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Influence of long time storage in mineral water on RNA stability of Pseudomonas aeruginosa and Escherichia coli after heat inactivation.

Cenciarini C, Courtois S, Raoult D, La Scola B - PLoS ONE (2008)

Bottom Line: These nine transcripts were also analyzed in Escherichia coli after heat-killing and different to opposite results were obtained, notably for groEL which was the most labile transcript of E. coli.Moreover, opposite results were obtained between mineral water stored and freshly cultivated E. coli.This study highlights four potential viability markers for P. aeruginosa and four highly persistent transcripts.

View Article: PubMed Central - PubMed

Affiliation: Centre International de Recherche Sur l'Eau et l'Environnement - Suez Environnement, Le Pecq, France.

ABSTRACT

Background: Research of RNA viability markers was previously studied for many bacterial species. Few and different targets of each species have been checked and motley results can be found in literature. No research has been done about Pseudomonas aeruginosa in this way.

Methodology/principal findings: Disappearance of 48 transcripts was analyzed by two-steps reverse transcription and real time polymerase chain reaction (RT-PCR) after heat-killing of Pseudomonas aeruginosa previously stored in mineral water or not. Differential results were obtained for each target. 16S rRNA, 23S rRNA, groEL, and rpmE were showed as the most persistent transcripts and rplP, rplV, rplE and rpsD were showed as the most labile transcripts after P. aeruginosa death. However, the labile targets appeared more persistent in bacteria previously stored in mineral water than freshly cultivated (non stored). These nine transcripts were also analyzed in Escherichia coli after heat-killing and different to opposite results were obtained, notably for groEL which was the most labile transcript of E. coli. Moreover, opposite results were obtained between mineral water stored and freshly cultivated E. coli.

Conclusions and significance: This study highlights four potential viability markers for P. aeruginosa and four highly persistent transcripts. In a near future, these targets could be associated to develop an efficient viability kit. The present study also suggests that it would be difficult to determine universal RNA viability markers for environmental bacteria, since opposite results were obtained depending on the bacterial species and the physiological conditions.

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Study design.
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pone-0003443-g001: Study design.

Mentions: 48 transcripts corresponding to core genes plus spoT, sodB and groEL mRNAs, and ribosomal rRNAs were analyzed by real-time RT-PCR before (for positive control), immediately after and 24 hours after heat killing. Results were obtained from 3 aliquots proceeded in the same time (Figure 1, study design). According to total RNA profile observations, the real-time RT-PCR analysis showed that amounts of all of transcripts started to decrease immediately after heat treatment. Different levels of persistence, with fold-changes of 1.7×10−1 (or −0.78 log10) still 3.0×10−3 (or −2.52 log10), were observed immediately after bacterial heat-inactivation. As expected, ribosomal RNAs were among the most persistent transcripts (see supplementary data, figure S2.A).


Influence of long time storage in mineral water on RNA stability of Pseudomonas aeruginosa and Escherichia coli after heat inactivation.

Cenciarini C, Courtois S, Raoult D, La Scola B - PLoS ONE (2008)

Study design.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2566809&req=5

pone-0003443-g001: Study design.
Mentions: 48 transcripts corresponding to core genes plus spoT, sodB and groEL mRNAs, and ribosomal rRNAs were analyzed by real-time RT-PCR before (for positive control), immediately after and 24 hours after heat killing. Results were obtained from 3 aliquots proceeded in the same time (Figure 1, study design). According to total RNA profile observations, the real-time RT-PCR analysis showed that amounts of all of transcripts started to decrease immediately after heat treatment. Different levels of persistence, with fold-changes of 1.7×10−1 (or −0.78 log10) still 3.0×10−3 (or −2.52 log10), were observed immediately after bacterial heat-inactivation. As expected, ribosomal RNAs were among the most persistent transcripts (see supplementary data, figure S2.A).

Bottom Line: These nine transcripts were also analyzed in Escherichia coli after heat-killing and different to opposite results were obtained, notably for groEL which was the most labile transcript of E. coli.Moreover, opposite results were obtained between mineral water stored and freshly cultivated E. coli.This study highlights four potential viability markers for P. aeruginosa and four highly persistent transcripts.

View Article: PubMed Central - PubMed

Affiliation: Centre International de Recherche Sur l'Eau et l'Environnement - Suez Environnement, Le Pecq, France.

ABSTRACT

Background: Research of RNA viability markers was previously studied for many bacterial species. Few and different targets of each species have been checked and motley results can be found in literature. No research has been done about Pseudomonas aeruginosa in this way.

Methodology/principal findings: Disappearance of 48 transcripts was analyzed by two-steps reverse transcription and real time polymerase chain reaction (RT-PCR) after heat-killing of Pseudomonas aeruginosa previously stored in mineral water or not. Differential results were obtained for each target. 16S rRNA, 23S rRNA, groEL, and rpmE were showed as the most persistent transcripts and rplP, rplV, rplE and rpsD were showed as the most labile transcripts after P. aeruginosa death. However, the labile targets appeared more persistent in bacteria previously stored in mineral water than freshly cultivated (non stored). These nine transcripts were also analyzed in Escherichia coli after heat-killing and different to opposite results were obtained, notably for groEL which was the most labile transcript of E. coli. Moreover, opposite results were obtained between mineral water stored and freshly cultivated E. coli.

Conclusions and significance: This study highlights four potential viability markers for P. aeruginosa and four highly persistent transcripts. In a near future, these targets could be associated to develop an efficient viability kit. The present study also suggests that it would be difficult to determine universal RNA viability markers for environmental bacteria, since opposite results were obtained depending on the bacterial species and the physiological conditions.

Show MeSH
Related in: MedlinePlus