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Cell Jun 2022Soon after the emergence and global spread of the SARS-CoV-2 Omicron lineage BA.1, another Omicron lineage, BA.2, began outcompeting BA.1. The results of statistical...
Soon after the emergence and global spread of the SARS-CoV-2 Omicron lineage BA.1, another Omicron lineage, BA.2, began outcompeting BA.1. The results of statistical analysis showed that the effective reproduction number of BA.2 is 1.4-fold higher than that of BA.1. Neutralization experiments revealed that immunity induced by COVID vaccines widely administered to human populations is not effective against BA.2, similar to BA.1, and that the antigenicity of BA.2 is notably different from that of BA.1. Cell culture experiments showed that the BA.2 spike confers higher replication efficacy in human nasal epithelial cells and is more efficient in mediating syncytia formation than the BA.1 spike. Furthermore, infection experiments using hamsters indicated that the BA.2 spike-bearing virus is more pathogenic than the BA.1 spike-bearing virus. Altogether, the results of our multiscale investigations suggest that the risk of BA.2 to global health is potentially higher than that of BA.1.
Topics: Animals; COVID-19; Cricetinae; Epithelial Cells; Humans; SARS-CoV-2; Spike Glycoprotein, Coronavirus
PubMed: 35568035
DOI: 10.1016/j.cell.2022.04.035 -
Medicine (Abingdon, England : UK Ed.) Nov 2017This article reviews the virology, immunology and epidemiology of the most common viral causes of acute gastroenteritis (rotaviruses, human caliciviruses, astroviruses,... (Review)
Review
This article reviews the virology, immunology and epidemiology of the most common viral causes of acute gastroenteritis (rotaviruses, human caliciviruses, astroviruses, enteric adenoviruses). Clinical symptoms range from mild diarrhoea to life-threatening dehydration, and rotavirus disease is a major cause of childhood mortality, mainly in developing countries. The diagnosis, treatment and preventive measures are reviewed. Uncommon viral causes of acute gastroenteritis and viruses causing gastroenteritis in immunodeficient patients are also discussed. Two live attenuated rotavirus vaccines (Rotarix, RotaTeq) have been licensed in >100 countries since 2006 and used in universal mass vaccination (UMV) programmes. In addition, a new rotavirus vaccine was licensed in India in 2015 for UMV. Although rotavirus vaccines are highly effective in industrialized countries, they are less so in low-income countries of sub-Saharan Africa and South-East Asia. Vaccines against human norovirus disease are under development. Major progress has recently been made in basic research on rotaviruses and human caliciviruses.
PubMed: 32288581
DOI: 10.1016/j.mpmed.2017.08.005 -
Viruses Mar 2019Besides noroviruses, the family comprises four other accepted genera: , and . There are six new genera proposed: , and All have closely related genome structures, but... (Review)
Review
Besides noroviruses, the family comprises four other accepted genera: , and . There are six new genera proposed: , and All have closely related genome structures, but are genetically and antigenically highly diverse and infect a wide range of mammalian host species including humans. Recombination in nature is not infrequent for most of the , contributing to their diversity. Sapovirus infections cause diarrhoea in pigs, humans and other mammalian hosts. Lagovirus infections cause systemic haemorrhagic disease in rabbits and hares, and vesivirus infections lead to lung disease in cats, vesicular disease in swine, and exanthema and diseases of the reproductive system in large sea mammals. Neboviruses are an enteric pathogen of cattle, differing from bovine norovirus. At present, only a few selected caliciviruses can be propagated in cell culture (permanent cell lines or enteroids), and for most of the cultivatable caliciviruses helper virus-free, plasmid only-based reverse genetics systems have been established. The replication cycles of the caliciviruses are similar as far as they have been explored: viruses interact with a multitude of cell surface attachment factors (glycans) and co-receptors (proteins) for adsorption and penetration, use cellular membranes for the formation of replication complexes and have developed mechanisms to circumvent innate immune responses. Vaccines have been developed against lagoviruses and vesiviruses, and are under development against human noroviruses.
