scholarly journals Phylogenetic analysis of two new complete genomes of the hepatitis E virus (HEV) genotype 3 from Thailand

2020 ◽  
Vol 47 (11) ◽  
pp. 8657-8668
Author(s):  
Tipsuda Chanmanee ◽  
Pravech Ajawatanawong ◽  
Suda Louisirirotchanakul ◽  
Watcharasak Chotiyaputta ◽  
Siwaporn Chainuvati ◽  
...  

AbstractHepatitis E virus (HEV) is a causative agent of acute viral hepatitis globally. Evolutionary phylogeny classifies the HEV into eight genotypes that correlate with the viral transmission. Only four genotypes have been proven to be responsible for transmission in humans. However, there has been no report on the genomics and genotyping of HEV in Thailand during the past ten years. Here, we identified the genotype distributions of the Thai isolates of HEV and we sequenced two HEV genomes. We screened for 18 Thai isolates of HEV from Siriraj Hospital in Bangkok, from 2014–2016. The HEV genomes were sequenced from the serum and feces of a patient. The results showed that all Thai isolates of HEV were identified as genotype 3 (HEV-3). The ORF2 and genome phylogenies suggested two subgenotypes, called 3.1 and 3.2. The Thai isolates of HEV were frequently found in the subgenotype 3.1. The genome sequences of the two Thai isolates of HEV from the serum and fecal samples of the same patient showed 91% nucleotide similarity with the HEV genotype 3. Comparisons between the HEV genome and the ORF2 phylogenies illustrated that the ORF2 tree can be used to identify HEV genotypes, but it has less phylogenetic power for the HEV evolution. The two new genome sequences of HEV-3 from Thailand could contribute valuable information to the HEV genome study. (226 words)

2018 ◽  
Vol 56 (5) ◽  
Author(s):  
Bo Wang ◽  
Dominik Harms ◽  
C. Patrick Papp ◽  
Sandra Niendorf ◽  
Sonja Jacobsen ◽  
...  

ABSTRACT Autochthonous hepatitis E virus genotype 3 (HEV-3) infections in industrialized countries are more frequent than previously assumed. HEV-3 is zoonotic and the causal pathogen of chronic hepatitis E. According to the latest classification of the family Hepeviridae , 10 designated HEV-3 subtypes (HEV-3a to HEV-3j) and 7 unassigned HEV-3 subtypes are proposed. In order to identify and characterize the HEV-3 variants in circulation, we developed a molecular approach combining a sensitive HEV-specific real-time reverse transcription-PCR (RT-PCR) targeting the overlapping region of HEV ORF2 and ORF3 (the ORF2/3 region) and two newly designed consensus nested RT-PCRs targeting the HEV ORF1 and ORF2 genes, respectively. Since complete genome sequences are required for new HEV-3 subtype assignment, we implemented a straightforward approach for full-length HEV-3 genome amplification. Twenty-nine human serum samples and six human feces samples from chronic hepatitis E patients were selected for evaluation of the system. Viral loads ranged from 1 × 10 4 to 1.9 × 10 10 copies/ml of serum and from 1.8 × 10 4 to 1 × 10 12 copies/g of feces. Sequence and phylogenetic analyses of partial ORF1 and ORF2 sequences showed that HEV strains had considerable genetic diversity and clustered into the HEV-3c (29/35), HEV-3e (2/35), HEV-3f (2/35), and unassigned HEV-3 (2/35) subtypes. Moreover, from these strains, three full-length HEV-3 genome sequences were generated and characterized. DE/15-0030 represents a typical HEV-3c strain (95.7% nucleotide identity to wbGER27), while DE/15-0031 and SW/16-0282 have <89.2% homology to known HEV-3 strains and are phylogenetically divergent, indicating novel HEV-3 subtypes. In summary, our approach will significantly facilitate the detection, quantification, and determination of HEV-3 strains and will thus help to improve molecular diagnostics and our knowledge of HEV diversity and evolution.


2021 ◽  
Vol 10 (22) ◽  
Author(s):  
Florencia Cancela ◽  
Yanina Panzera ◽  
Victoria Mainardi ◽  
Solange Gerona ◽  
Natalia Ramos ◽  
...  

