Transcriptional activity around bacterial cell death reveals molecular biomarkers for cell viability
article
Background: In bacteriology, the ability to grow in selective media and to form colonies on nutrient agar plates is routinely used as a retrospective criterion for the detection of living bacteria. However, the utilization of indicators for bacterial viability-such as the presence of specific transcripts or membrane integrity-would overcome bias introduced by cultivation and reduces the time span of analysis from initiation to read out. Therefore, we investigated the correlation between transcriptional activity, membrane integrity and cultivation-based viability in the Gram-positive model bacterium Bacillus subtilis. Results: We present microbiological, cytological and molecular analyses of the physiological response to lethal heat stress under accurately defined conditions through systematic sampling of bacteria from a single culture exposed to gradually increasing temperatures. We identified a coherent transcriptional program including known heat shock responses as well as the rapid expression of a small number of sporulation and competence genes, the latter only known to be active in the stationary growth phase. Conclusion: The observed coordinated gene expression continued even after cell death, in other words after all bacteria permanently lost their ability to reproduce. Transcription of a very limited number of genes correlated with cell viability under the applied killing regime. The transcripts of the expressed genes in living bacteria - but silent in dead bacteria-include those of essential genes encoding chaperones of the protein folding machinery and can serve as molecular biomarkers for bacterial cell viability. © 2008 Kort et al; licensee BioMed Central Ltd.
Chemicals / CAS: Biological Markers; RNA, Bacterial
Chemicals / CAS: Biological Markers; RNA, Bacterial
Topics
BiotechnologyBacterial RNARibosome RNABiological markerArticleBacillus subtilisBacterial cellBacterial growthBacterial membraneBacterial reproductionCell cultureCell deathCell viabilityCellular stress responseControlled studyCytologyGene clusterGene expressionGenetic transcriptionGrowth curveHeat stressNonhumanProtein foldingRNA stabilitySporogenesisTranscription regulationBacterial countDNA microarrayGene expression profilingGene expression regulationGeneticsGrowth, development and agingHeatHeat shock responseMicrobial viabilityMultigene familyPhysiologyTranscription initiationBacillus subtilisBacteria (microorganisms)PosibacteriaBacillus subtilisBiological MarkersColony Count, MicrobialGene Expression ProfilingGene Expression Regulation, BacterialHeat-Shock ResponseHot TemperatureMicrobial ViabilityMultigene FamilyOligonucleotide Array Sequence AnalysisRNA StabilityRNA, BacterialTranscription, GeneticTranscriptional Activation
TNO Identifier
241277
ISSN
14712164
Source
BMC Genomics, 9
Article nr.
No.: 590