Links between Nosocomial Endodontic Infections and Bacteremia Associated with Apical Periodontitis and Endodontic...

Nosocomial endodontic infections can cause treatment failure and are potential risk of bacteremia. This study is aimed to investigate bacteremia associated with apical periodontitis and immediate postendodontic treatment using next-generation sequencing. The study will also elucidate if the endodontic nosocomial pathogens are present in the blood microbiome.

Saliva, blood, and intracanal samples were collected from patients undergoing endodontic treatment (n = 65), while gloves samples were collected from the operator. Bacterial DNA was extracted and the targeted 16S ribosomal ribonucleic acid gene was sequenced using the Illumina Miseq 300 platform for the V1-V2 hypervariable region. The alpha and beta diversities were carried out using the phyloseq package (version-1.36.0) in R (version-4.1). Differences in abundance and diversity were calculated using Mann-Whitney test. Linear discriminant analysis Effect Size was used to compare the biological relevance between different sample sources.

The phyla firmicutes, actinobacteria, proteobacteria, and bacteroidetes were identified from all sample sources. In blood and glove samples, Cutibacterium genus was highly abundant (14.6%, 17.7%, respectively), while in intracanal samples, Enterococcus took precedence (18.2%). Saliva samples exhibited Prevotella as the most abundant genera (17.9%). Common genera were present between intracanal and postoperative blood samples. Circos graph showed that all the phyla identified from a patient were consistently present in all the samples investigated from the same patient.

Nosocomial endodontic pathogens being predominant in both; gloves and blood samples, along with common genera present in all sample sources, suggests a potential pathway of transfer of pathogens from saliva to gloves, intracanal, and blood, thus providing evidence of nosocomial endodontic bacteremia.