Genetic Evolution of Hepatitis E Virus.

Comparative analysis of the genomic sequences of multiple hepatitis E virus (HEV) isolates has revealed extensive genomic diversity among them. Recently, a variety of genetically distinct HEV variants have also been isolated and identified from large numbers of animal species, including birds, rabbits, rats, ferrets, bats, cutthroat trout, and camels, among others. Furthermore, it has been reported that recombination in HEV genomes takes place in animals and in human patients. Also, chronic HEV infection in immunocompromised individuals has revealed the presence of viral strains carrying insertions from human genes. This paper reviews current knowledge on the genomic variability and evolution of HEV.

Hepatitis E virus infection and its associated adverse feto-maternal outcomes among pregnant women in Qinhuangdao, China.

Background and aims: The aim of this study was to investigate the positive rate of hepatitis E virus (HEV) infection and the possible adverse outcomes in pregnant women of Qinhuangdao, China.Methods: Serum samples of 946 pregnant women were collected from July 2017 to October 2017 in Qinhuangdao First Hospital. All samples were tested for anti-HEV IgM and IgG antibodies by enzyme-linked immunosorbent assay (ELISA). HEV RNA was tested by reverse transcription-nested polymerase chain reaction (RT-nPCR) and the PCR products were sequenced.Results: Of the 946 samples, the positive rate of anti-HEV IgM (15/365, 4.11%), anti-HEV IgG (74/365, 20.27%) and both anti-HEV IgM and IgG (12/365, 3.29%) were significantly higher (p < .05) in third trimester pregnant women than in the first (3/288, 1.04%; 36/288, 12.5%; 4/288, 1.39%), and second trimesters (6/293, 2.05%; 29/293, 9.90%; 2/293, 0.68%). The average alanine transaminase (ALT) level (34.49 ± 10.15) and the incidence of adverse pregnancy outcomes (13/18, 72.22%) in the both anti-HEV IgM and IgG positive group were significantly higher than other groups (p < .05). HEV RNA was detected in 1/181 (0.55%) of pregnant women with a history of HEV infection and the detected HEV strain belonged to subgenotype 4a.Conclusions: This study showed that pregnant women who have HEV infection can possibly lead to adverse pregnancy outcomes.

Transmission of a Novel Genotype of Hepatitis E Virus from Bactrian Camels to Cynomolgus Macaques.

Hepatitis E virus (HEV) is zoonotic and a major cause of acute viral hepatitis worldwide. Recently, we identified a novel HEV genotype 8 (HEV8) in Bactrian camels in Xinjiang, China. However, the epidemiology, pathogenicity, and zoonotic potential of HEV8 are unclear. Here, we present the prevalence of HEV8 in China and investigate its pathogenicity and cross-species transmission in cynomolgus macaques. Fresh fecal and milk samples from Bactrian camels collected from four provinces/regions in China were screened for HEV RNA by reverse transcriptase PCR (RT-PCR). An HEV8-positive sample was used to inoculate two cynomolgus macaques to examine the potential for cross-species infection. The pathogenicity of HEV8 was analyzed by testing HEV markers and liver function during the study period and histopathology of liver biopsy specimens at 3, 13, and 25 weeks postinoculation. Extrahepatic replication was tested by using reverse transcriptase quantitative PCR (RT-qPCR) and immunofluorescence assays. The overall prevalence of HEV8 RNA in Chinese Bactrian camels was 1.4% (4/295), and positive samples were found in three different provinces/regions in China. Histopathology confirmed acute and chronic HEV8 infections in the two monkeys. Multiple tissues were positive for HEV RNA and ORF2 proteins. Renal pathology was observed in the monkey with chronic hepatitis. Whole-genome sequencing showed only 1 to 3 mutations in the HEV8 in the fecal samples from the two monkeys compared to that from the camel. HEV8 is circulating in multiple regions in China. Infection of two monkeys with HEV8 induced chronic and systemic infections, demonstrating the high potential zoonotic risk of HEV8.IMPORTANCE It is estimated that one-third of the world population have been exposed to hepatitis E virus (HEV). In developed countries and China, zoonotic HEV strains are responsible for almost all acute and chronic HEV infection cases. It is always of immediate interest to investigate the zoonotic potential of novel HEV strains. In 2016, we discovered a novel HEV genotype, HEV8, in Bactrian camels, but the epidemiology, zoonotic potential, and pathogenicity of the virus were unknown. In the present study, we demonstrated that HEV8 was circulating in multiple regions in China and was capable of infecting cynomolgus macaques, a surrogate for humans, posing high risk of zoonosis. Chronic hepatitis, systemic infection, and renal pathology were observed. Collectively, these data indicate that HEV8 exhibits a high potential for zoonotic transmission. Considering the importance of Bactrian camels as livestock animals, risk groups, such as camelid meat and milk consumers, should be screened for HEV8 infection.

