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

 Previous Article  |  Next Article 

Infection and Immunity, February 2007, p. 774-780, Vol. 75, No. 2
0019-9567/07/$08.00+0     doi:10.1128/IAI.01244-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Characterization of the Urease Operon of Brucella abortus and Assessment of Its Role in Virulence of the Bacterium{triangledown}

Félix J. Sangari,1 Asunción Seoane,1 María Cruz Rodríguez,1 Jesús Agüero,1,2 and Juan M. García Lobo1*

Departamento de Biología Molecular, Facultad de Medicina, Universidad de Cantabria, c/Cardenal Herrera Oria s/n, 39011 Santander, Spain,1 Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla, Santander, Spain2

Received 4 August 2006/ Returned for modification 18 September 2006/ Accepted 4 November 2006

Most members of the genus Brucella show strong urease activity. However, the role of this enzyme in the pathogenesis of Brucella infections is poorly understood. We isolated several Tn5 insertion mutants deficient in urease activity from Brucella abortus strain 2308. The mutations of most of these mutants mapped to a 5.7-kbp DNA region essential for urease activity. Sequencing of this region, designated ure1, revealed the presence of seven open reading frames corresponding to the urease structural proteins (UreA, UreB, and UreC) and the accessory proteins (UreD, UreE, UreF, and UreG). In addition to the urease genes, another gene (cobT) was identified, and inactivation of this gene affected urease activity in Brucella. Subsequent analysis of the previously described sequences of the genomes of Brucella spp. revealed the presence of a second urease cluster, ure2, in all them. The ure2 locus was apparently inactive in B. abortus 2308. Urease-deficient mutants were used to evaluate the role of urease in Brucella pathogenesis. The urease-producing strains were found to be resistant in vitro to strong acid conditions in the presence of urea, while urease-negative mutants were susceptible to acid treatment. Similarly, the urease-negative mutants were killed more efficiently than the urease-producing strains during transit through the stomach. These results suggested that urease protects brucellae during their passage through the stomach when the bacteria are acquired by the oral route, which is the major route of infection in human brucellosis.

* Corresponding author. Mailing address: Departamento de Biología Molecular, Universidad de Cantabria, C/Cardenal Herrera Oria s/n, 39011 Santander, Spain. Phone: 34-942201948. Fax: 34-942201945. E-mail: jmglobo{at}unican.es.

{triangledown} Published ahead of print on 13 November 2006.

Editor: A. Camilli

Infection and Immunity, February 2007, p. 774-780, Vol. 75, No. 2
0019-9567/07/$08.00+0     doi:10.1128/IAI.01244-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Paixao, T. A., Roux, C. M., den Hartigh, A. B., Sankaran-Walters, S., Dandekar, S., Santos, R. L., Tsolis, R. M. (2009). Establishment of Systemic Brucella melitensis Infection through the Digestive Tract Requires Urease, the Type IV Secretion System, and Lipopolysaccharide O Antigen. Infect. Immun. 77: 4197-4208 [Abstract] [Full Text]  
  • Yu, G.X., Snyder, E.E., Boyle, S.M., Crasta, O.R., Czar, M., Mane, S.P., Purkayastha, A., Sobral, B., Setubal, J.C. (2007). A versatile computational pipeline for bacterial genome annotation improvement and comparative analysis, with Brucella as a use case. Nucleic Acids Res 35: 3953-3962 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»