High throughput sequencing-based analysis of microbial diversity in dental unit waterlines supports the importance of providing safe water for clinical use

Abstract

This study aims to explore the water quality of dental unit waterlines (DUWLs) and the diversity of microbial communities in DUWLs. Water samples from 33 dental chair units (DCUs) were collected, diluted and then spread on sterilized R2A plate for incubation. Subsequently, the microbial colony-forming units per milliliter (CFU/ml) were recorded by an automatic colony analyzer. Total DNA extracted from the rest of the samples was tested on the Illumina MiSeq PE300 platform. T-test and Kruskal-Wallis rank test were adopted for statistical analysis. Significance was assumed at a P<0.05. After incubation, the average total microbial count was 21,413.13±17,861.00CFU/ml. High-throughput sequencing revealed 10 bacterial phyla, including 9 identified and 1 unclassified phyla. Totally 63 sequences were identified at the genus level, including 42 genera, 3 tentative species and 18 unclassified genera. In addition, 7 potential human pathogenic bacteria were detected. In summary, department, brand and service life of DCUs do not influence the water quality of DUWLs significantly. The diversity of microbial communities in DUWLs is abundant and includes both pathogenic and some unknown bacteria.

Efficacy of BRS® and Alpron®/Bilpron® Disinfectants for Dental Unit Waterlines: A Six-Year Study

“…The DUWL output water often contains multiple bacteria in quantities greater than what is recommended [3,44]. Among those bacteria, opportunistic pathogenic bacteria like Pseudomonas and Legionella can be found [19,48] despite DUWL disinfectants [30,34]. Before this protocol, the microbiological quality of DUWL's water in our hospital was unsatisfactory and different punctual DUWL disinfectants were tested without prolonged success.…”

Bacteriological Safety of Water Filters for Dental Units: Evalutation of the Filtration Action against S. Aureus and E. Coli

“…To not mention the further risk of direct blood contagion during working with direct water flushing instruments on a patient undergoing surgical treatments that expose the oral mucosa to bleeding. This risk of contamination can significantly increase during long interventions, due to the continued exposure of the patient and operators to the dispersion of contaminated aerosols in the work place [9] . In order to find a suitable solution, capable of sanitizing the incoming water to the dental unit, it was decided to test a medical filtration device specifically designed for the dental unit and currently available on the market.…”

Assessment of microbiota present on a Portuguese historical stone convent using high‐throughput sequencing approaches

“…Small subunit ribosomal DNA genes like 16S and 18S universally present in all prokaryotes and eukaryotes, respectively, provide an efficient mean to identify microorganisms. These ribosomal sequences possess variable and highly conserved regions, which are used as phylogenetic markers to identify and distinguish the different microorganisms on all phylogenetic levels (Dakal & Arora, 2012; Kennedy & Clipson, 2003; Li, Zhang, He, & Yang, 2016; Zhang, Ping, Zhou, Wang, & Zhang, 2018). The internal transcribed spacer (ITS) region is also an effective tool for the identification of eukaryotic population (Anderson & Cairney, 2004; Dakal & Arora, 2012; Kennedy & Clipson, 2003).…”

“…Other nucleic acid approaches can be applied to detect uncultivable microorganisms. Recent developments in sequencing chemistries, bioinformatics, and automated instruments have revolutionized the knowledge of microbial diversity (Dyda et al, 2018; Edgar, Haas, Clemente, Quince, & Knight, 2011; England & Pettersson, 2005; Li et al, 2016; Mardis, 2008; Schubert, Lindgreen, & Orlando, 2016; Shendure & Ji, 2008; Zhang, Chiodini, Badr, & Zhang, 2011; Zhang et al, 2018; Zhou et al, 2015). The ongoing advances in genomics and sequencing technologies are allowing a new era of microbial community analyses using culture‐independent approaches such as metagenomics, metaproteomics, metatranscriptomics, and proteogenomics which are fundamental for the full identification of the microbial diversity and to understand their interactions with biotic and abiotic factors (Rastogi & Sani, 2011).…”

“…High‐throughput sequencing (HTS) technologies (also known as next generation sequencing—NGS) have revolutionized the study of microbial diversity. HTS is currently used in multidisciplinary fields in academic, clinical, and industrial settings, particularly to identify mammal species or to study microbial diversity in soils, freshwater, human guts, wastewater treatment facilities, and others (Jones et al, 2009; Nam, Jung, Roh, Kim, & Bae, 2011; Panek et al, 2018; Roh et al, 2009; Ronholm, 2018; Ye & Zhang, 2011; Zhang et al, 2018). This technology enables the characterization of microbial diversity but also allows a better knowledge about the functions, activities, and dynamics of microbial communities thriving in their natural environments (Zhou et al, 2015).…”