Hepatitis E is a leading cause of acute viral hepatitis worldwide. We report the full-length genome sequence of an HEV-3 strain obtained from a chronically infected patient from Uruguay. This strain shared only 86% nucleotide sequence identity with the most closely related reference strain belonging to subtype 3m.


Viruses ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 564 ◽  
Author(s):  
Laura Corneillie ◽  
Dominic Banda ◽  
Philip Meuleman

Hepatitis E virus (HEV) is an underdiagnosed pathogen with approximately 20 million infections each year and currently the most common cause of acute viral hepatitis. HEV was long considered to be confined to developing countries but there is increasing evidence that it is also a medical problem in the Western world. HEV that infects humans belongs to the Orthohepevirus A species of the Hepeviridae family. Novel HEV-like viruses have been observed in a variety of animals and some have been shown to be able to cross the species barrier, causing infection in humans. Several cell culture models for HEV have been established in the past years, but their efficiency is usually relatively low. With the circulation of this virus and related viruses in a variety of species, several different animal models have been developed. In this review, we give an overview of these animal models, indicate their main characteristics, and highlight how they may contribute to our understanding of the basic aspects of the viral life cycle and cross-species infection, the study of pathogenesis, and the evaluation of novel preventative and therapeutic strategies.


2017 ◽  
Vol 5 (35) ◽  
Author(s):  
Jakub Kubacki ◽  
Cornel Fraefel ◽  
Marco Jermini ◽  
Petra Giannini ◽  
Gladys Martinetti ◽  
...  

ABSTRACT We present here the full-length genome sequences of two hepatitis E virus genotype 3 (HEV-3) isolates from a human stool sample from a patient with acute hepatitis and a raw sausage containing pig liver. Sequence analysis implies that Swiss HEV isolates may form a novel subgroup of HEV-3 viruses.


2021 ◽  
Vol 11 ◽  
Author(s):  
Florence Nicot ◽  
Chloé Dimeglio ◽  
Marion Migueres ◽  
Nicolas Jeanne ◽  
Justine Latour ◽  
...  

Hepatitis E virus (HEV) genotype 3 is the most common genotype linked to HEV infections in Europe and America. Three major clades (HEV-3.1, HEV-3.2, and HEV-3.3) have been identified but the overlaps between intra-subtype and inter-subtype p-distances make subtype classification inconsistent. Reference sequences have been proposed to facilitate communication between researchers and new putative subtypes have been identified recently. We have used the full or near full-length HEV-3 genome sequences available in the Genbank database (April 2020; n = 503) and distance analyses of clades HEV-3.1 and HEV-3.2 to determine a p-distance cut-off (0.093 nt substitutions/site) in order to define subtypes. This could help to harmonize HEV-3 genotyping, facilitate molecular epidemiology studies and investigations of the biological and clinical differences between HEV-3 subtypes.


Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 267
Author(s):  
Shaoli Lin ◽  
Yan-Jin Zhang

Hepatitis E virus (HEV) is one of the causative agents for liver inflammation across the world. HEV is a positive-sense single-stranded RNA virus. Human HEV strains mainly belong to four major genotypes in the genus Orthohepevirus A, family Hepeviridae. Among the four genotypes, genotype 1 and 2 are obligate human pathogens, and genotype 3 and 4 cause zoonotic infections. HEV infection with genotype 1 and 2 mainly presents as acute and self-limiting hepatitis in young adults. However, HEV infection of pregnant women with genotype 1 strains can be exacerbated to fulminant hepatitis, resulting in a high rate of case fatality. As pregnant women maintain the balance of maternal-fetal tolerance and effective immunity against invading pathogens, HEV infection with genotype 1 might dysregulate the balance and cause the adverse outcome. Furthermore, HEV infection with genotype 3 can be chronic in immunocompromised patients, with rapid progression, which has been a challenge since it was reported years ago. The virus has a complex interaction with the host cells in downregulating antiviral factors and recruiting elements to generate a conducive environment of replication. The virus-cell interactions at an early stage might determine the consequence of the infection. In this review, advances in HEV virology, viral life cycle, viral interference with the immune response, and the pathogenesis in pregnant women are discussed, and perspectives on these aspects are presented.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
M. Meester ◽  
T. J. Tobias ◽  
M. Bouwknegt ◽  
N. E. Kusters ◽  
J. A. Stegeman ◽  
...  

