This study highlights four potential viability markers for P. aeruginosa and four highly persistent transcripts.
RplV mRNA appeared as the most persistent transcripts, whereas groEL, rpmE and obg became the most labile.
We also confirmed that 16S and 23S ribosomal RNAs were among the most persistent transcripts [1], [10], [26] [28].
Ratios calculated between fold change of the most labile and the most persistent transcripts are showed in Table 2.
From persistent transcripts, the average fold decrease was of −1.13 log10 and groEL mRNA appeared more persistent than 23S rRNA by using SYBR green.
In the persistent transcripts group, 16S rRNA was also one of the most persistent transcripts in freshly cultivated E. coli population, but rpmE mRNA showed an intermediate level of decrease and groEL mRNA was the less persistent from freshly cultivated E. coli in contrast to P. aeruginosa.
Finally, after testing these 48 transcripts, 12 could be considered as labile transcripts with a minimum fold decrease of −2.65 log10 (value arbitrary chosen), and 11 of them could be considered as persistent transcripts with a maximum fold decrease of −1.75 log10.
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.
rplP, rplV, rplE and rpsD mRNAs were selected among the labile transcript, and obg, groEL and rpmE mRNAs and 16S and 23S rRNAs were selected among the persistent transcripts.
As showed in Table 2, the best ratio obtained between fold changes of labile and persistent transcripts on mineral water stored bacteria was obtained with 23S rRNA/rplP with a value of 20.
