Development of a targeted amplicon sequencing method for genotyping from fresh produce and clinical samples with enhanced genomic resolution and sensitivity.

Outbreaks of cyclosporiasis, an enteric illness caused by the parasite , have been associated with consumption of various types of fresh produce. Although a method is in use for genotyping from clinical specimens, the very low abundance of in food and environmental samples presents a greater challenge. To complement epidemiological investigations, a molecular surveillance tool is needed for use in genetic linkage of food vehicles to cyclosporiasis illnesses, estimation of the scope of outbreaks or clusters of illness, and determination of geographical areas involved.

A comprehensive HPV-STI NGS assay for detection of 29 HPV types and 14 non-HPV sexually transmitted infections.

Background: Sexually transmitted infections (STIs) are prevalent throughout the world and impose a significant burden on individual health and public health systems. Missed diagnosis and late treatment of STIs can lead to serious complications such as infertility and cervical cancer. Although sexually transmitted co-infections are common, most commercial assays target one or a few STIs.

Navigating the Pandemic Response Life Cycle: Molecular Diagnostics and Immunoassays in the Context of COVID-19 Management.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To counter COVID-19 spreading, an infrastructure to provide rapid and thorough molecular diagnostics and serology testing is the cornerstone of outbreak and pandemic management. We hereby review the clinical insights with regard to using molecular tests and immunoassays in the context of COVID-19 management life cycle: the preventive phase, the preparedness phase, the response phase and the recovery phase.

Differential expression of viral agents in lymphoma tissues of patients with ABC diffuse large B-cell lymphoma from high and low endemic infectious disease regions.

Diffuse large B-cell lymphoma (DLBCL), the most common type of non-Hodgkin's lymphoma (NHL) in adults, accounts for approximately 30-40% of newly diagnosed lymphomas worldwide. Environmental factors, such as viruses and bacteria, may contribute to cancer development through chronic inflammation and the integration of oncogenes, and have previously been indicated in cervical cancer, hepatocellular carcinoma, gastric cancer and lymphoproliferative disorders. In the present study, the presence of microbial agents was analyzed in the lymphoma tissue of patients with activated B-cell like (ABC) DLBCL.

Prevalence and genotype distribution of cervical human papillomavirus (HPV) among women in urban Tianjin, China.

To investigate the prevalence and genotype distribution of human papillomavirus (HPV) infection among women in urban Tianjin, China. A cervical cancer screening program for 2,000 women aged 21-65 years old was performed in urban Tianjin from April to October in 2013. The program included ThinPrep cytologic tests (TCT), HPV DNA detection and genotyping using nested polymerase chain reaction (PCR) combined with Pyrosequencing technology.

Making sense of intratumor genetic heterogeneity: altered frequency of androgen receptor CAG repeat length variants in breast cancer tissues.

To examine the significance of intratumor genetic heterogeneity (ITGH) of the androgen receptor (AR) gene in breast cancer, patient-matched samples of laser capture microdissected breast tumor cells, adjacent normal breast epithelia cells, and peripheral blood leukocytes were sequenced using a novel next generation sequencing protocol. This protocol measured the frequency of distribution of a variable AR CAG repeat length, a functional polymorphism associated with breast cancer risk. All samples exhibited some degree of ITGH with up to 30 CAG repeat length variants identified.

Deep sequencing of the hepatitis B virus in hepatocellular carcinoma patients reveals enriched integration events, structural alterations and sequence variations.

Chronic hepatitis B virus (HBV) infection is epidemiologically associated with hepatocellular carcinoma (HCC), but its role in HCC remains poorly understood due to technological limitations. In this study, we systematically characterize HBV in HCC patients. HBV sequences were enriched from 48 HCC patients using an oligo-bead-based strategy, pooled together and sequenced using the FLX-Genome-Sequencer.

Whole-genome sequencing of the efficient industrial fuel-ethanol fermentative Saccharomyces cerevisiae strain CAT-1.

The Saccharomyces cerevisiae strains widely used for industrial fuel-ethanol production have been developed by selection, but their underlying beneficial genetic polymorphisms remain unknown. Here, we report the draft whole-genome sequence of the S. cerevisiae strain CAT-1, which is a dominant fuel-ethanol fermentative strain from the sugarcane industry in Brazil.

The shaping of modern human immune systems by multiregional admixture with archaic humans.

Whole genome comparisons identified introgression from archaic to modern humans. Our analysis of highly polymorphic human leukocyte antigen (HLA) class I, vital immune system components subject to strong balancing selection, shows how modern humans acquired the HLA-B*73 allele in west Asia through admixture with archaic humans called Denisovans, a likely sister group to the Neandertals. Virtual genotyping of Denisovan and Neandertal genomes identified archaic HLA haplotypes carrying functionally distinctive alleles that have introgressed into modern Eurasian and Oceanian populations.

