An Assessment of the Bacterial Diversity found in Dental Unit Waterlines using the Illumina MiSeq.

Water from the waterlines of dental units is often contaminated with bacteria but there have been few studies accurately assessing the diversity of these bacterial populations. The aim of our study was to assess the bacterial diversity present in water collected from dental unit waterlines using the Illumina MiSeq. Water was collected from two separate dental units located in a dental hospital and two units found in two separate private clinics in Gangneung-si, Korea. From the four water samples that were analyzed, a total of 233 bacterial genera were identified. The most abundant genera were Sphingomonas (25%), Halomonas (20%), Reyranella (8%), and Novosphingobium (6%). Halomonas was more prevalent in the two dental units located at the dental hospital, while Reyranella and Sphingomonas were more commonly found in the private dental clinics. Only 19 of the 233 identified genera were common between water samples from all dental units. Opportunistic pathogens were shown to account for 7.7% of the total bacterial genera identified. Our results have demonstrated that there is a wide assortment of bacterial genera present in dental unit waterlines.