Abstract
Enterococcus faecalis is the most commonly isolated species from endodontic failure root canals; its persistence in treated root canals has been attributed to its ability to resist high pH stress. The goal of this study was to characterize the E. faecalis transcriptome and to identify candidate genes for response and resistance to alkaline stress using Illumina HiSeq 2000 sequencing. We found that E. faecalis could survive and form biofilms in a pH 10 environment and that alkaline stress had a great impact on the transcription of many genes in the E. faecalis genome. The transcriptome sequencing results revealed that 613 genes were differentially expressed (DEGs) for E. faecalis grown in pH 10 medium; 211 genes were found to be differentially up-regulated and 402 genes differentially down-regulated. Many of the down-regulated genes found are involved in cell energy production and metabolism and carbohydrate and amino acid metabolism, and the up-regulated genes are mostly related to nucleotide transport and metabolism. The results presented here reveal that cultivation of E. faecalis in alkaline stress has a profound impact on its transcriptome. The observed regulation of genes and pathways revealed that E. faecalis reduced its carbohydrate and amino acid metabolism and increased nucleotide synthesis to adapt and grow in alkaline stress. A number of the regulated genes may be useful candidates for the development of new therapeutic approaches for the treatment of E. faecalis infections.
Highlights
Enterococcus spp. are natural inhabitants of the gastrointestinal tracts of humans and animals (Creti et al, 2004), but they can be found in water, soil, and vegetables (Burgos et al, 2009)
Genomic Analysis Because there is no sequence data publicly available for E. faecalis ATCC33186, genome sequencing was performed before transcriptional analysis to obtain a detailed account of the genetic expression and to validate the performance of our RNA-Seq
De novo transcriptome sequencing of E. faecalis using the Illumina 2000 was performed for the first time
Summary
Enterococcus spp. are natural inhabitants of the gastrointestinal tracts of humans and animals (Creti et al, 2004), but they can be found in water, soil, and vegetables (Burgos et al, 2009). The two most important species, Enterococcus faecium and Enterococcus faecalis, are most frequently implicated in human and animal infections (Aakra et al, 2005). They have been reported to be associated with oral mucosal lesions in immunocompromised patients, periodontitis, and root canal infections (Wahlin and Holm, 1988; Rams et al, 1992; Siqueira and Rôças, 2004). It has been reported that in teeth with necrotic pulps, E. faecalis has rarely been isolated by culturing (4%), but has frequently been detected by PCR (82%); it is detected as occurring frequently in teeth with failing endodontic treatment. E. faecalis may occur in low numbers in necrotic pulp, keeping it from being cultured from these
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