Although divergent in residues of the peptide binding site, conserved chimpanzee Patr-AL and polymorphic human HLA-A*02 have overlapping peptide-binding repertoires.

Patr-AL is an expressed, non-polymorphic MHC class I gene carried by ∼50% of chimpanzee MHC haplotypes. Comparing Patr-AL(+) and Patr-AL(-) haplotypes showed Patr-AL defines a unique 125-kb genomic block flanked by blocks containing classical Patr-A and pseudogene Patr-H. Orthologous to Patr-AL are polymorphic orangutan Popy-A and the 5' part of human pseudogene HLA-Y, carried by ∼10% of HLA haplotypes.

High-fidelity gene synthesis by retrieval of sequence-verified DNA identified using high-throughput pyrosequencing.

The construction of synthetic biological systems involving millions of nucleotides is limited by the lack of high-quality synthetic DNA. Consequently, the field requires advances in the accuracy and scale of chemical DNA synthesis and in the processing of longer DNA assembled from short fragments. Here we describe a highly parallel and miniaturized method, called megacloning, for obtaining high-quality DNA by using next-generation sequencing (NGS) technology as a preparative tool.

Pyrosequencing enhancement for better detection limit and sequencing homopolymers.

Pyrosequencing is a DNA sequencing technique based on sequencing-by-synthesis enabling rapid and real-time sequence determination. Although ample genomic research has been undertaken using pyrosequencing, the requirement of relatively high amount of DNA template and the difficulty in sequencing the homopolymeric regions limit its key advantages in the applications directing towards clinical research. In this study, we demonstrate that pyrosequencing on homopolymeric regions with 10 identical nucleotides can be successfully performed with optimal amount of DNA (0.

Nucleic acid template and the risk of a PCR-Induced HIV-1 drug resistance mutation.

Background: The HIV-1 nucleoside RT inhibitor (NRTI)-resistance mutation, K65R confers intermediate to high-level resistance to the NRTIs abacavir, didanosine, emtricitabine, lamivudine, and tenofovir; and low-level resistance to stavudine. Several lines of evidence suggest that K65R is more common in HIV-1 subtype C than subtype B viruses.

Methods And Findings: We performed ultra-deep pyrosequencing (UDPS) and clonal dideoxynucleotide sequencing of plasma virus samples to assess the prevalence of minority K65R variants in subtype B and C viruses from untreated individuals.

Six RNA viruses and forty-one hosts: viral small RNAs and modulation of small RNA repertoires in vertebrate and invertebrate systems.

We have used multiplexed high-throughput sequencing to characterize changes in small RNA populations that occur during viral infection in animal cells. Small RNA-based mechanisms such as RNA interference (RNAi) have been shown in plant and invertebrate systems to play a key role in host responses to viral infection. Although homologs of the key RNAi effector pathways are present in mammalian cells, and can launch an RNAi-mediated degradation of experimentally targeted mRNAs, any role for such responses in mammalian host-virus interactions remains to be characterized.

High throughput sequencing reveals a complex pattern of dynamic interrelationships among human T cell subsets.

Developing T cells face a series of cell fate choices in the thymus and in the periphery. The role of the individual T cell receptor (TCR) in determining decisions of cell fate remains unresolved. The stochastic/selection model postulates that the initial fate of the cell is independent of TCR specificity, with survival dependent on additional TCR/coreceptor "rescue" signals.

Minority variants associated with transmitted and acquired HIV-1 nonnucleoside reverse transcriptase inhibitor resistance: implications for the use of second-generation nonnucleoside reverse transcriptase inhibitors.

Objectives: K103N, the most common nonnucleoside reverse transcriptase inhibitor (NNRTI)-resistant mutation in patients with transmitted resistance and in patients receiving a failing NNRTI-containing regimen, is fully susceptible to the new NNRTI, etravirine. Therefore, we sought to determine how often NNRTI-resistant mutations other than K103N occur as minority variants in plasma samples for which standard genotypic resistance testing detects K103N alone.

Methods: We performed ultradeep pyrosequencing (UDPS; 454 Life Sciences a Roche Company, Branford, CT) of plasma virus samples from 13 treatment-naive and 20 NNRTI-experienced patients in whom standard genotypic resistance testing revealed K103N but no other major NNRTI-resistance mutations.

Ultra-deep pyrosequencing of hepatitis B virus quasispecies from nucleoside and nucleotide reverse-transcriptase inhibitor (NRTI)-treated patients and NRTI-naive patients.

