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613 result(s) for "Hepatovirus A"
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A novel hepatovirus identified in wild woodchuck Marmota himalayana
Hepatitis A virus (HAV) is a hepatotropic picornavirus that causes acute liver disease worldwide. Here, we report on the identification of a novel hepatovirus tentatively named Marmota Himalayana hepatovirus (MHHAV) in wild woodchucks ( Marmota Himalayana) in China. The genomic and molecular characterization of MHHAV indicated that it is most closely related genetically to HAV. MHHAV has wide tissue distribution but shows tropism for the liver. The virus is morphologically and structurally similar to HAV. The pattern of its codon usage bias is also consistent with that of HAV. Phylogenetic analysis indicated that MHHAV groups with known HAVs but forms an independent branch and represents a new species in the genus Hepatovirus within the family Picornaviridae . Antigenic site analysis suggested MHHAV has a new antigenic property to other HAVs. Further evolutionary analysis of MHHAV and primate HAVs led to a most recent common ancestor estimate of 1,000 years ago, while the common ancestor of all HAV-related viruses including phopivirus can be traced back to 1800 years ago. The discovery of MHHAV may provide new insights into the origin and evolution of HAV and a model system with which to explore the pathogenesis of HAV infection.
Discovery of a Novel Hepatovirus ( Phopivirus of Seals) Related to Human Hepatitis A Virus
Describing the viral diversity of wildlife can provide interesting and useful insights into the natural history of established human pathogens. In this study, we describe a previously unknown picornavirus in harbor seals (tentatively named phopivirus) that is related to human hepatitis A virus (HAV). We show that phopivirus shares several genetic and phenotypic characteristics with HAV, including phylogenetic relatedness across the genome, a specific and seemingly quiescent tropism for hepatocytes, structural conservation in a key functional region of the type III internal ribosomal entry site (IRES), and a codon usage bias consistent with that of HAV. IMPORTANCE Hepatitis A virus (HAV) is an important viral hepatitis in humans because of the substantial number of cases each year in regions with low socioeconomic status. The origin of HAV is unknown, and no nonprimate HAV-like viruses have been described. Here, we describe the discovery of an HAV-like virus in seals. This finding suggests that the diversity and evolutionary history of these viruses might be far greater than previously thought and may provide insight into the origin and pathogenicity of HAV. Hepatitis A virus (HAV) is an important viral hepatitis in humans because of the substantial number of cases each year in regions with low socioeconomic status. The origin of HAV is unknown, and no nonprimate HAV-like viruses have been described. Here, we describe the discovery of an HAV-like virus in seals. This finding suggests that the diversity and evolutionary history of these viruses might be far greater than previously thought and may provide insight into the origin and pathogenicity of HAV.
Quantitative PCR-based identification of enteric viruses contaminating fresh produce and surface water used for irrigation in Egypt
Fresh produce irrigated with surface water that may contain pathogens such as enteric viruses can lead to outbreaks of foodborne viral illnesses. In the current study, we performed real-time PCR (qPCR) to monitor the presence of enteric viruses such as human adenoviruses (HAdVs), hepatitis A virus (HAV), rotavirus group A (RVA), and norovirus GI (NoV GI) in surface water and fresh produce that were grown using this surface water in Egypt. Samples were collected on four occasions from different sites located in the Delta and in Greater Cairo, Egypt. Of the 32 water samples and 128 fresh produce samples, 27/32 (84.3%) and 99/128 (77.3%), respectively, were positive for at least one virus. HAdV (30/32) with a mean viral load = 1.5 × 10 7 genome copies/L (GC/L) was the most commonly detected virus in water, followed by RVA (16/32, with a mean viral load = 2.7 × 10 5 GC/L), HAV (11/32, with a mean viral load = 1.2 × 10 4 GC /L), and NoV GI (10/32, with a mean viral load = 3.5 × 10 3 GC/L). Additionally, HAdV (71/128, with a mean viral load = 9.8 × 10 5 GC/g) was also the most commonly detected virus in the fresh produce, followed by NoV GI (43/128, with a mean viral load = 4.5 × 10 3 GC/g), HAV (33/128, with a mean viral load = 6.4 × 10 3 GC/g), and RVA (25/128, with a mean viral load = 1.5 × 10 4 GC/g). Our results indicate that fresh produce may be contaminated with a wide range of enteric viruses, and these viruses may originate from virus-contaminated irrigation water. Moreover, this fresh produce may serve as a potential vector for the transmission of viral foodborne illnesses. These findings are important for future risk assessment analysis related to water/foodborne viruses. Graphical abstract . Please provide caption for Graphical AbstractGraphical abstract showing sample collection and processing
A pathogenic picornavirus acquires an envelope by hijacking cellular membranes
