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Potassium availability triggers Mycobacterium tuberculosis transition to, and resuscitation from, non-culturable (dormant) states.

Salina EG, Waddell SJ, Hoffmann N, Rosenkrands I, Butcher PD, Kaprelyants AS - Open Biol (2014)

Bottom Line: In particular, latent tuberculosis may result from the maintenance of Mycobacterium tuberculosis bacilli in non-replicating states in infected individuals.Uniquely, growth of M. tuberculosis in aerobic conditions in potassium-deficient media resulted in the generation of bacilli that were non-culturable (NC) on solid media but detectable in liquid media.Transcriptomic and proteomic profiling through adaptation to, and resuscitation from, this NC state revealed a switch to anaerobic respiration and a shift to lipid and amino acid metabolism.

View Article: PubMed Central - PubMed

Affiliation: Institution of the Russian Academy of Sciences A.N. Bach Institute of Biochemistry RAS, Moscow, Russia elenasalina@yandex.ru.

ABSTRACT
Dormancy in non-sporulating bacteria is an interesting and underexplored phenomenon with significant medical implications. In particular, latent tuberculosis may result from the maintenance of Mycobacterium tuberculosis bacilli in non-replicating states in infected individuals. Uniquely, growth of M. tuberculosis in aerobic conditions in potassium-deficient media resulted in the generation of bacilli that were non-culturable (NC) on solid media but detectable in liquid media. These bacilli were morphologically distinct and tolerant to cell-wall-targeting antimicrobials. Bacterial counts on solid media quickly recovered after washing and incubating bacilli in fresh resuscitation media containing potassium. This resuscitation of growth occurred too quickly to be attributed to M. tuberculosis replication. Transcriptomic and proteomic profiling through adaptation to, and resuscitation from, this NC state revealed a switch to anaerobic respiration and a shift to lipid and amino acid metabolism. High concordance with mRNA signatures derived from M. tuberculosis infection models suggests that analogous NC mycobacterial phenotypes may exist during disease and may represent unrecognized populations in vivo. Resuscitation of NC bacilli in potassium-sufficient media was characterized by time-dependent activation of metabolic pathways in a programmed series of processes that probably transit bacilli through challenging microenvironments during infection.

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The transcriptional response of M. tuberculosis bacilli to resuscitation from an NC state. A total of 2146 genes significantly differentially expressed in NC bacilli compared with log-phase growth (log +K) or after resuscitation (Res) are shown. Biological replicates of conditions are displayed as columns, genes as rows. Red colouring represents induction of gene expression relative to NC, blue represents repression. Log2 expression ratios are plotted and the colour scale depicts fold change relative to NC. The columns on the right indicate in which comparison genes were identified to be significantly differentially expressed: (a) Res 24 versus NC; (b) Res 96 versus NC; (c) Res 192 versus NC; (d) NC versus +K+ log phase. The colouring of these markers indicates direction of expression (red, induction; blue repression).
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RSOB140106F4: The transcriptional response of M. tuberculosis bacilli to resuscitation from an NC state. A total of 2146 genes significantly differentially expressed in NC bacilli compared with log-phase growth (log +K) or after resuscitation (Res) are shown. Biological replicates of conditions are displayed as columns, genes as rows. Red colouring represents induction of gene expression relative to NC, blue represents repression. Log2 expression ratios are plotted and the colour scale depicts fold change relative to NC. The columns on the right indicate in which comparison genes were identified to be significantly differentially expressed: (a) Res 24 versus NC; (b) Res 96 versus NC; (c) Res 192 versus NC; (d) NC versus +K+ log phase. The colouring of these markers indicates direction of expression (red, induction; blue repression).

Mentions: Significantly differentially expressed genes were identified by comparing each time interval after resuscitation to NC state (figures 4 and 5). Two genes were significantly induced at Res 24 h time point, 68 upregulated at Res 96 h time point (108 repressed) and 769 genes induced at Res 192 h time point (881 repressed) (electronic supplementary material, table S4). Early responsive genes (within the first 96 h of resuscitation, before metabolic activity, MPN and optical density increased) included genes involved in the TCA cycle (gltA2, icd2, sdhB), FASII cycle (hadA, inhA), ATP synthesis (atpE) and NADH dehydrogenase I (nuoD, nuoH, nuoM), together with a small number of ribosomal genes (rplI, rplL, rplM, rplP, rpsQ). Of those genes repressed early on resuscitation were genes encoding NADH dehydrogenase II (ndh), ketoacid catabolism (bkdA), metal transporters (ctpC, ctpH, ctpJ) and the alternative sigma factors (sigF, sigL).Figure 4.