Topics: Animals; Caliciviridae; Caliciviridae Infections; Genome, Viral; Humans; Norovirus; Phylogeny; Sequence Analysis, DNA
PubMed: 30901945
DOI: 10.3390/v11030286 -
Uirusu Dec 2011Caliciviruses represented by norovirus and sapovirus exist not only in human but also in other animal species. Clinical manifestations are gastroenteritis, respiratory... (Review)
Review
Caliciviruses represented by norovirus and sapovirus exist not only in human but also in other animal species. Clinical manifestations are gastroenteritis, respiratory infections, vesicles and hemorrhagic skin diseases and others symptoms depended on the viruses. Inapparent symptom of calicivirus infection is also recognized. Calicivirus is stable in the environment and found sometimes in contaminated food or water sources. In addition to intragenomic mutation, intragenomic recombination is the common phenomenon that usually found in calicivirus genome. The genomic recombinations have been reported among the strains within the same animal species. For diagnosis and molecular epidemiological study, several laboratory methods are available, such as genetic molecular analysis, enzyme immunoassay and immunochromatography, which developed by using the antibody against virus-like particles. The reactivity between virus and host immunity is type specific and the titer of cross reaction is not so high. There are evidences that the new variant strains are emerged and spread quickly year by year. Histo-blood group antigen (HBGA) is one of the specific host cells receptor for calicivirus. Infectivity of the virus depends on specificity of the HBGA on the host cells. Because of the inability to culture human norovirus and sapovirus, pathogenesis and immunological data are limited. So far, only feline calicivirus and mouse norovirus are cultivable. Animal model studies for calicivirus by gnotobiotic pigs with human calicivirus and mouse with mouse norovirus are mainly used for experiments of pathobiological study, treatment and vaccine development.
Topics: Animals; Caliciviridae; Caliciviridae Infections; Gastroenteritis; Humans; Mice; Norovirus; Sapovirus; Viral Vaccines
PubMed: 22916566
DOI: 10.2222/jsv.61.193 -
Frontiers in Plant Science 2022
PubMed: 36161005
DOI: 10.3389/fpls.2022.1014516 -
Medicine (Abingdon, England : UK Ed.) Dec 2013This article reviews the virology, immunology and epidemiology of the most common viral causes of acute gastroenteritis (rotaviruses, human caliciviruses, astroviruses... (Review)
Review
This article reviews the virology, immunology and epidemiology of the most common viral causes of acute gastroenteritis (rotaviruses, human caliciviruses, astroviruses and enteric adenoviruses). The clinical symptoms span from mild diarrhoea to life-threatening dehydration, and rotavirus disease is a major cause of childhood mortality, mainly in developing countries. The diagnosis, treatment and preventive measures are reviewed. Uncommon viral causes of acute gastroenteritis and viruses causing gastroenteritis in immunodeficient patients are mentioned. The clinically most important development in this field over the past 3 years has been the wide application of the new live attenuated rotavirus vaccines in universal mass vaccination programmes in many countries.
PubMed: 32288575
DOI: 10.1016/j.mpmed.2013.09.009 -
Journal of Controlled Release :... Mar 2022Respiratory viruses have sometimes resulted in worldwide pandemics, with the influenza virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) being major... (Review)
Review
Respiratory viruses have sometimes resulted in worldwide pandemics, with the influenza virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) being major participants. Long-term efforts have made it possible to control the influenza virus, but seasonal influenza continues to take many lives each year, and a pandemic influenza virus sometimes emerges. Although vaccines for coronavirus disease 2019 (COVID-19) have been developed, we are not yet able to coexist with the SARS-CoV-2. To overcome such viruses, it is necessary to obtain knowledge about international surveillance systems, virology, ecology and to determine that immune responses are effective. The information must then be transferred to drugs. Delivery systems would be expected to contribute to the rational development of drugs. In this review, virologist and drug delivery system (DDS) researchers discuss drug delivery strategies, especially the use of lipid-based nanocarriers, for fighting to respiratory virus infections.
Topics: Drug Delivery Systems; Humans; Pandemics; SARS-CoV-2; Virus Diseases; COVID-19 Drug Treatment
PubMed: 35122872
DOI: 10.1016/j.jconrel.2022.01.046 -
Microbiology Spectrum Aug 2023Norovirus is the primary cause of viral gastroenteritis (GE). To investigate norovirus epidemiology, there is a need for whole-genome sequencing and reference sets...
