Quantitative reverse transcription polymerase chain reaction analysis of Vibrio cholerae cells entering the viable but non-culturable state and starvation in response to cold shock
Article first published online: 2 NOV 2005
Volume 8, Issue 4, pages 658–666, April 2006
How to Cite
González-Escalona, N., Fey, A., Höfle, M. G., Espejo, R. T. and A. Guzmán, C. (2006), Quantitative reverse transcription polymerase chain reaction analysis of Vibrio cholerae cells entering the viable but non-culturable state and starvation in response to cold shock. Environmental Microbiology, 8: 658–666. doi: 10.1111/j.1462-2920.2005.00943.x
- Issue published online: 8 MAR 2006
- Article first published online: 2 NOV 2005
- Received 27 July, 2005; accepted 28 September, 2005.
We performed a comparative analysis of the Vibrio cholerae strain El Tor 3083 entering the viable but non-culturable (VBNC) state and starvation after incubation in artificial seawater (ASW) at 4 and 15°C respectively. To this end, we determined bacterial culturability and membrane integrity, as well as the cellular levels of 16S rRNA and mRNA for the tuf, rpoS and relA genes, which were assessed by real-time quantitative reverse transcription polymerase chain reaction (Q-RT-PCR). Bacterial cells entering the VBNC state showed a 154, 5.1 × 103, 24- and 23-fold reduction in the number of copies of 16S rRNA and mRNA for tuf, rpoS and relA, in comparison to exponentially growing cells. The differences were less striking between cells in the VBNC and starvation states. The mRNA for relA was selectively increased in VBNC cells (3.2-folds), whereas a 3.9-fold reduction was observed for 16S rRNA. The obtained results confirmed that key activities of the cellular metabolism (i.e. tuf representing protein synthesis, and relA or rpoS stress response) were still detected in bacteria entering the VBNC state and starvation. These data suggest that the new Q-RT-PCR methodology, based on the selected RNA targets, could be successfully exploited for the identification (rRNA) of V. cholerae and assessment of its metabolic activity (tuf, rpoS, relA mRNA) in environmental samples.