Potassium availability triggers Mycobacterium tuberculosis transition to, and resuscitation from, non-culturable (dormant) states.

Salina EG, Waddell SJ, Hoffmann N, Rosenkrands I, Butcher PD, Kaprelyants AS - Open Biol (2014)

The transcriptional response of M. tuberculosis bacilli to resuscitation from an NC state. A total of 2146 genes significantly differentially expressed in NC bacilli compared with log-phase growth (log +K) or after resuscitation (Res) are shown. Biological replicates of conditions are displayed as columns, genes as rows. Red colouring represents induction of gene expression relative to NC, blue represents repression. Log2 expression ratios are plotted and the colour scale depicts fold change relative to NC. The columns on the right indicate in which comparison genes were identified to be significantly differentially expressed: (a) Res 24 versus NC; (b) Res 96 versus NC; (c) Res 192 versus NC; (d) NC versus +K+ log phase. The colouring of these markers indicates direction of expression (red, induction; blue repression).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4221891&req=5

RSOB140106F4: The transcriptional response of M. tuberculosis bacilli to resuscitation from an NC state. A total of 2146 genes significantly differentially expressed in NC bacilli compared with log-phase growth (log +K) or after resuscitation (Res) are shown. Biological replicates of conditions are displayed as columns, genes as rows. Red colouring represents induction of gene expression relative to NC, blue represents repression. Log2 expression ratios are plotted and the colour scale depicts fold change relative to NC. The columns on the right indicate in which comparison genes were identified to be significantly differentially expressed: (a) Res 24 versus NC; (b) Res 96 versus NC; (c) Res 192 versus NC; (d) NC versus +K+ log phase. The colouring of these markers indicates direction of expression (red, induction; blue repression).
Mentions: Significantly differentially expressed genes were identified by comparing each time interval after resuscitation to NC state (figures 4 and 5). Two genes were significantly induced at Res 24 h time point, 68 upregulated at Res 96 h time point (108 repressed) and 769 genes induced at Res 192 h time point (881 repressed) (electronic supplementary material, table S4). Early responsive genes (within the first 96 h of resuscitation, before metabolic activity, MPN and optical density increased) included genes involved in the TCA cycle (gltA2, icd2, sdhB), FASII cycle (hadA, inhA), ATP synthesis (atpE) and NADH dehydrogenase I (nuoD, nuoH, nuoM), together with a small number of ribosomal genes (rplI, rplL, rplM, rplP, rpsQ). Of those genes repressed early on resuscitation were genes encoding NADH dehydrogenase II (ndh), ketoacid catabolism (bkdA), metal transporters (ctpC, ctpH, ctpJ) and the alternative sigma factors (sigF, sigL).Figure 4.

Bottom Line: In particular, latent tuberculosis may result from the maintenance of Mycobacterium tuberculosis bacilli in non-replicating states in infected individuals.Uniquely, growth of M. tuberculosis in aerobic conditions in potassium-deficient media resulted in the generation of bacilli that were non-culturable (NC) on solid media but detectable in liquid media.Transcriptomic and proteomic profiling through adaptation to, and resuscitation from, this NC state revealed a switch to anaerobic respiration and a shift to lipid and amino acid metabolism.

View Article: PubMed Central - PubMed

Affiliation: Institution of the Russian Academy of Sciences A.N. Bach Institute of Biochemistry RAS, Moscow, Russia elenasalina@yandex.ru.

ABSTRACT
Dormancy in non-sporulating bacteria is an interesting and underexplored phenomenon with significant medical implications. In particular, latent tuberculosis may result from the maintenance of Mycobacterium tuberculosis bacilli in non-replicating states in infected individuals. Uniquely, growth of M. tuberculosis in aerobic conditions in potassium-deficient media resulted in the generation of bacilli that were non-culturable (NC) on solid media but detectable in liquid media. These bacilli were morphologically distinct and tolerant to cell-wall-targeting antimicrobials. Bacterial counts on solid media quickly recovered after washing and incubating bacilli in fresh resuscitation media containing potassium. This resuscitation of growth occurred too quickly to be attributed to M. tuberculosis replication. Transcriptomic and proteomic profiling through adaptation to, and resuscitation from, this NC state revealed a switch to anaerobic respiration and a shift to lipid and amino acid metabolism. High concordance with mRNA signatures derived from M. tuberculosis infection models suggests that analogous NC mycobacterial phenotypes may exist during disease and may represent unrecognized populations in vivo. Resuscitation of NC bacilli in potassium-sufficient media was characterized by time-dependent activation of metabolic pathways in a programmed series of processes that probably transit bacilli through challenging microenvironments during infection.

Show MeSH
Related in: MedlinePlus