The dynamics of emerging nucleoside and nucleotide reverse-transcriptase inhibitor (NRTI) resistance in hepatitis B virus (HBV) are not well understood because standard dideoxynucleotide direct polymerase chain reaction (PCR) sequencing assays detect drug-resistance mutations only after they have become dominant. To obtain insight into NRTI resistance, we used a new sequencing technology to characterize the spectrum of low-prevalence NRTI-resistance mutations in HBV obtained from 20 plasma samples from 11 NRTI-treated patients and 17 plasma samples from 17 NRTI-naive patients, by using standard direct PCR sequencing and ultra-deep pyrosequencing (UDPS). UDPS detected drug-resistance mutations that were not detected by PCR in 10 samples from 5 NRTI-treated patients, including the lamivudine-resistance mutation V173L (in 5 samples), the entecavir-resistance mutations T184S (in 2 samples) and S202G (in 1 sample), the adefovir-resistance mutation N236T (in 1 sample), and the lamivudine and adefovir-resistance mutations V173L, L180M, A181T, and M204V (in 1 sample).

Minority human immunodeficiency virus type 1 variants in antiretroviral-naive persons with reverse transcriptase codon 215 revertant mutations.

T215 revertant mutations such as T215C/D/E/S that evolve from the nucleoside reverse transcriptase (RT) inhibitor mutations T215Y/F have been found in about 3% of human immunodeficiency virus type 1 (HIV-1) isolates from newly diagnosed HIV-1-infected persons. We used a newly developed sequencing method-ultradeep pyrosequencing (UDPS; 454 Life Sciences)--to determine the frequency with which T215Y/F or other RT inhibitor resistance mutations could be detected as minority variants in samples from untreated persons that contain T215 revertants ("revertant" samples) compared with samples from untreated persons that lack such revertants ("control" samples). Among the 22 revertant and 29 control samples, UDPS detected a mean of 3.

High throughput automated allele frequency estimation by pyrosequencing.

Pyrosequencing is a DNA sequencing method based on the principle of sequencing-by-synthesis and pyrophosphate detection through a series of enzymatic reactions. This bioluminometric, real-time DNA sequencing technique offers unique applications that are cost-effective and user-friendly. In this study, we have combined a number of methods to develop an accurate, robust and cost efficient method to determine allele frequencies in large populations for association studies.

Viral population estimation using pyrosequencing.

The diversity of virus populations within single infected hosts presents a major difficulty for the natural immune response as well as for vaccine design and antiviral drug therapy. Recently developed pyrophosphate-based sequencing technologies (pyrosequencing) can be used for quantifying this diversity by ultra-deep sequencing of virus samples. We present computational methods for the analysis of such sequence data and apply these techniques to pyrosequencing data obtained from HIV populations within patients harboring drug-resistant virus strains.

Human papillomavirus (HPV), DNA aberrations and cell cycle progression in anal squamous cell carcinoma patients.

Unlabelled: Human papillomavirus (HPV) infections of the genital tract are sexually transmitted and prevalent worldwide. In this study, the role of HPV in 72 patients with anal squamous cell carcinoma was investigated.

Patients And Methods: Polymerase chain reaction (PCR) in combination with in situ hybridization was used to identify HPV-DNA in the patients' biopsies.

Pyrosequencing for discovery and analysis of DNA sequence variations.

Since the invention of pyrosequencing, more than 500 articles have been published describing different applications of this technology, most notably for DNA structure variation and microbial detection. Technological advances have been made to enhance the robustness and accuracy of this technique as well as to reduce the cost and increase the throughput. This review intends to cover recent advances in this technology and discuss its application for low and high-throughput DNA variation studies.

A pyrosequencing-tailored nucleotide barcode design unveils opportunities for large-scale sample multiplexing.

Multiplexed high-throughput pyrosequencing is currently limited in complexity (number of samples sequenced in parallel), and in capacity (number of sequences obtained per sample). Physical-space segregation of the sequencing platform into a fixed number of channels allows limited multiplexing, but obscures available sequencing space. To overcome these limitations, we have devised a novel barcoding approach to allow for pooling and sequencing of DNA from independent samples, and to facilitate subsequent segregation of sequencing capacity.

Does HPV-status 6-12 months after treatment of high grade dysplasia in the uterine cervix predict long term recurrence?

Background: Women once treated for high grade cervical dysplasia have a high long term risk for developing new dysplasia or cancer.

Objectives: To investigate if human papilloma virus (HPV)-negativity after treatment of cervical dysplasia reduces the need for frequent long term follow up.

Design: Case/control study based on archival smears.

Characterization of mutation spectra with ultra-deep pyrosequencing: application to HIV-1 drug resistance.

The detection of mutant spectra within a population of microorganisms is critical for the management of drug-resistant infections. We performed ultra-deep pyrosequencing to detect minor sequence variants in HIV-1 protease and reverse transcriptase (RT) genes from clinical plasma samples. We estimated empirical error rates from four HIV-1 plasmid clones and used them to develop a statistical approach to distinguish authentic minor variants from sequencing errors in eight clinical samples.