Shotgun metagenomics by high-throughput sequencing may allow deep and accurate characterization of host-associated total microbiomes, including bacteria, viruses, protists and fungi. However, the ...analysis of such sequencing data is still extremely challenging in terms of both overall accuracy and computational efficiency, and current methodologies show substantial variability in misclassification rate and resolution at lower taxonomic ranks or are limited to specific life domains (e.g. only bacteria). We present here MetaShot, a workflow for assessing the total microbiome composition from host-associated shotgun sequence data, and show its overall optimal accuracy performance by analyzing both simulated and real datasets.
https://github.com/bfosso/MetaShot.
graziano.pesole@uniba.it.
Supplementary data are available at Bioinformatics online.
•NGS based method was evaluated against standard diagnostic assay for HCV genotyping.•Assigned subtypes for genotype 2 and 4 increased significantly.•Subtyping for genotype 1 and 3 did not show ...significant divergence.•The assay is suitable for diagnostic use with routinely methods.•The NGS based method is the unique CE-IVD marked assay for HCV genotyping.
Chronic HCV infection is one of the leading causes of liver-related death and in many countries it is a primary reason for having a liver transplant. HCV genotype identification has long been used in the clinical practice, since different genotypes have different response rates and required different doses and durations of IFN/RBV treatment; moreover both the frequency and the pattern of resistance to different Direct-Acting Antivirals (DAAs) classes are subtype specific. Hence the necessity to make an accurate HCV subtyping becomes a fundamental tool to optimize current and future clinical management of HCV infected subjects. In the present study the performance of a next generation sequencing (NGS: based on the Ion Torrent Platform-Vela Sentosa SQ 301 sequencer) HCV genotyping assay has been evaluated. The current method targets a region of the NS5B gene and it is the unique NGS based market CE-IVD assay. As a comparative method a commercial method based on the detection via reverse hybridization of 5′UTR and core regions (Versant HCV Genotype 2.0 Assay, LiPA, Siemens) was selected. A total 207 plasma samples from HCV infected individuals were used. No selection was made for these samples that were submitted for routine HCV genotyping. The results show Vela NGS assay assigns major number of HCV subtypes with respect LiPA. Concerning genotype 1 and 3, the discrepancy of assigned subtypes for LiPA with respect to Vela NGS assay is not relevant (1.8% and 2%, respectively); in contrast, the difference of assigned subtypes for genotypes 2 and 4 is very high (96.6% and 100%, respectively). The resistance mutations data, except for 1a and 1b subtypes, remain scarce; the future relevant challenge will be to identify subtypes-specific drug resistance mutations, which are essential to create highly personalized therapeutic pathways.
Background/Aims: Hepatitis C virus (HCV) infection results in a high frequency of chronic disease. The aim of this study was to identify early prognostic markers of disease resolution by performing a ...comprehensive analysis of viral and host factors during the natural course of acute HCV infection. Methods: The clinical course of acute hepatitis C was determined in 34 consecutive patients. Epidemiological and virological parameters, as well as cell mediated immunity (CMI) and distribution of human leukocyte antigens (HLA) alleles were analysed. Results: Ten out of 34 patients experienced self-limiting infection, with most resolving patients showing fast kinetics of viral clearance: at least one negative HCV RNA test during this phase predicted a favourable outcome. Among other clinical epidemiological parameters measured, the self-limiting course was significantly associated with higher median peak bilirubin levels at the onset of disease, and with the female sex, but only the latter parameter was independently associated after multivariate analysis. No significant differences between self-limiting or chronic course were observed for the distribution of DRB1 and DQB1 alleles. HCV specific T cell response was more frequently detected during acute HCV infection, than in patients with chronic HCV disease. A significantly broader T cell response was found in patients with self-limiting infection than in those with chronic evolving acute hepatitis C. Conclusion: The results suggest that host related factors, in particular sex and CMI, play a crucial role in the spontaneous clearance of this virus. Most importantly, a negative HCV RNA test and broad CMI within the first month after onset of the symptoms represent very efficacious predictors of viral clearance and could thus be used as criteria in selecting candidates for early antiviral treatment.
The objective of this study is to identify a simplified rapid screening and linkage-to-care model for HCV among PWUD.
The study stems from a collaborative project bringing together two local Italian ...Centers for Drug Addiction and the Hepatology-Infectious Diseases Department of Lazzaro Spallanzani. A research physician analyzed the available medical records seeking to identify HCV and HIV infected patients in care in the addiction centers. Between March 2018 and January 2020 subjects were selected from among a cohort of 720 PWUD in the two Centers' care. The study comprises three steps: first, screening for HCVAb; second, the linkage to care; third, clinical assessment to treatment. The research physician recruited patients for the first two steps directly in their local addiction center. The third step was conducted in the Spallanzani. The characteristics of those subjects who adhered to the three-step study program were then compared to those of the non-adhering PWUD.
