Current metagenomic approaches to the study of complex microbial consortia provide a glimpse into the community metabolism and occasionally allow genomic assemblies for the most abundant organisms. However, little information is gained for the members of the community present at low frequencies, especially those representing yet-uncultured taxa, which include the bulk of the diversity present in most environments. Here we used phylogenetically directed cell separation by fluorescence in situ hybridization and flow cytometry, followed by amplification and sequencing of a fraction of the genomic DNA of several bacterial cells that belong to the TM7 phylum. Partial genomic assembly allowed, for the first time, a look into the evolution and potential metabolism of a soil representative from this group of organisms for which there are no species in stable laboratory cultures. Genomic reconstruction from targeted cells of uncultured organisms isolated directly from the environment represents a powerful approach to access any specific members of a community and an alternative way to assess the community's metabolic potential.Over the last several years, there has been an unprecedented surge in the number and diversity of genomic approaches used to study microbial communities (24, 45). While sequencebased methods and functional screening have been used successfully over the past decade to discover specific genes and gene products from the environment (42), most of the research was focused on a few metabolic markers or was aimed primarily at biotechnological applications (29). A number of approaches have been developed to better understand the structure of microbial communities and to establish links between specific organisms and the metabolic potential encoded in their genes. Among these, fluorescence in situ hybridization (FISH)
The COVID-19 pandemic caused by the new SARS-CoV-2 coronavirus has imposed severe challenges on laboratories in their effort to achieve sufficient diagnostic testing capability for identifying infected individuals. In this study we report the analytical and clinical performance characteristics of a new, high-throughput, fully automated nucleic acid amplification test system for the detection of SARS-CoV-2. The assay utilizes target capture, transcription mediated amplification, and acridinium ester-labeled probe chemistry on the automated Panther System to directly amplify and detect two separate target sequences in the ORF1ab region of the SARS-CoV-2 RNA genome. The probit 95% limit of detection of the assay was determined to be 0.004 TCID50/ml using inactivated virus, and 25 c/ml using synthetic in vitro transcript RNA targets. Analytical sensitivity (100% detection) was confirmed to be 83 – 194 c/ml using three commercially available SARS-CoV-2 nucleic acid controls. No cross reactivity or interference was observed with testing six related human coronaviruses, as well as 24 other viral, fungal, and bacterial pathogens, at high titer. Clinical nasopharyngeal swab specimen testing (N=140) showed 100%, 98.7%, and 99.3% positive, negative, and overall agreement, respectively, with a validated reverse transcription PCR NAAT for SARS-CoV-2 RNA. These results provide validation evidence for a sensitive and specific method for pandemic-scale automated molecular diagnostic testing for SARS-CoV-2.
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