High-resolution and real-time wastewater viral surveillance by Nanopore sequencing.

Wastewater genomic sequencing stands as a pivotal complementary tool for viral surveillance in populations. While long-read Nanopore sequencing is a promising platform to provide real-time genomic data, concerns over the sequencing accuracy of the earlier Nanopore versions have somewhat restrained its widespread application in wastewater analysis. Here, we evaluate the latest improved version of Nanopore sequencing (R10.4.1), using SARS-CoV-2 as the model infectious virus, to demonstrate its effectiveness in wastewater viral monitoring. By comparing amplicon lengths of 400 bp and 1200 bp, we revealed that shorter PCR amplification is more suitable for wastewater samples due to viral genome fragmentation. Utilizing mock wastewater samples, we validated the reliability of Nanopore sequencing for variant identification by comparing it with Illumina sequencing results. The strength of Nanopore sequencing in generating real-time genomic data for providing early warning signals was also showcased, indicating that as little as 0.001 Gb of data can provide accurate results for variant prevalence. Our evaluation also identified optimal alteration frequency cutoffs (>50 %) for precise mutation profiling, achieving >99 % precision in detecting single nucleotide variants (SNVs) and insertions/deletions (indels). Monitoring two major wastewater treatment plants in Hong Kong from September 2022 to April 2023, covering over 4.5 million population, we observed a transition in dominant variants from BA.5 to XBB lineages, with XBB.1.5 being the most prevalent variants. Mutation detection also highlighted the potential of wastewater Nanopore sequencing in uncovering novel mutations and revealed links between signature mutations and specific variants. This study not only reveals the environmental implications of Nanopore sequencing in SARS-CoV-2 surveillance but also underscores its potential in broader applications including environmental health monitoring of other epidemic viruses, which could significantly enhance the field of wastewater-based epidemiology.

Efficacy of root canal therapy combined with basic periodontal therapy and its impact on inflammatory responses in patients with combined periodontal-endodontic lesions.

OBJECTIVE: To investigate the effect of root canal and basic periodontal therapies on the efficacy and inflammatory response in patients with pulpal-periodontal disease. METHODS: Clinical data of 103 patients with combined periodontal-endodontic lesions were retrospectively analyzed. The patients were divided into a control group (n=50, treated with conventional root canal therapy) and an observation group (n=53, treated with root canal and basic periodontal therapies). The clinical efficacy after treatment, as well as the probing pocket depth (PD), periodontal indices, inflammatory factors release, and pain level (visual analogue scale) before and after treatment were compared between the two groups. The status of diseased teeth and adverse reactions after treatment were recorded. RESULTS: After 1 month of treatment, the observation group had lower incidences of loosening of teeth, periodontitis and total adverse reactions, as well as higher tooth retention rate and effective rate as compared with the control group (all P<0.05). The PD, BI, PLI, GI and serum levels of interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) all decreased in both groups after 1 month of treatment, and the decreases were more in the observation group than those in the control group (all P<0.05). Compared with before treatment, scores of visual analogue scale decreased in both groups 48 hours after the drug was sealed and 1 month after treatment, and the decreases were more in the observation group than those in the control group (all P<0.05). CONCLUSION: Root canal and basic periodontal therapies can significantly reduce the pain, control the progression of oral inflammation, improve periodontal health and increase the retention rate of affected teeth in patients with combined periodontal-endodontic lesions, showing safety and efficacy.