID: Database for Annotation, Visualization, and Integrated Discovery. Genome Biol 2003,4(5):P3.PubMedCrossRef Competing interests The authors declare that they have no competing interests. Authors’ contributions PRS was responsible PF01367338 for culturing keratinocytes and S. aureus, SDS-PAGE analysis, ELISA assays, MAPK analysis, running TUNEL assays, RNA extractions, and ARS-1620 in vitro drafted the manuscript. KM carried

out microarray sample processing and analysis. GAJ, PF, JEO, and PSS conceived of the study, participated in its design and coordination, and helped to draft the manuscript. All authors read and approved the final manuscript.”
“Background The pathogenic nature of Salmonella enterica has been shaped by the horizontal acquisition of virulence determinants

[1, 2]. In Salmonella enterica serovar Typhimurium (S. Typhimurium), many virulence genes are organized in mobile elements such as pathogenicity islands, prophages, and the Salmonella virulence plasmid [3, 4]. The increased pathogenic capacity conferred PLEK2 by such genes is dependent on their integration into ancestral regulatory networks of the cell, which can be accomplished by regulatory evolution following horizontal gene transfer [5]. The Hha/YmoA family of small nucleoid-associated proteins in Enterobacteriaceae [6] can participate in fine-tuning virulence gene expression in response to environmental cues [6, 7]. For example, YmoA regulates expression of Yop proteins, YadA adhesin, Yst enterotoxin and invasin in Yersinia enterocolitica [7–9]. Hha negatively regulates the α-hemolysin genes hlyCABD in Escherichia coli [10], hilA encoded within Salmonella pathogenicity island 1 (SPI-1) in S. Typhimurium [11] and the locus of enterocyte effacement in enterohemorrhagic E. coli [12]. A third member, YdgT, similarly represses hlyCABD in E. coli [13]. We and others have shown that Hha and YdgT are repressors of the type III secretion system (T3SS) encoded in Salmonella Pathogenicity island 2 (SPI-2), where they provide an important negative regulatory input required for virulence [14–16].