Evaluation of antiviral efficacy of Chinese traditional medicine Babao Dan in rabbits infected with hepatitis E virus.

Hepatitis E virus (HEV) is a major cause of acute viral hepatitis. Patients with chronic hepatitis B superinfected with HEV may progress to liver failure. Babao Dan (BD) is a traditional Chinese medicine widely used as an auxiliary option for the treatment of chronic hepatitis and liver cancer in China. This study aimed to evaluate the effect of BD on the management of HEV infection in a rabbit model. Sixty-two specific-pathogen-free (SPF) rabbits were divided randomly into five groups and treated with BD or placebo for 2 weeks. All rabbits were inoculated intravenously with rabbit HEV after initial administration. Then, rabbits were administered BD or ribavirin or placebo at 2 weeks post-inoculation (wpi) until faecal virus shedding showed negative. The duration of faecal virus shedding and levels of HEV RNA in faeces were reduced, and anti-HEV antibodies were detected in all rabbits in groups treated with BD before or after inoculation. Ribavirin treatment rapidly cleared HEV infection in SPF rabbits, but anti-HEV antibodies remained negative in 50 % of rabbits treated with ribavirin. These results indicate that ribavirin treatment was more effective in clearing HEV infection, while administration of BD before or after inoculation was effective in clearing HEV infection. Further clinical studies are warranted.

Different susceptibility and pathogenesis of rabbit genotype 3 hepatitis E virus (HEV-3) and human HEV-3 (JRC-HE3) in SPF rabbits.

Hepatitis E virus (HEV) is an increasingly important zoonotic infection in humans with HEV genotypes 3 and 4 being recognized as zoonotic pathogens. The relatively recently isolated genotype 3 rabbit HEV (rHEV-3) and the more well known genotype 3 isolates from humans and swine (hsHEV-3) have all been confirmed experimentally to be capable of infecting both non-human primates and specific-pathogen free (SPF) pigs. In a previous study rHEV-3 was shown to cause acute hepatitis in experimentally infected rabbits. However, whether hsHEV-3 can productively infect rabbits remained unclear. The objective of this study was to investigate the experimental infection of rabbits with human HEV-3 (hHEV-3, JRC-HE3), to compare it to that with rHEV-3 (CHN-BJ-rb14) and to further characterise the pathogenesis of the two isolates. All animals inoculated with rHEV-3 (CHN-BJ-rb14) became infected, exhibiting an intermittent viremia, elevated liver enzymes, and persistent fecal virus shedding throughout the 15 week study period. Liver histopathology showed acute inflammation and both positive- and negative-stranded viral RNA was detected in various tissues from necropsied rabbits. By contrast, neither sero-conversion nor alanine aminotransferase (ALT) elevation was observed in most rabbits inoculated with hHEV-3 (JRC-HE3). In addition, rHEV-3 (CHN-BJ-rb14) but not hHEV-3 (JRC-HE3) recovered from primary infected rabbits was transmissible to naive rabbits. These results showed that SPF rabbits are readily susceptible to infection with rHEV-3 (CHN-BJ-rb14) but not hHEV-3 (JRC-HE3), which might indicate the influence of viral genomic organization on its pathogenicity.

Development and validation of a new serum standard for the measurement of anti-HEV antibodies in animals.

Although hepatitis E virus (HEV) infection is a zoonosis, there is, currently, no standardized assay for quantitatively measuring anti-HEV antibody levels in HEV animal reservoirs. In this study, anti-HEV antibody positive serum from a rabbit (RS26) was calibrated by dose-response parallel line assay using the World Health Organization (WHO) reference standard for anti-HEV antibodies. After evaluating the stability of the RS26 serum, a quantification assay of anti-HEV antibodies using RS26 as a standard was developed and evaluated for both reproducibility and suitability to field studies. The anti-HEV antibody level of RS26 was calculated to be 39.54 IU/ml. A series of standard working serum for anti-HEV antibodies consisted of five serum dilutions (3.950 IU/ml, 1.975 IU/ml, 0.986 IU/ml, 0.494 IU/ml, and 0.247 IU/ml). The quantitative assay using RS26 showed good range and reproducibility, effectively measuring the dynamics of anti-HEV antibody concentrations in pigs and rabbits. In conclusion, we have developed a a stable and reproducible serum standard for the quantitation of anti-HEV antibodies. J. Med. Virol. 89:497-501, 2017. © 2016 Wiley Periodicals, Inc.

