Evaluation of a quantitative RT-PCR assay for the detection of the emerging coronavirus SARS-CoV-2 using a high throughput system.

Facing the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), high-volume respiratory testing is demanded in laboratories worldwide. We evaluated the performance of a molecular assay for the detection of SARS-CoV-2 on a high-throughput platform, the cobas 6800, using the 'open channel' for integration of a laboratory-developed assay. We observed good analytical performance in clinical specimens. The fully automated workflow enables high-throughput testing with minimal hands-on time, while offering fast and reliable results.

Clinical evaluation of a laboratory-developed quantitative BK virus-PCR assay using the cobas® omni Utility Channel.

BACKGROUND: In immunocompromised patients, BK Virus (BKV) reactivation may cause serious disease with high morbidity. Particularly for patient management after solid organ transplantation, monitoring of viral load in different clinical specimens is crucial to ensure early diagnosis and response to reactivation. In this study, we evaluated the clinical performance of a custom designed primer /probe set for detection of BKV on the cobas® 6800, a high-throughput platform, employing the open channel of the system for integration of a lab-developed test (LDT). MATERIALS/METHODS: A primer/probe set was optimized for the use on a high-throughput platform. Clinical performance was assessed in EDTA-plasma, serum and urine samples. Limit-of-detection (LOD) was determined by using a dilution series of BKV WHO standard. A CE-labeled PCR test (Altona Diagnostics) was used as a comparison to the assay. RESULTS: The LOD for the LDT BKV assay was 6.7 IU/mL. Inter-and intra-run variability (at 5 x LOD) was low (<1.5 Ct in all specimens). All quality control panel specimens (Instand Germany n = 19) were correctly identified. Of 290 clinical samples tested, results were concordant for 280 samples. Sensitivity and specificity of the assay were 96 % and 98 % respectively. The quantitative analysis revealed a strong correlation (linear regression) between the CE-labelled comparator assay and the new BKV LDT assay with r2 = 0.96 for n = 123 urine samples and r2 = 0.98 for n = 167 plasma/serum samples. CONCLUSION: Compared to a CE-IVD assay, the adapted LDT showed good analytical and clinical sensitivity and specificity for the detection and quantification of BKV in different clinical specimens. It represents a convenient solution to automate the LDT workflow with low hands-on time and thus facilitates high-throughput screening for BKV reactivation in immunocompromised patients.

SARS Coronavirus-2 variant tracing within the first Coronavirus Disease 19 clusters in northern Germany.

OBJECTIVES: Investigation whether in depth characterization of virus variant patterns can be used for epidemiological analysis of the first severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection clusters in Hamburg, Germany. METHODS: Metagenomic RNA-sequencing and amplicon-sequencing and subsequent variant calling in 25 respiratory samples from SARS-CoV-2 infected patients involved in the earliest infection clusters in Hamburg. RESULTS: Amplikon sequencing and cluster analyses of these SARS-CoV-2 sequences allowed the identification of the first infection cluster and five non-related infection clusters occurring at the beginning of the viral entry of SARS-CoV-2 in the Hamburg metropolitan region. Viral genomics together with epidemiological analyses revealed that the index patient acquired the infection in northern Italy and transmitted it to two out of 134 contacts. Single nucleotide polymorphisms clearly distinguished the virus variants of the index and other clusters and allowed us to track in which sequences worldwide these mutations were first described. Minor variant analyses identified the transmission of intra-host variants in the index cluster and household clusters. CONCLUSIONS: SARS-CoV-2 variant tracing allows the identification of infection clusters and the follow up of infection chains occurring in the population. Furthermore, the follow up of minor viral variants in infection clusters can provide further resolution on transmission events indistinguishable at a consensus sequence level.