Neutral-red reaction is related to virulence and cell wall methyl-branched lipids in Mycobacterium tuberculosis

Cardona, Père-Joan; Soto, Carlos Y.; Martı́n, Carlos; Giquel, B.; Agustí, Gemma; Guirado, Evelyn; Sirakova, Tatiana D.; Kolattukudy, P.E.; Julián, Esther; Luquin, Marina

doi:10.1016/j.micinf.2005.06.011

Cited by 36 publications

(40 citation statements)

References 24 publications

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“…This W/Beijing isolate was first routinely cultured in laboratories around 1999 (Manca et al, 1999). Other researchers have noted that clinical isolate MT103 became defective in PDIM synthesis after being held in culture continuously for 18 months (Cardona et al, 2006). Finally, we have also screened a more recent W/Beijing clinical isolate ('B-4') that has spent only a minimal amount of time in in vitro culture.…”

Section: Discussionmentioning

confidence: 99%

Rapid and spontaneous loss of phthiocerol dimycocerosate (PDIM) from Mycobacterium tuberculosis grown in vitro: implications for virulence studies

2009

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Isolated in vitro more than half a century ago, the H37Rv strain of Mycobacterium tuberculosis still remains the strain of choice for the majority of laboratories conducting in vivo studies of TB pathogenesis. In this report we reveal that H37Rv is highly prone to losing the ability to synthesize the cell wall lipid phthiocerol dimycocerosate (PDIM) during extended periods of in vitro culture. In addition, H37Rv stocks that have been held in vitro for even a short length of time should be thought of as a heterogeneous population of PDIM-positive and PDIM-negative cell types. We demonstrate that after weekly subculture of PDIM-positive isolates over a period of 20 weeks, the proportion of PDIM-negative cells rises above 30 %. That PDIM biosynthesis is negatively selected in vitro is evident from the broad range of mutation types we observe within cultures originating from a single PDIM-positive parental clone. Moreover, the appearance of these multiple mutation types coupled with an enhanced growth rate of PDIM-negative bacteria ensures that 'PDIM-less' clones rapidly dominate in vitro cultures. It has been known for almost a decade that strains of M. tuberculosis that lack PDIM are severely attenuated during in vivo infection. Therefore, the loss of PDIM raises a very serious issue in regard to the interpretation of putative virulence factors where heterogeneous parental cultures are potentially being compared in vivo to recombinant clones isolated within a PDIM-negative background. It is essential that researchers undertaking in vivo virulence studies confirm the presence of PDIM within all recombinant clones and the parental strains they are derived from.

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Section: Discussionmentioning

confidence: 99%

Rapid and spontaneous loss of phthiocerol dimycocerosate (PDIM) from Mycobacterium tuberculosis grown in vitro: implications for virulence studies

2009

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“…The propionyl-CoA generated upon b-oxidation of cholesterol is converted to methylmalonyl-CoA by the propionyl-CoA carboxylase and then used by dedicated polyketide synthases in the elongation of the polymethyl-branched fatty acids esterifying PDIM, SL, DAT, and PAT. Independent from this metabolic function and suggestive of their collective role in the permeability of the cell envelope, Mtb mutants deficient in the synthesis of more than one polymethylbranched fatty acid -containing lipid (either PDIM and SL or DAT, PAT, and SL) but not mutants lacking only one lipid species, lose the ability to stain with neutral red (Cardona et al 2006). Finally, DAT and PAT have been involved in the retention of the capsular material at the surface of Mtb (Rousseau et al 2003a).…”

Section: Inner and Outer Membrane Extractable Lipidsmentioning

confidence: 99%

The Mycobacterial Cell Envelope--Lipids

Jackson

2014

Cold Spring Harbor Perspectives in Medicine

188

170

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“…1), is used for a variety of purposes such as biological staining [2], for medical purposes to investigate viruses [3], as a pH indicator in biochemical systems [4], in the determination of DNA using optical and electrochemical methods [5,6], for the evaluation of naturally-derived and synthetic biomaterials [7,8], for the development of optical sensors [9], etc. Like other phenazine derivatives, in particular azur A [10], azur B [11], toluidine blue O [12], methylene blue [13], methylene green [14], phenosafranin [15], NR can be polymerized electrochemically and form a conductive polymer [16 -21].…”

Section: Introductionmentioning

confidence: 99%

Poly(neutral red): Electrosynthesis, Characterization, and Application as a Redox Mediator

Pauliukaitė

Brett

2008

Electroanalysis

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The synthesis by electropolymerization, the characterization, and applications of poly(neutral red) (PNR), including as a redox mediator, are reviewed. PNRs high electrical conductivity and its redox characteristics have led to special applications of the polymer, and it has been used for the development of electrochemical and optical sensors. Moreover, the attractive properties of PNR allow it to be applied in the development of electrochemical biosensors. Future perspectives are indicated.

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Neutral-red reaction is related to virulence and cell wall methyl-branched lipids in Mycobacterium tuberculosis

Cited by 36 publications

References 24 publications

Rapid and spontaneous loss of phthiocerol dimycocerosate (PDIM) from Mycobacterium tuberculosis grown in vitro: implications for virulence studies

Rapid and spontaneous loss of phthiocerol dimycocerosate (PDIM) from Mycobacterium tuberculosis grown in vitro: implications for virulence studies

The Mycobacterial Cell Envelope--Lipids

Poly(neutral red): Electrosynthesis, Characterization, and Application as a Redox Mediator

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