AUTHOR=Gaeta Carlo , Marruganti Crystal , Ali Islam A. A. , Fabbro Andrea , Pinzauti David , Santoro Francesco , Neelakantan Prasanna , Pozzi Gianni , Grandini Simone 

TITLE=The presence of Enterococcus faecalis in saliva as a risk factor for endodontic infection

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2023.1061645

DOI=10.3389/fcimb.2023.1061645

ISSN=2235-2988

ABSTRACT=<sec><title>Aim</title><p>The aim of the present study was to investigate and correlate the prevalence of <italic>Enterococcus faecalis</italic> in saliva and in root canals with different pulpal and periapical conditions.</p></sec><sec><title>Methodology</title><p>Sixty-seven patients were divided into five groups based on pulpal and periapical tissue status: healthy vital teeth (HVT, n=7), healthy treated teeth without lesion (HTT, n=9), irreversible pulpitis (IP, n=13), necrosis (N, n=18), and post-treatment apical periodontitis (PTAP, n=20). Saliva, rubber dam, sterility control and pre-treatment root canal samples were collected and microbiologically processed by culture method. The phylogenetic relationship of <italic>E. faecalis</italic> isolates collected from root canals and saliva were investigated by whole genome sequencing. Fisher’s exact test was used to correlate the presence of <italic>E. faecalis</italic> in root canals or saliva with clinical and/or radiographic findings. Linear/logistic regression analyses were performed to establish the relationship between the presence of <italic>E. faecalis</italic> in root canals, saliva, and the status of periapical tissues.</p></sec><sec><title>Results</title><p><italic>E. faecalis</italic> was found in 18 root canal and saliva samples. <italic>E. faecalis</italic> root canal isolates were recovered with the highest frequency from post-treatment apical periodontitis. The occurrence of <italic>E. faecalis</italic> in saliva was strongly associated with its detection in the root canals (<italic>P</italic> &lt; 0.001). The pretreatment presence of <italic>E. faecalis</italic> in root canals was associated with significantly higher odds of having periapical lesions (OR=11.03; 95% CI, 1.27-95.70; <italic>p</italic> &lt; 0.05). Saliva and root canal isolates from the same patient were highly correlated at the phylogenetic level (Jaccard index &gt;0.95).</p></sec><sec><title>Conclusion</title><p>This pilot study confirms the role of <italic>E. faecalis</italic> in developing peri-radicular lesions in secondary endodontic infections and suggests that saliva could be the main source of infection. Further studies are needed to investigate the exact origin of this bacteria and its true role in the pathogenesis of secondary/persistent endodontic infections.</p></sec>