Please use this identifier to cite or link to this item:
Title: Urease activity represents an alternative pathway for Mycobacterium tuberculosis nitrogen metabolism
Authors: Lin, W.
Mathys, V.
Ang, E.L.Y. 
Koh, V.H.Q.
Gómez, J.M.M.
Ang, M.L.T.
Rahim, S.Z.Z.
Tan, M.P.
Pethe, K.
Alonso, S.
Issue Date: Aug-2012
Citation: Lin, W., Mathys, V., Ang, E.L.Y., Koh, V.H.Q., Gómez, J.M.M., Ang, M.L.T., Rahim, S.Z.Z., Tan, M.P., Pethe, K., Alonso, S. (2012-08). Urease activity represents an alternative pathway for Mycobacterium tuberculosis nitrogen metabolism. Infection and Immunity 80 (8) : 2771-2779. ScholarBank@NUS Repository.
Abstract: Urease represents a critical virulence factor for some bacterial species through its alkalizing effect, which helps neutralize the acidic microenvironment of the pathogen. In addition, urease serves as a nitrogen source provider for bacterial growth. Pathogenic mycobacteria express a functional urease, but its role during infection has yet to be characterized. In this study, we constructed a urease-deficient Mycobacterium tuberculosis strain and confirmed the alkalizing effect of the urease activity within the mycobacterium-containing vacuole in resting macrophages but not in the more acidic phagolysosomal compartment of activated macrophages. However, the urease-mediated alkalizing effect did not confer any growth advantage on M. tuberculosis in macrophages, as evidenced by comparable growth profiles for the mutant, wild-type (WT), and complemented strains. In contrast, the urease-deficient mutant exhibited impaired in vitro growth compared to the WT and complemented strains when urea was the sole source of nitrogen. Substantial amounts of ammonia were produced by the WT and complemented strains, but not with the urease-deficient mutant, which represents the actual nitrogen source for mycobacterial growth. However, the ureasedeficient mutant displayed parental colonization profiles in the lungs, spleen, and liver in mice. Together, our data demonstrate a role for the urease activity in M. tuberculosis nitrogen metabolism that could be crucial for the pathogen's survival in nutrientlimited microenvironments where urea is the sole nitrogen source. Our work supports the notion that M. tuberculosis virulence correlates with its unique metabolic versatility and ability to utilize virtually any carbon and nitrogen sources available in its environment. © 2012, American Society for Microbiology.
Source Title: Infection and Immunity
ISSN: 00199567
DOI: 10.1128/IAI.06195-11
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.


checked on Oct 1, 2022


checked on Sep 23, 2022

Page view(s)

checked on Sep 22, 2022

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.