657. Evaluation of Nanopore-Based 16S Ribosomal RNA (rRNA) Gene Sequencing for the Development of a Rapid Infection Intervention Clinical Service

Abstract

BackgroundRapid and accurate identification of bacteria is the basis of appropriate antibiotic treatment and effective clinical decision-making. Next-generation sequencing (NGS) platforms such as Oxford Nanopore Technologies (ONT) holds the promise of a diagnostic revolution by overcoming the limitations of culture-based identification with rapid molecular detection of bacteria. We have developed a pilot to evaluate an ONT 16S rRNA gene assay with the ability to provide real-time analysis and identification of bacterial species. Our aim was to investigate whether long-read sequencing and high-speed analysis can be combined to create a clinically useful, rapid diagnostic tool.MethodsA collection of bacterial isolates representing pathogenic species received by the clinical laboratory over 1 year was assembled. Sample preparation was as described in the ONT 16S protocol and included bead beating sample disruption, MagNA Pure automated nucleic acid extraction (Roche), and PCR amplification (Thermo). Sequencing was performed on the MinION and GridION X5 platforms. Output was analyzed with ONT’s automated EPI2ME 16S pipeline which assigns reads to taxa using BLAST results and the NCBI 16S Bacterial database.ResultsA total of 155 clinical samples with 139 species were sequenced. 119 species were identified at the species level. For 20 samples, a species in the same genus claimed the majority of reads, with the true species being matched to 3%-41% of reads. The average proportion of reads assigned to the correct species was 62.2%, specifically 67% for non-Enterobacteriaceae and 33% for Enterobacteriaceae. 4 clinical samples (3 Bronchoalveolar lavages (BALs), positive for (1) K. pneumoniae, (2) S. pneumoniae, and (3) S. pneumoniae, S. enterica, and S. typhimurium, and 1 bone positive for P. aeruginosa) were also analyzed with sequencing results matching culture.ConclusionEarly results show that 16S rRNA sequencing coupled with real-time analysis was able to accelerate pathogen detection and was able to discriminate the majority of species from a relevant clinical collection. Pipeline refinement is required and subsequent confirmatory consensus-based identification may be a helpful adjunct. Nanopore sequencing shows promise as a rapid bacterial pathogen detection platform for clinical service.Disclosures All authors: No reported disclosures.