Abstract Background Hepatitis E virus (HEV) genotype 3 and 4 is a zoonosis that causes hepatitis in humans. Humans can become infected by consumption of pork or contact with pigs. Pigs are the main reservoir of the virus worldwide and the virus is present on most pig farms. Main body Though HEV is present on most farms, the proportion of infected pigs at slaughter and thus the level of exposure to consumers differs between farms and countries. Understanding the cause of that difference is necessary to install effective measures to lower HEV in pigs at slaughter. Here, HEV studies are reviewed that include infection dynamics of HEV in pigs and on farms, risk factors for HEV farm prevalence, and that describe mechanisms and sources that could generate persistence on farms. Most pigs become infected after maternal immunity has waned, at the end of the nursing or beginning of the fattening phase. Risk factors increasing the likelihood of a high farm prevalence or proportion of actively infected slaughter pigs comprise of factors such as farm demographics, internal and external biosecurity and immunomodulating coinfections. On-farm persistence of HEV is plausible, because of a high transmission rate and a constant influx of susceptible pigs. Environmental sources of HEV that enhance persistence are contaminated manure storages, water and fomites. Conclusion As HEV is persistently present on most pig farms, current risk mitigation should focus on lowering transmission within farms, especially between farm compartments. Yet, one should be aware of the paradox of increasing the proportion of actively infected pigs at slaughter by reducing transmission insufficiently. Vaccination of pigs may aid HEV control in the future.


Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 277
Author(s):  
Eleonora Chelli ◽  
Elisabetta Suffredini ◽  
Paola De Santis ◽  
Dario De Medici ◽  
Santina Di Bella ◽  
...  

In Europe, foodborne transmission has been clearly associated to sporadic cases and small clusters of hepatitis E in humans linked to the consumption of contaminated pig liver sausages, raw venison, or undercooked wild boar meat. In Europe, zoonotic HEV-genotype 3 strains are widespread in pig farms but little information is available on the prevalence of HEV positive pigs at slaughterhouse. In the present study, the prevalence of HEV-RNA positive pigs was assessed on 585 animals from 4 abattoirs located across Italy. Twenty-one pigs (3.6%) tested positive for HEV in either feces or liver by real-time RT-PCR. In these 21 pigs, eight diaphragm muscles resulted positive for HEV-RNA. Among animals collected in one abattoir, 4 out of 91 plasma tested positive for HEV-RNA. ELISA tests for the detection of total antibodies against HEV showed a high seroprevalence (76.8%), confirming the frequent exposure of pigs to the virus. The phylogenetic analyses conducted on sequences of both ORF1 and ORF2 fragments, shows the circulation of HEV-3c and of a novel unclassified subtype. This study provides information on HEV occurrence in pigs at the slaughterhouse, confirming that muscles are rarely contaminated by HEV-RNA compared to liver, which is the most frequently positive for HEV.


Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 699
Author(s):  
Anna Mrzljak ◽  
Lorena Jemersic ◽  
Vladimir Savic ◽  
Ivan Balen ◽  
Maja Ilic ◽  
...  

Hepatitis E virus (HEV) is the most common cause of viral hepatitis globally. The first human case of autochthonous HEV infection in Croatia was reported in 2012, with the undefined zoonotic transmission of HEV genotype 3. This narrative review comprehensively addresses the current knowledge on the HEV epidemiology in humans and animals in Croatia. Published studies showed the presence of HEV antibodies in different population groups, such as chronic patients, healthcare professionals, voluntary blood donors and professionally exposed and pregnant women. The highest seroprevalence in humans was found in patients on hemodialysis in a study conducted in 2018 (27.9%). Apart from humans, different studies have confirmed the infection in pigs, wild boars and a mouse, indicating the interspecies transmission of HEV due to direct or indirect contact or as a foodborne infection. Continued periodical surveys in humans and animals are needed to identify the possible changes in the epidemiology of HEV infections.


2013 ◽  
Vol 19 (4) ◽  
pp. 686-688 ◽  
Author(s):  
Vanessa Salete de Paula ◽  
Matthias Wiele ◽  
Afegenwi H. Mbunkah ◽  
Achukwi M. Daniel ◽  
Manchang T. Kingsley ◽  
...  

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