Genetic Evolution of Hepatitis E Virus.

Comparative analysis of the genomic sequences of multiple hepatitis E virus (HEV) isolates has revealed extensive genomic diversity among them. Recently, a variety of genetically distinct HEV variants have also been isolated and identified from large numbers of animal species, including birds, rabbits, rats, ferrets, bats, cutthroat trout, and camels, among others. Furthermore, it has been reported that recombination in HEV genomes takes place in animals and in human patients. Also, chronic HEV infection in immunocompromised individuals has revealed the presence of viral strains carrying insertions from human genes. This paper reviews the current knowledge on the genomic variability and evolution of HEV.

Hepatitis E Virus in 3 Types of Laboratory Animals, China, 2012-2015.

We found seroprevalences for hepatitis E virus (HEV) of 7.5%, 18.5%, and 83.3% in specific pathogen-free (SPF) laboratory rabbits, monkeys, and pigs, respectively, in China. HEV RNA was detected in 4.8% of SPF rabbits, and 11 rabbits had latent infections. Screening for HEV in SPF animals before relevant experiments are conducted is recommended.

Drosophila Dicer-2 has an RNA interference-independent function that modulates Toll immune signaling.

Dicer-2 is the central player for small interfering RNA biogenesis in the Drosophila RNA interference (RNAi) pathway. Intriguingly, we found that Dicer-2 has an unconventional RNAi-independent function that positively modulates Toll immune signaling, which defends against Gram-positive bacteria, fungi, and some viruses, in both cells and adult flies. The loss of Dicer-2 expression makes fruit flies more susceptible to fungal infection. We further revealed that Dicer-2 posttranscriptionally modulates Toll signaling because Dicer-2 is required for the proper expression of Toll protein but not for Toll protein stability or Toll mRNA transcription. Moreover, Dicer-2 directly binds to the 3' untranslated region (3'UTR) of Toll mRNA via its PAZ (Piwi/Argonaute/Zwille) domain and is required for protein translation mediated by Toll 3'UTR. The loss of Toll 3'UTR binding activity makes Dicer-2 incapable of promoting Toll signaling. These data indicate that the interaction between Dicer-2 and Toll mRNA plays a pivotal role in Toll immune signaling. In addition, we found that Dicer-2 is also required for the Toll signaling induced by two different RNA viruses in Drosophila cells. Consequently, our findings uncover a novel RNAi-independent function of Dicer-2 in the posttranscriptional regulation of Toll protein expression and signaling, indicate an unexpected intersection of the RNAi pathway and the Toll pathway, and provide new insights into Toll immune signaling, Drosophila Dicer-2, and probably Dicer and Dicer-related proteins in other organisms.

Efficient Catalytic Activity BiFeO3 Nanoparticles Prepared by Novel Microwave-Assisted Synthesis.

A novel microwave-assisted sol-gel method was applied to the synthesis of the single-phase perovskite bismuth ferrite nanoparticles (BFO NPs) with the mean diameter ca. 73.7 nm. The morphology was characterized by scanning electron microscope (SEM). The X-ray diffraction (XRD) revealed the rhombohedral phase with R3c space group. The weak ferromagnetic behavior at room temperature was affirmed by the vibrating sample magnetometer (VSM). According to the UV-vis diffuse reflectance spectrum (UV-DSR), the band gap energy of BFO NPs was determined to be 2.18 eV. The electrochemical activity was evaluated by BFO NPs-chitosan-glassy carbon electrode (BFO-CS-GCE) sensor for detection of p-nitrophenol contaminants. The material showed an efficient oxidation catalytic activity by degrading methylene blue (MB). It was found that the degradation efficiency of 10 mg L-1 MB at pH 6.0 was above 90.9% after ultrasound- and microwave-combined-assisted (US-MW) irradiation for 15 min with BFO NPs as catalyst and H202 as oxidant. A possible reaction mechanism of degradation of MB was also proposed.