Deletion of the rel gene in Mycobacterium smegmatis reduces its stationary phase survival without altering the cell-surface associated properties

Mathew, Renjith and Ojha, AK and Karande, AA and Chatterji, Dipankar (2004) Deletion of the rel gene in Mycobacterium smegmatis reduces its stationary phase survival without altering the cell-surface associated properties. In: Current Science, 86 (1). pp. 149-153.

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Abstract

Dormant or latent physiology of the mycobacterial species is a subject of current investigation in order to understand the long-term persistence of these organisms inside the host. It is argued that the carbon-starved mycobacteria may serve as a good model for the dormant bacilli. The relA/spoT gene is upregulated during carbon starvation in Mycobacterium tuberculosis and the deletion of the gene resulted in reduction of long-term persistence in M. tuberculosis. Overexpression of the gene in M. smegmatis changes the colony morphology of the bacteria. Here we show that knock-out of the relA/spoT gene compromises stationary-phase survival of M. smegmatis. However, the DeltarelA/spoT bacteria show similar profile of glycopeptidolipids as the wild-type bacteria under carbon starvation. We have seen here that M. smegmatis, a nonpathogenic species, upon carbon starvation exhibits reduced association with murine macrophage cell line RAW 264.7 in comparison to M. smegmatis grown in carbon-enriched medium. But the clearance of the a bacteria from macrophages takes place in the same window of time in both conditions.

Item Type:	Journal Article
Publication:	Current Science
Publisher:	Indian Academy of Sciences
Additional Information:	Copyright of this article belongs to Indian Academy of Sciences.
Keywords:	Tuberculosis;Glycopeptidolipids;Identification;Macrophages;Monocytes
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit Division of Biological Sciences > Biochemistry
Date Deposited:	18 Dec 2008 11:04
Last Modified:	19 Sep 2010 04:53
URI:	http://eprints.iisc.ac.in/id/eprint/16817

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