194 were known HCVAb positive patients. Of the 505 PWUD in the care of the two Centers eligible for screening, 364 were enrolled in the study. 144 resulted HCVAb positive. 269 were tested for HCVRNA. 101 underwent a full assessment. 96 patients started antiviral therapy with DAA. Patients who refused first step screening were older patients and mainly heroin users; in the second step, almost all the HIV/HCV co-infected patients agreed to a viremia test; in the third step all the HIV/HCV co-infected patients refused HCV treatment.
The study suggests an on-site specialist approach conducted directly in the addiction centers themselves starting from screening; it can bring the goal of HCV PWUD microelimination closer.
Summary
What is known and objective
The second‐generation direct‐acting antivirals represented the first major turning point for the eradication of HCV infection in almost all settings of patients. ...However, no data were available on use in gastro‐resected patients.
Case description
We report on a gastrectomized patient with chronic hepatitis C infection. She was treated with sofosbuvir and ledipasvir (SOF/LDV) for 12 weeks, with measurement of blood levels of the drugs. She obtained sustained virological response at week 12 and 24 without dose adjustment.
What is new and conclusion
This case report can provide information useful for clinical practice in this set of patients and can open new perspectives in evaluating actual SOF/LDV bioavailability.
We describe the first reported case of treatment with direct antiviral agents in a gastrotomized patient. This report can provide information useful for clinical practice in this set of patients and can open new perspectives in evaluating Sofosbuvir/Ledipasvir bioavailability.
During 2011, 5 persons in the area of Lazio, Italy were infected with a monophyletic strain of hepatitis E virus that showed high sequence homology with isolates from swine in China. Detection of ...this genotype in Italy parallels findings in other countries in Europe, signaling the possible spread of strains new to Western countries.
Background and aims: Cellular mediated immunity (CMI) is thought to play a key role in resolution of primary hepatitis C virus (HCV) infection. However, CD4+ and CD8+ T cell responses are also ...generated during acute infection in individuals who become chronic, suggesting that they developed a defective CMI. The aim of this study was to verify if and when such immune dysfunction is established by measuring the breadth, magnitude, function, and duration of CMI in a large cohort of subjects during the natural course of acute HCV infection. Methods: CMI was comprehensively studied by prospective sampling of 31 HCV acutely infected subjects enrolled at the onset of infection and followed for a median period of one year. Results: Our results indicated that while at the onset of acute HCV infection a measurable CMI with effector function was detected in the majority of subjects, after approximately six months less than 10% of chronically infected individuals displayed significant CMI compared with 70% of subjects who cleared the virus. We showed that progressive disappearance of HCV specific T cells from the peripheral blood of chronic patients was due to an impaired ability to proliferate that could be rescued in vitro by concomitant exposure to interleukin 2 and the antigen. Conclusion: Our data provide evidence of strong and multispecific T cell responses with a sustained ability to proliferate in response to antigen stimulation as reliable pharmacodynamic measures of a protective CMI during acute infection, and suggest that early impairment of proliferation may contribute to loss of T cell response and chronic HCV persistence.
The efficacy of direct-acting antivirals (DAAs) depends on the hepatitis C virus (HCV) genotype 4 (GT4) subtype which are used in the treatment of HCV. We aimed to retrospectively investigate the ...baseline prevalence of HCV NS5A and NS5B polymorphisms and their impact on virological outcome in GT4-infected patients treated with various DAA regimens.
Available plasma samples from HCV GT4-infected patients treated with different DAA regimens were analyzed at baseline and after treatment failure, where applicable. Sanger sequencing of patient-derived NS5A and NS5B regions was performed on all available samples, while ultradeep pyrosequencing (UDPS) of NS5A and NS5B regions was performed only on samples from treatment failures at different time points.
Sustained virological response (SVR) was achieved by 96% (48/50) of patients. Of 16 patients with baseline NS5A sequence, polymorphisms at amino acid positions associated with drug resistance were detected only at position 58: P58 (69.2%) and T58 (30.8%). Of 21 patients with baseline NS5B sequence, N142S was detected only in the two treatment failures, both with GT4d were treated with sofosbuvir (SOF)-based regimens, suggesting a potential involvement in SOF efficacy. Two patients (patient 1 Pt1 and patient 2 Pt2) relapsed. In Pt1, NS5A-T56I and NS5A-Y93H/S emerged. In Pt2, NS5A-L28F emerged and a novel NS5B resistance-associated substitution (RAS), L204F, representing 1.5% of the viral population at baseline, enriched to 71% and 91.6% during and after treatment failure, respectively. UDPS of NS5B from Pt2 indicated a mixed infection of approximately 1:5, GT1a:GT4d, at baseline and GT4d during failure. Phylogenetic analysis of NS5A sequences indicated no clustering of HCV strains from patients achieving SVR vs patients who relapsed. The mean genetic distance in NS5A sequences was 5.8%, while a lower genetic distance (3.1%) was observed in NS5B sequences.
Results from these analyses confirm the importance of UDPS in the analysis of viral quasispecies variability and the identification of novel RASs potentially associated with DAA treatment failure in HCV GT4-infected patients.
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