Norovirus is the primary cause of viral gastroenteritis (GE). To investigate norovirus epidemiology, there is a need for whole-genome sequencing and reference sets consisting of complete genomes. To investigate the potential of shotgun metagenomic sequencing on the Illumina platform for whole-genome sequencing, 71 reverse transcriptase quantitative PCR (RT-qPCR) norovirus positive-feces (threshold cycle [], <30) samples from norovirus surveillance within The Netherlands were subjected to metagenomic sequencing. Data were analyzed through an in-house next-generation sequencing (NGS) analysis workflow. Additionally, we assessed the potential of metagenomic sequencing for the surveillance of off-target viruses that are of importance for public health, e.g., sapovirus, rotavirus A, enterovirus, parechovirus, aichivirus, adenovirus, and bocaparvovirus. A total of 60 complete and 10 partial norovirus genomes were generated, representing 7 genogroup I capsid genotypes and 12 genogroup II capsid genotypes. In addition to the norovirus genomes, the metagenomic approach yielded partial or complete genomes of other viruses for 39% of samples from children and 6.7% of samples from adults, including adenovirus 41 ( = 1); aichivirus 1 ( = 1); coxsackievirus A2 ( = 2), A4 ( = 2), A5 ( = 1), and A16 ( = 1); bocaparvovirus 1 ( = 1) and 3 ( = 1); human parechovirus 1 ( = 2) and 3 ( = 1); Rotavirus A ( = 1); and a sapovirus GI.7 ( = 1). The sapovirus GI.7 was initially not detected through RT-qPCR and warranted an update of the primer and probe set. Metagenomic sequencing on the Illumina platform robustly determines complete norovirus genomes and may be used to broaden gastroenteritis surveillance by capturing off-target enteric viruses. Viral gastroenteritis results in significant morbidity and mortality in vulnerable individuals and is primarily caused by norovirus. To investigate norovirus epidemiology, there is a need for whole-genome sequencing and reference sets consisting of full genomes. Using surveillance samples sent to the Dutch National Institute for Public Health and the Environment (RIVM), we compared metagenomics against conventional techniques, such as RT-qPCR and Sanger-sequencing, with norovirus as the target pathogen. We determined that metagenomics is a robust method to generate complete norovirus genomes, in parallel to many off-target pathogenic enteric virus genomes, thereby broadening our surveillance efforts. Moreover, we detected a sapovirus that was not detected by our validated gastroenteritis RT-qPCR panel, which exemplifies the strength of metagenomics. Our study shows that metagenomics can be used for public health gastroenteritis surveillance, the generation of reference-sets for molecular epidemiology, and how it compares to current surveillance strategies.
Topics: Child; Adult; Humans; Infant; Public Health; Metagenomics; RNA, Viral; Gastroenteritis; Rotavirus; Viruses; Enteritis; Enterovirus Infections; Adenoviridae Infections; Norovirus; Adenoviridae; Adenovirus Infections, Human; Sapovirus; Enterovirus; Feces
PubMed: 37432120
DOI: 10.1128/spectrum.05022-22 -
Medicine (Abingdon, England : UK Ed.) Nov 2009The virology, immunology, diagnosis, clinical symptoms, treatment, epidemiology and prevention measures relating to the most common viral causes of acute gastroenteritis... (Review)
Review
The virology, immunology, diagnosis, clinical symptoms, treatment, epidemiology and prevention measures relating to the most common viral causes of acute gastroenteritis (rotaviruses, human caliciviruses, astroviruses and enteric adenoviruses) are briefly reviewed. Uncommon viral causes of acute gastroenteritis and viruses causing gastroenteritis in immunodeficient patients are mentioned. The main change over the past three years has been the development, licensing and wide application of new live attenuated rotavirus vaccines.
PubMed: 32288569
DOI: 10.1016/j.mpmed.2009.08.005 -
Animal Diseases 2021Bile acids (BAs) are evolutionally conserved molecules synthesized in the liver from cholesterol to facilitating the absorption of fat-soluble nutrients. In the... (Review)
Review
Bile acids (BAs) are evolutionally conserved molecules synthesized in the liver from cholesterol to facilitating the absorption of fat-soluble nutrients. In the intestines, where enteric viruses replicate, BAs also act as signaling molecules that modulate various biological functions activation of specific receptors and cell signaling pathways. To date, BAs present either pro-viral or anti-viral effects for the replication of enteric viruses and . In this review, we summarized current information on biosynthesis, transportation and metabolism of BAs and the role of BAs in replication of enteric caliciviruses, rotaviruses, and coronaviruses. We also discussed the application of BAs for cell culture adaptation of fastidious enteric caliciviruses and control of virus infection, which may provide novel insights into the development of antivirals and/or disinfectants for enteric viruses.
PubMed: 34778876
DOI: 10.1186/s44149-021-00003-x