Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2009 Aug;191(15):4714-21.
doi: 10.1128/JB.00305-09. Epub 2009 May 22.

Acid resistance in Mycobacterium tuberculosis

Omar H Vandal  1 , Carl F Nathan, Sabine Ehrt
Affiliations
Review

Acid resistance in Mycobacterium tuberculosis

Omar H Vandal et al. J Bacteriol. 2009 Aug.
No abstract available

PubMed Disclaimer

Figures

FIG. 1.
FIG. 1.
M. tuberculosis inside the macrophage. In resting macrophages, M. tuberculosis impairs phagosome maturation and resides in a mildly acidic compartment. Activation with IFN-γ results in phagosome maturation and phagosome-lysosome fusion. This exposes the bacteria to host-derived stress including protons from the vacuolar ATPase, RNI and ROI, free fatty acids, ubiquitin-derived peptides, and lysosomal hydrolases. M. tuberculosis resists acidification with the help of the Rv3671c-encoded membrane-bound serine protease, the putative magnesium transporter MgtC, and the pore-forming M. tuberculosis outer membrane protein (OmpATb). The exact mechanisms by which these proteins confer acid resistance remain to be identified.
FIG. 2.
FIG. 2.
(A) Impact of pH and cell density on survival of M. tuberculosis. Cultures were plated after incubation for 6 days at pH 5.5 (squares), pH 5.0 (triangles), or pH 4.5 (circles) at input densities ranging from 2.5 × 108 to 1 × 106 CFU/ml. Data are means ± standard deviations of triplicate cultures and represent two independent experiments. For the experimental protocol and a description of the media, please see reference . In some cases, error bars are too small to visualize. (B) Impact of medium and cell density on survival of M. tuberculosis at pH 4.5. Cultures were plated after incubation for 6 days in 7H9 growth medium containing Tween 80 (squares), 7H9 growth medium containing tyloxapol (triangles), or phosphate citrate buffer containing tyloxapol (circles) at input densities ranging from 2.5 × 108 to 1 × 106 CFU/ml. Data are means ± standard deviations of triplicate cultures and represent two independent experiments. For the experimental protocol and a description of the media, please see reference .
See this image and copyright information in PMC

References

    1. Agranoff, D., I. M. Monahan, J. A. Mangan, P. D. Butcher, and S. Krishna. 1999. Mycobacterium tuberculosis expresses a novel pH-dependent divalent cation transporter belonging to the Nramp family. J. Exp. Med. 190717-724. - PMC - PubMed
    1. Akaki, T., H. Tomioka, T. Shimizu, S. Dekio, and K. Sato. 2000. Comparative roles of free fatty acids with reactive nitrogen intermediates and reactive oxygen intermediates in expression of the anti-microbial activity of macrophages against Mycobacterium tuberculosis. Clin. Exp. Immunol. 121302-310. - PMC - PubMed
    1. Alix, E., and A. B. Blanc-Potard. 2007. MgtC: a key player in intramacrophage survival. Trends Microbiol. 15252-256. - PubMed
    1. Alonso, S., K. Pethe, D. G. Russell, and G. E. Purdy. 2007. Lysosomal killing of Mycobacterium mediated by ubiquitin-derived peptides is enhanced by autophagy. Proc. Natl. Acad. Sci. USA 1046031-6036. - PMC - PubMed
    1. Armstrong, J. A., and P. D. Hart. 1975. Phagosome-lysosome interactions in cultured macrophages infected with virulent tubercle bacilli. Reversal of the usual nonfusion pattern and observations on bacterial survival. J. Exp. Med. 1421-16. - PMC - PubMed

Publication types

MeSH terms

LinkOut - more resources