Hepatitis A virus particles released from cells can hijack and become wrapped in host-derived membranes by using proteins that facilitate the budding of many enveloped viruses, calling into question the traditional distinction between enveloped and non-enveloped viruses. Viral envelopes made with host-cell proteins This study of hepatitis A virus (HAV) challenges a basic tenet in virology, the classic distinction between 'enveloped' and 'non-enveloped' viruses. HAV, a picornavirus consisting of a single-stranded RNA packaged in a protein shell, is classified as a non-enveloped virus, lacking a lipid-bilayer membrane. Stanley Lemon and colleagues now show that HAV particles released from cells can co-opt the ESCRT (endosomal sorting-complexes required for transport) machinery, becoming cloaked in host-derived membranes. HAV's hijacked envelope may facilitate the virus's spread within the liver, but could also explain how passive transfer of antibody works as post-exposure prophylaxis of hepatitis A, a phenomenon that has been known clinically for decades but has not been explained. Animal viruses are broadly categorized structurally by the presence or absence of an envelope composed of a lipid-bilayer membrane 1 , attributes that profoundly affect stability, transmission and immune recognition. Among those lacking an envelope, the Picornaviridae are a large and diverse family of positive-strand RNA viruses that includes hepatitis A virus (HAV), an ancient human pathogen that remains a common cause of enterically transmitted hepatitis 2 , 3 , 4 . HAV infects in a stealth-like manner and replicates efficiently in the liver 5 . Virus-specific antibodies appear only after 3–4 weeks of infection, and typically herald its resolution 3 , 4 . Although unexplained mechanistically, both anti-HAV antibody and inactivated whole-virus vaccines prevent disease when administered as late as 2 weeks after exposure 6 , when virus replication is well established in the liver 5 . Here we show that HAV released from cells is cloaked in host-derived membranes, thereby protecting the virion from antibody-mediated neutralization. These enveloped viruses (‘eHAV’) resemble exosomes 7 , small vesicles that are increasingly recognized to be important in intercellular communications. They are fully infectious, sensitive to extraction with chloroform, and circulate in the blood of infected humans. Their biogenesis is dependent on host proteins associated with endosomal-sorting complexes required for transport (ESCRT) 8 , namely VPS4B and ALIX. Whereas the hijacking of membranes by HAV facilitates escape from neutralizing antibodies and probably promotes virus spread within the liver, anti-capsid antibodies restrict replication after infection with eHAV, suggesting a possible explanation for prophylaxis after exposure. Membrane hijacking by HAV blurs the classic distinction between ‘enveloped’ and ‘non-enveloped’ viruses and has broad implications for mechanisms of viral egress from infected cells as well as host immune responses.
Identification and Genomic Characterization of Two Novel Hepatoviruses in Shrews from Yunnan Province, China
Hepatitis A virus (HAV), a member of the genus Hepatovirus (Picornaviridae HepV), remains a significant viral pathogen, frequently causing enterically transmitted hepatitis worldwide. In this study, we conducted an epidemiological survey of HepVs carried by small terrestrial mammals in the wild in Yunnan Province, China. Utilizing HepV-specific broad-spectrum RT-PCR, next-generation sequencing (NGS), and QNome nanopore sequencing (QNS) techniques, we identified and characterized two novel HepVs provisionally named EpMa-HAV and EpLe-HAV, discovered in the long-tailed mountain shrew (Episoriculus macrurus) and long-tailed brown-toothed shrew (Episoriculus leucops), respectively. Our sequence and phylogenetic analyses of EpMa-HAV and EpLe-HAV indicated that they belong to the species Hepatovirus I (HepV-I) clade II, also known as the Chinese shrew HepV clade. Notably, the codon usage bias pattern of novel shrew HepVs is consistent with that of previously identified Chinese shrew HepV. Furthermore, our structural analysis demonstrated that shrew HepVs differ from other mammalian HepVs in RNA secondary structure and exhibit variances in key protein sites. Overall, the discovery of two novel HepVs in shrews expands the host range of HepV and underscores the existence of genetically diverse animal homologs of human HAV within the genus HepV.
Microbiological Contaminants in Drinking Water: Current Status and Challenges
Water is a vital resource to every living thing on the earth. Once the water is contaminated (physically, chemically, biologically, or radiologically), it brought negative impacts to the living thing. This paper provides a brief review of the characterization of biological pollutants in drinking water and their effects on human health. Some biological contamination was detected in water resources such as pathogenic bacteria (Escherichia coli, Vibrio cholerae, Salmonella, etc.), viruses (hepatitis A virus, hepatitis E virus, rotavirus, etc.), parasites (Giardia, Entamoeba, Cyclospora, etc.), and parasitic worm (Ascaris lumbricoides, Ancylostoma duodenale, Strongyloides stercoralis, etc.). The diseases were significantly prevalent in developing countries due to limited access to clean water and poor sanitation. Most of the diseases had common symptoms such as diarrhea, fever, and body and muscle aches that were transmitted to humans through the fecal–oral route. About 1.7 billion children were affected by diarrhea each year and about 525,000 of the children died each year. Besides, nearly 1 million adults were killed by diarrhea every year. Some treatment was implemented to remove the biological contamination in drinking water, such as oxidation treatment, ultraviolet radiation, distillation, biologically active carbon filtration, electrochemical, and nanotechnology.