This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Müller, C. M. Articles by Hacker, J. Search for Related Content PubMed PubMed Citation Articles by Müller, C. M. Articles by Hacker, J.

Role of Histone-Like Proteins H-NS and StpA in Expression of Virulence Determinants of Uropathogenic Escherichia coli

Institut für Molekulare Infektionsbiologie, Universität Würzburg, D-97070 Würzburg, Germany,¹ Institute of Medical Microbiology and Immunology, University of Pécs Medical School, H-7624 Pécs, Hungary,² Department of Molecular Biology, Umeå University, S-90187 Umeå, Sweden³

Received 21 December 2005/ Accepted 12 May 2006

The histone-like protein H-NS is a global regulator in Escherichia coli that has been intensively studied in nonpathogenic strains. However, no comprehensive study on the role of H-NS and its paralogue, StpA, in gene expression in pathogenic E. coli has been carried out so far. Here, we monitored the global effects of H-NS and StpA in a uropathogenic E. coli isolate by using DNA arrays. Expression profiling revealed that more than 500 genes were affected by an hns mutation, whereas no effect of StpA alone was observed. An hns stpA double mutant showed a distinct gene expression pattern that differed in large part from that of the hns single mutant. This suggests a direct interaction between the two paralogues and the existence of distinct regulons of H-NS and an H-NS/StpA heteromeric complex. hns mutation resulted in increased expression of alpha-hemolysin, fimbriae, and iron uptake systems as well as genes involved in stress adaptation. Furthermore, several other putative virulence genes were found to be part of the H-NS regulon. Although the lack of H-NS, either alone or in combination with StpA, has a huge impact on gene expression in pathogenic E. coli strains, its effect on virulence is ambiguous. At a high infection dose, hns mutants trigger more sudden lethality due to their increased acute toxicity in murine urinary tract infection and sepsis models. At a lower infectious dose, however, mutants lacking H-NS are attenuated through their impaired growth rate, which can only partially be compensated for by the higher expression of numerous virulence factors.

This article has been cited by other articles:

• Hernandez-Lucas, I., Gallego-Hernandez, A. L., Encarnacion, S., Fernandez-Mora, M., Martinez-Batallar, A. G., Salgado, H., Oropeza, R., Calva, E. (2008). The LysR-Type Transcriptional Regulator LeuO Controls Expression of Several Genes in Salmonella enterica Serovar Typhi. J. Bacteriol. 190: 1658-1670 [Abstract] [Full Text]  
• Anfora, A. T., Haugen, B. J., Roesch, P., Redford, P., Welch, R. A. (2007). Roles of Serine Accumulation and Catabolism in the Colonization of the Murine Urinary Tract by Escherichia coli CFT073. Infect. Immun. 75: 5298-5304 [Abstract] [Full Text]  
• Lawrenz, M. B., Miller, V. L. (2007). Comparative Analysis of the Regulation of rovA from the Pathogenic Yersiniae. J. Bacteriol. 189: 5963-5975 [Abstract] [Full Text]  
• Torres, A. G., Lopez-Sanchez, G. N., Milflores-Flores, L., Patel, S. D., Rojas-Lopez, M., Martinez de la Pena, C. F., Arenas-Hernandez, M. M. P., Martinez-Laguna, Y. (2007). Ler and H-NS, Regulators Controlling Expression of the Long Polar Fimbriae of Escherichia coli O157:H7. J. Bacteriol. 189: 5916-5928 [Abstract] [Full Text]  
• Navarre, W. W., McClelland, M., Libby, S. J., Fang, F. C. (2007). Silencing of xenogeneic DNA by H-NS--facilitation of lateral gene transfer in bacteria by a defense system that recognizes foreign DNA. Genes Dev. 21: 1456-1471 [Abstract] [Full Text]  
• Haugen, B. J., Pellett, S., Redford, P., Hamilton, H. L., Roesch, P. L., Welch, R. A. (2007). In Vivo Gene Expression Analysis Identifies Genes Required for Enhanced Colonization of the Mouse Urinary Tract by Uropathogenic Escherichia coli Strain CFT073 dsdA. Infect. Immun. 75: 278-289 [Abstract] [Full Text]