Comparison of the Idylla™ Respiratory (IFV-RSV) panel with the GeneXpert Xpert® Flu/RSV assay: a retrospective study with nasopharyngeal and midturbinate samples.

The objective of this study was to compare the performance of the Idylla™ Respiratory (IFV-RSV) panel to the GeneXpert Xpert® Flu/RSV assay and establish the performance of a midturbinate swab compared to nasopharyngeal sampling. Considering GeneXpert® assay as imperfect reference standard, a positive percentage agreement between both assays of 98-100% for influenza A and 96-99% for influenza B could be calculated when 354 nasopharyngeal and 325 midturbinate swabs were retrospectively analyzed. Comparing midturbinate samples to nasopharyngeal specimens of 321 subjects, positive percentage agreement varied from 42% to 94% depending on both target virus and assay used.

Amplification and sequencing of the hepatitis C virus NS3/4A protease and the NS5B polymerase regions for genotypic resistance detection of clinical isolates of subtypes 1a and 1b.

Genotypic testing based on subtype-specific amplification and population Sanger sequencing for two nonstructural (NS) protein-coding regions, the NS3/4A protease and the NS5B polymerase, of the hepatitis C virus (HCV) genome is described here. The protocols include the molecular steps for RNA extraction, one-step RT-PCR followed by inner PCR and population Sanger sequencing, to obtain the sequence information of the target regions from the clinical isolates of HCV subtypes 1a and 1b, which can be used to detect any sequence change in the viral genome as for example caused by the development of drug resistance in these two common viral targets.

A cellular replicon-based phenotyping assay to determine susceptibility of hepatitis C virus clinical isolates to NS3/4A protease inhibitors.

A hepatitis C virus (HCV) replicon-based protease phenotyping assay has been developed that allows determining the susceptibility of a patient's HCV protease sequence to HCV protease inhibitors. In brief, HCV protease sequences amplified from clinical samples are cloned in a transient HCV genotype 1b replicon backbone, containing a luciferase reporter gene. These protease chimeric replicons are replication-competent when electroporated into susceptible Huh7-Lunet cells.

Development and evaluation of an automated hepatitis C virus NS5B sequence-based subtyping assay.

Background: Hepatitis C virus (HCV) genotyping and accurate subtype determination is becoming increasingly important to better understand viral evolution, the development of resistance to STAT-C, and possibly even for the treatment and management of chronic HCV-infected patients.

Methods: A subtyping assay based on a 329-bp sequence of the NS5B region, together with an automated subtype interpretation tool was developed. Clinical samples of the six major genotypes were used to assess assay performance characteristics.

Stop codon insertion restores the particle formation ability of hepatitis B virus core-hantavirus nucleocapsid protein fusions.

In recent years, epitopes of various origin have been inserted into the core protein of hepatitis B virus (HBc), allowing the formation of chimeric HBc particles. Although the C-terminus of a C-terminally truncated HBc (HBc) tolerates the insertion of extended foreign sequences, the insertion capacity is still a limiting factor for the construction of multivalent vaccines. Previously, we described a new system to generate HBc mosaic particles based on a read-through mechanism in an Escherichia coli suppressor strain [J Gen Virol 1997;78:2049-2053].

Inhibition of hepatitis B virus replication by drug-induced depletion of nucleocapsids.

Chronic hepatitis B virus (HBV) infection is a major cause of liver disease. Only interferon-alpha and the nucleosidic inhibitors of the viral polymerase, 3TC and adefovir, are approved for therapy. However, these therapies are limited by the side effects of interferon and the substantial resistance of the virus to nucleosidic inhibitors.