The hepatocyte traffic network in the human hepatitis A virus biological cycle from an evolutionary perspective.

Hepatitis A virus (HAV) egresses from hepatocytes cloaked in exosomes (eHAV). However, the traffic network used for its release from polarized hepatocytes is not completely understood. We propose that eHAV biogenesis may follow not only an ESCRT-mediated pathway but also the syndecan-syntenin-ALIX pathway.

Immunogenic Properties of a Novel Hepatitis A Vaccine Candidate Based on a Fast-Growing Viral Strain.

Background/objectives: Hepatitis A virus (HAV) yearly causes over 150 million new infections and around 40,000 deaths. Current vaccines are based on strains that grow poorly in cell culture, leading to high production costs and limited availability. This study aimed to compare the immunogenic properties of a novel HAV vaccine candidate based on the fast-growing HM175-HP strain with those of the parental slow-growing HM175-L0 strain, which derives from the cytopathic HM175 strain, like the prototype strain used in certain existing vaccines.

Dynamics of SARS-CoV-2 Alpha (B.1.1.7) variant spread: The wastewater surveillance approach.

Wastewater based epidemiology (WBE) offers an overview of the SARS-CoV-2 variants circulating among the population thereby serving as a proper surveillance method. The variant of concern (VOC) Alpha was first identified in September 2020 in the United Kingdom, and rapidly became dominant across Europe. Our objective was to elucidate the Alpha VOC outcompetition rate and identify mutations in the spike glycoprotein (S) gene, indicative of the circulation of the Alpha VOC and/or other variants in the population through wastewater analysis.

Time Evolution of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Wastewater during the First Pandemic Wave of COVID-19 in the Metropolitan Area of Barcelona, Spain.

Two large wastewater treatment plants (WWTP), covering around 2.7 million inhabitants, which represents around 85% of the metropolitan area of Barcelona, were sampled before, during, and after the implementation of a complete lockdown. Five one-step reverse transcriptase quantitative PCR (RT-qPCR) assays, targeting the polymerase (IP2 and IP4), the envelope (E), and the nucleoprotein (N1 and N2) genome regions, were employed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA detection in 24-h composite wastewater samples concentrated by polyethylene glycol (PEG) precipitation.

Investigation on the Evolution of Shiga Toxin-Converting Phages Based on Whole Genome Sequencing.

Bacteriophages are pivotal elements in the dissemination of virulence genes. The main virulence determinants of Shiga Toxin producing , Shiga Toxins (Stx), are encoded by genes localized in the genome of lambdoid bacteriophages. Stx comprise two antigenically different types, Stx1 and Stx2, further divided into subtypes.