| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Physiology and Growth |
Department of Biology, Imperial College of Science, Technology and Medicine, Imperial College Road, London SW7 2AZ, UK1
Author for correspondence: Huw D. Williams. Tel: +44 20 75945383. Fax: +44 20 75842056. e-mail: h.d.williams{at}ic.ac.uk
A bank of 600 insertional mutants of Mycobacterium smegmatis was screened for mutants defective in stationary-phase survival. Of 74 mutants picked by the initial screen, 21 had stationary-phase survival defects and 7 of these were studied in more detail. In general, mutants survived stationary phase significantly less well in rich medium than under carbon-starvation conditions. In all cases the loss of viability in stationary phase was not complete even after prolonged incubation. All mutants showed an initial decrease in viability, during the first 40 d in stationary phase, followed by an increase in viable counts that returned viability close to the levels of the wild-type. Southern hybridization experiments showed that recovery of viability was not a consequence of precise excision or movement of the transposon. Two of the survival mutants differed from the wild-type in their colony morphology, and recovery of their viability in stationary phase was coincident with the return of wild-type colony morphology. It is possible that second-site suppressor mutations accumulate that alleviate the effects of the original mutation. For five of the mutants the DNA flanking the site of transposition was amplified by ligation-mediated PCR and sequenced to identify the disrupted locus. In each case, homologous genes were identified in the Mycobacterium tuberculosis genome, three of which have clearly predicted functions in M. tuberculosis as a penicillin-binding protein, in biotin biosynthesis and as a polyketide synthase. This is the first identification of genes implicated in the stationary-phase survival of mycobacteria.
Keywords: starvation, dormancy, colony morphology, latency, tuberculosis
The GenBank accession numbers for the sequences determined in this work are: AJ277088 (mutant 272A), AJ277089 (mutant 272E), AJ27790 (mutant 317C), AJ277152 (mutant 492A) and AJ276883 (mutant 3910D).
a Present address: LGC, Queens Road, Middlesex TW11 0LY, UK.
This article has been cited by other articles:
|
|
 |
|
  M. C. J. Blokpoel, M. J. Smeulders, J. A. M. Hubbard, J. Keer, and H. D. Williams Global Analysis of Proteins Synthesized by Mycobacterium smegmatis Provides Direct Evidence for Physiological Heterogeneity in Stationary-Phase Cultures J. Bacteriol., October 1, 2005; 187(19): 6691 - 6700. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. R. Flores, L. M. Parsons, and M. S. Pavelka Jr. Characterization of Novel Mycobacterium tuberculosis and Mycobacterium smegmatis Mutants Hypersusceptible to {beta}-Lactam Antibiotics J. Bacteriol., March 15, 2005; 187(6): 1892 - 1900. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. M. King Uptake of Carbon Monoxide and Hydrogen at Environmentally Relevant Concentrations by Mycobacteria{dagger} Appl. Envir. Microbiol., December 1, 2003; 69(12): 7266 - 7272. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. O'Toole, M. J. Smeulders, M. C. Blokpoel, E. J. Kay, K. Lougheed, and H. D. Williams A Two-Component Regulator of Universal Stress Protein Expression and Adaptation to Oxygen Starvation in Mycobacterium smegmatis J. Bacteriol., March 1, 2003; 185(5): 1543 - 1554. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Goffin and J.-M. Ghuysen Biochemistry and Comparative Genomics of SxxK Superfamily Acyltransferases Offer a Clue to the Mycobacterial Paradox: Presence of Penicillin-Susceptible Target Proteins versus Lack of Efficiency of Penicillin as Therapeutic Agent Microbiol. Mol. Biol. Rev., December 1, 2002; 66(4): 702 - 738. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M. Talaat, S. T. Howard, W. Hale IV, R. Lyons, H. Garner, and S. A. Johnston Genomic DNA standards for gene expression profiling in Mycobacterium tuberculosis Nucleic Acids Res., October 15, 2002; 30(20): e104 - e104. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. O. Shleeva, K. Bagramyan, M. V. Telkov, G. V. Mukamolova, M. Young, D. B. Kell, and A. S. Kaprelyants Formation and resuscitation of 'non-culturable' cells of Rhodococcus rhodochrous and Mycobacterium tuberculosis in prolonged stationary phase Microbiology, May 1, 2002; 148(5): 1581 - 1591. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Keer, M. J. Smeulders, and H. D. Williams A purF mutant of Mycobacterium smegmatis has impaired survival during oxygen-starved stationary phase Microbiology, February 1, 2001; 147(2): 473 - 481. [Abstract] [Full Text]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |
