Herpes Simplex Virus Encephalitis Complicated by Acute Ischemic Stroke

Introduction: Herpes simplex virus is the most common etiology for life-threatening sporadic encephalitis worldwide. Antiviral therapy with acyclovir has been shown to reduce mortality and should be started promptly in patients with clinically suspected viral encephalitis before serological confirmation of the diagnosis. Despite antiviral treatment, it is associated with significant mortality and a wide range of neurologic sequelae or neuropsychiatric disorders. Clinical presentation includes fever, headache, altered mental status, and focal or generalized seizures. In some cases, it can present with focal neurological deficits, such as an acute stroke. The aim of this study is to identify rare complications of HSVE. Presentation: We present a case of a 71-year-old female patient with herpes virus encephalitis and an ischemic cerebral accident. The findings of CT scan of the brain revealed an extensive right temporal hypodensity. CSF findings include an elevated protein level, normal glucose level and pleocytosis with lymphocyte predominance. The lumbar tap confirmed the presence of herpes simplex virus type 1 with polymerase chain reaction (PCR) in the CSF. Neurological manifestations include focal neurological deficit with left-sided hemiparesis and coma. After 40 days of complex therapy, an improvement in the mental state was observed. Conclusion: There are varying degrees of neurologic sequelae among survivors in children and adults despite the antiviral treatment. Herpes simplex encephalitis has significant morbidity and high mortality due to the lack of prophylactic treatment and preventable strategies.

Varicella-Zoster Virus Encephalitis with Hyponatremia in an Immunocompetent Elderly Patient:A Case Report

As a common cause of viral encephalitis,varicella-zoster virus(VZV)may invade the central nervous system of immunosuppressed patients during reactivation.Herein,we report a rare case of an immunocompetent patient with VZV encephalitis who developed severe hyponatremia and was considered to have a suspected primary infection.The patient was diagnosed with the support of second-generation sequencing and had persistent hyponatremia after being cured.Although rare,this case suggests that VZV encephalitis may occur in unexpected patients and present with unusual clinical manifestations,requiring advanced detection methods and clinical expertise for resolution.

Isolated Hyperacute T-Waves in West Nile Encephalitis Indicating Atypical Variant of Stress-Induced Cardiomyopathy

Several cardiac outcomes have been reported with West Nile-encephalitis;however, the underlying pathophysiology remains complex. We present a 42-year-old female, with multiple sclerosis, whose neurological symptoms and respiratory decline were finally explained by the diagnosis of West Nile-encephalitis. During her admission, the isolated peaked T-waves indicated the underlying stress-induced cardiomyopathy. The absence of all other causes of hyperacute T-waves, their subsequent resolution with the resolution of infection and improvement in wall motion abnormalities, further supported the association. This case highlights the importance of considering hyperacute T-waves in an approach towards the diagnosis of WNV-encephalitis related atypical variant of stress-induced cardiomyopathy.

Serological Investigation into the Infected Genotypes of Patients with Japanese Encephalitis in the Coastal Provinces of China

Objective Genotypes(G)1,3,and 5 of the Japanese encephalitis virus(JEV)have been isolated in China,but the dominant genotype circulating in Chinese coastal areas remains unknown.We searched for G5 JEV-infected cases and attempted to elucidate which JEV genotype was most closely related to human Japanese encephalitis(JE)in the coastal provinces of China.Methods In this study,we collected serum specimens from patients with JE in three coastal provinces of China(Guangdong,Zhejiang,and Shandong)from 2018 to 2020 and conducted JEV cross-neutralization tests against G1,G3,and G5.Results Acute serum specimens from clinically reported JE cases were obtained for laboratory confirmation from hospitals in Shandong(92 patients),Zhejiang(192 patients),and Guangdong(77 patients),China,from 2018 to 2020.Seventy of the 361 serum specimens were laboratory-confirmed to be infected with JEV.Two cases were confirmed to be infected with G1 JEV,32 with G3 JEV,and two with G5 JEV.Conclusion G3 was the primary infection genotype among JE cases with a definite infection genotype,and the infection caused by G5 JEV was confirmed serologically in China.

Autoimmune complications and clinical outcomes of herpes simplex encephalitis in children: A case series

Objective:To report the neurologic prognosis and autoimmune complications of 16 cases of childhood herpes simplex virus encephalitis.Methods:The study was conducted atŞanlıurfa Training and Research Hospital,Turkey from June 2017 to August 2019.The study included 16 pediatric patients aged between 6 months and 17 years(median age 77.7 months)who were diagnosed with herpes simplex virus type 1 encephalitis by pediatric infectious disease and pediatric neurology clinics.Patients were followed using patient records,and interviews at the pediatric neurology clinic or via the telephone.Clinical and demographic data,received therapies,neurologic prognosis and complications were evaluated.Results:Patients with and without autoimmune encephalitis were compared in terms of age,sex,symptom duration before treatment,initial cerebrospinal fluid protein,glucose,red blood count and white blood count but no significant difference was found.Autoimmune complications were seen in four patients.N-methyl-D-aspartate encephalitis was observed in three patients and choreoathetosis was seen in one patient.The average follow-up period was 48.3 months.Twenty-five percent of the patients were receiving multiple antiepileptic drug(AED)treatment,43.8%were receiving single AED treatment and 31.3%were not receiving AED treatment at the end of the follow-up.Motor disability was observed in 12.5%and drug-resistant epilepsy was observed in 6.3%who had autoimmune complications.Conclusions:Seizures and movement disorders were controlled with immunotherapy and autoantibodies should be studied routinely.Treatment should be started early upon recognition of autoimmune complications through follow-up by measuring autoantibody levels and clinical examination results.Effective prevention and curative treatment modalities are needed to avoid herpes simplex virus encephalitis complications.

TaqMan Real-time RT-PCR Assay for Detecting and Differentiating Japanese Encephalitis Virus

Objective To detect Japanese encephalitis virus（JEV） rapidly and distinguish its genotypes, a TaqMan-based reverse transcriptase quantitative polymerase chain reaction（RT-PCR） detection system was developed.Methods By aligning the full-length sequences of JEV（G1-G5）, six sets of highly specific TaqMan real-time RT-PCR primers and probes were designed based on the highly conserved NS1, NS2, and M genes of JEV, which included one set for non-specific JEV detection and five sets for the detection of specific JEV genotypes. Twenty batches of mosquito samples were used to evaluate our quantitative PCR assay.Results With the specific assay, no other flavivirus were detected. The lower limits of detection of the system were 1 pfu/mL for JEV titers and 100 RNA copies/μL. The coefficients of variation of this real-time RT-PCR were all 〈 2.8%. The amplification efficiency of this method was between 90% and 103%.Conclusion A TaqMan real-time RT-PCR detection system was successfully established to detect and differentiate all five JEV genotypes.

Molecular Characterization of Full-length Genome of Japanese Encephalitis Virus Genotype V Isolated from Tibet, China

Objective To determine the molecular characterization of full-length genome of Japanese encephalitis virus （JEV） genotype V. Methods The full-length nucleotide sequences of JEV strains isolated from different locations and sources were used in sequence and phylogenetic analysis. Results The full-length genome of genotypes V JEV, XZ0934, and Muar strain were composed of 10 983 and 10 988 nucleotides respectively and shared a lower level of identity with JEV genotypes I-IV, ranging from 78.4% （G I, KV1899） to 79.7% （G III, JaGAr01）, for the nucleotide sequences, and from 90.0%（G I, KV1899） to 91.8%（G III, JaGAr01） for the amino acid sequences. The open reading frame （ORF） of JEV genotype V spanned nucleotides 96 to 10 397 and encoded 3 433 amino acids. Interestingly, a comparison with JEV genotype I-IV revealed that 3 nucleotides （encoded with a serine residue） were inserted in the NS4A gene of JEV genotype V, and the insertion of nucleotides was also found in downstream of the ORF stop codon in 3’-untranslated region. Moreover, numerous amino acid mutations were observed in 3 functional domains of the E gene of JEV genotype V. Conclusion The molecular characterization of JEV genotype V is significantly different from that of the known genotypes I-IV. The mutations located in the coding region and the non-coding region may be molecular markers of JEV genotype V and warrant further studies to determine their effects on biology and immunogenicity of genotype V strains.

Use of a Multiplex RT-PCR Assay for Simultaneous Detection of the North American Genotype Porcine Reproductive and Respiratory Syndrome Virus,Swine Influenza Virus and Japanese Encephalitis Virus

A multiplex reverse transcriptase-polymerase chain reaction(multiplex RT-PCR) assay was developed and subsequently evaluated for its efficacy in the detection of multiple viral infections simultaneously,in swine.Specific primers for each of the 3 RNA viruses,North American genotype porcine reproductive and respiratory syndrome virus,Japanese encephalitis virus,and swine influenza virus,were used in the testing procedure.The assay was shown to be highly sensitive because it could detect as little as 10-5 ng of each of the respective amplicons in a single sample containing a composite of all 3 viruses.The assay was also effective in detecting one or more of the same viruses in various combinations in specimens,including lymph nodes,lungs,spleens,and tonsils,collected from clinically ill pigs and in spleen specimens collected from aborted pig fetuses.The results from the multiplex RT-PCR were confirmed by virus isolation.The relative efficiency(compared to the efficiency of separate assays for each virus) and apparent sensitivity of the multiplex RT-PCR method show that this method has potential for application in routine molecular diagnostic procedures.

Inhibition of Japanese Encephalitis Virus Infection by Flavivirus Recombinant E Protein Domain Ⅲ

Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus closely related to the human pathogens including yellow fever virus, dengue virus and West Nile virus. There are currently no effective antiviral therapies for all of the flavivirus and only a few highly effective vaccines are licensed for human use. In this paper, the E protein domain III (DIII) of six heterologous flaviviruses (DENV1-4, WNV and JEV) was expressed in Escherichia coli successfully. The proteins were purified after a solubilization and refolding procedure, characterized by SDS-PAGE and Western blotting. Competitive inhibition showed that all recombinant flavivirus DIII proteins blocked the entry of JEV into BHK-21 cells. Further studies indicated that antibodies induced by the soluble recombinant flavivirus DIII partially protected mice against lethal JEV challenge. These results demonstrated that recombinant flavivirus DIII proteins could inhibit JEV infection competitively, and immunization with proper folding flavivirus DIII induced cross-protection against JEV infection in mice, implying a possible role of DIII for the cross-protection among flavivirus as well as its use in antigens for immunization in animal models.

Surface Display of Domain Ⅲ of Japanese Encephalitis Virus E Protein on Salmonella Typhimurium by Using an Ice Nucleation Protein

A bacterial cell surface display technique based on an ice nucleation protein has been employed for the development of live vaccine against viral infection. Due to its ubiquitous ability to invade host cells, Salmonella typhimurium might be a good candidate for displaying viral antigens. We demonstrated the surface display of domain III of Japanese encephalitis virus E protein and the enhanced green fluorescent protein on S. typhimurium BRD509 using the ice nucleation protein. The effects of the motif in the ice nucleation protein on the effective display of integral protein were also investigated. The results showed that display motifs in the protein can target integral foreign protein on the surface of S. typhimurium BRD509. Moreover, recombinant strains with surface displayed viral proteins retained their invasiveness, suggesting that the recombinant S. typhimurium can be used as live vaccine vector for eliciting complete immunogenicity. The data may yield better understanding of the mechanism by which ice nucleation protein displays foreign proteins in the Salmonella strain.

Development of an Indirect ELISA Using Recombinant Truncated Envelope Glycoprotein for Detection of Antibodies against Japanese Encephalitis Virus

[ Objective] To develop an indirect ELISA assay for detecting antibodies against envelope glycoprotein （ E protein） of Japanese encephalitis virus （JEV）. [ Method] Specific primers were designed according to JEV sequences published in the GenBank. The cDNA of JEV E gene （about 1 000 10p） was amplified by the RT-PCR with the specific primers. After sequencing analysis, the E gene was cloned into pET30a expression vector and expressed in E. coli BL21 （DE3） with the induction of IPTG. After denaturation, purification and renaturation, the recombinant protein was analyzed by the SDS-PAGE and the westem blotting. An indirect ELISA was developed to detect antibodies against JEV. [ Result] The E protein was mainly expressed in inclusion body. With the purified E protein, the indirect ELISA was developed and displayed good specificity, sensitivity and repeatability, [ Conclusion]The developed ELISA using the truncated E protein as antigen is a simple, convenient and rapid serological method for diagnosis, monitoring antibody level and epidemiological investigation of JEV.

Preparation of Polyclonal Antibodies against NS3 Protein of Japanese Encephalitis Virus

Japanese encephalitis （JE） is a central nervous system disease caused by Japanese encephalitis virus （JEV）, which can infect human and a variety of animals and cause irreversible nerve damages. NS3 protein plays an important role in the process of JEV polyprotein hydrolysis, which is essential for JEV replication. Therefore, NS3 protein may be used as a potential drug target to treat Japanese encephalitis. In this study, the pET-28a-NS3 plasmid was successfully constructed and expressed in E. coli BL21 （ DE3 ） under IPTG induction. The molecular weight of the expressed recombinant protein was 55 ku, which was consistent with the expected result. The positive serum was prepared by immunizing BALB/c mice with NS3 protein and identified by indirect immunofluorescence （IFA）. The results showed that there was a fluorescence reaction between the prepared positive serum of NS3 protein and cells infected with JEV.

Study on DNA Immunization by Recombinants Encoding Japanese Encephalitis Virus prME and E Proteins

To study the expression characteristic of Japanese encephalitis virus (JEV) prME and E proteins and the efficacy of DNA immunization by different recombinant plasmids containing JEV prME (2001 bp) and E (1500 bp) genes, two recombinants (pJME and pJE) containing JEV prME and E genes fused with FLAG were constructed and then transfected into HepG2 and COS-1 cells by liposome fusion. The expression feature of FLAG-prME (about 72 kDa) and FLAG-E (about 54 kDa) proteins in transfected cells were analyzed by Western blot and two antibody systems (anti-FLAG and anti-E). BALB/c mice were immunized with 100 μg of two kinds of recombinants by intramuscular injection, and JEV JaGAr-01 strains (10 5 PFU/100 μl)were given to BALB/c mice by intraperioneal injection 3 wk after twice DNA immunization by a lethal virus challenge. BALB/c mice were observed for 21 days after challenge. 80% plaque reduction neutralization test was performed to titrate neutralization antibody before and after viral challenge. It was found that the expression of proteins associated with pJME and pJE was determined in transfected cells with anti-FLAG and a new protein of 11 kDa was detected in HepG2 and COS-1 cells transfected with pJME. Only E (53 kDa) protein was identified as transfected with pJME using anti-E. Higher level of neutralization antibodies and the efficacy of protective immunity were induced with pJME immunization, and were similar to those induced by inactivated Japanese encephalitis vaccine, but were better than those induced with pJE. It concludes that the expression level from prM to E proteins of JEV is different in vitro, and the in vitro expression efficiency of pJME was better than that of pJE. FLAG-prME protein expressed by pJME could be cleaved by peptidase from host. The efficacy of DNA immunization is correlated to the expression characterization of related proteins expressed in vitro.

Prevalence and risk factors associated with Japanese encephalitis virus infection in swine population of Assam,India

Objective:To assess the prevalence of Japanese encephalitis virus(JEV)and associated risk factors in the swine population of Assam.Methods:A total of 432 swine serum and blood samples were collected from Barpeta and Sonitpur districts of Assam and were screened for the presence of JEV antibodies.Information related to risk factors was collected using a self-designed questionnaire from 120 swine-rearing farmers.Linear-mixed models were used for prevalence estimation.Univariate and multivariate regression models were constructed to evaluate the association of demography,season and management practices with JEV positive status.Results:Overall,the JEV infection prevalence was 51.6%at farm and 47.1%at slaughter premises.Phylogenetic analysis of partial sequence of envelope gene of two positive field samples revealed that both isolates belonged to genotypeⅢJEV.Isolate 1 shared a common clade with human isolates while isolate 2 belonged to the same clade as that of other JEV swine strain isolated from India.The final multivariate model showed that two factors including monsoon season(Adjusted OR 5.6;95%CI 2.1-14.9;P<0.001)and water logging in the area near the pig shelter(Adjusted OR 16.9;95%CI 6.1-47.3;P<0.001)were associated with greater odds of swine being infected with JEV.Conclusions:High prevalence of JEV in swine population of Assam state indicates a significant risk of virus transmission to humans while risk factor study underlines the urgent need for awareness campaigns in the Assam.

E Sequence Analysis of Persistently Infected Mutant Japanese Encephalitis Virus Strains

Summary： A persistent infection model was established after human hepatoma cells infected by Japanese encephalitis viruses were subcultured for several times. Viral titers of mutant viruses in persistently infected cells were examined by plaque methods using BHK cells. Nucleotides of the E coding region of two wild and two mutant viruses were amplified by RT-PCR. PCR products were sequenced by ABI-PRSM^TM310 sequencing system. Compared to JaGAr-01 wild strains, four amino acids were replaced （E61Tyr→Asp, E219His→Tyr, E384Val→Glu, E418Pro→Ala） in the E sequence of JaGAr-01 persistently-infected mutant strains. Eleven amino acid replacement （E51Arg →Ser, E61Tyr→Asp, E83Lys→Glu, E123Ser→Arg, E209Arg→Lys, E227Pro→Ser, E276Asp→er, E290Arg→Lys, E387Lys→Arg, E418Leu→Pro, E454Arg→Gly） was also noted when we compared the E sequence between persistently infected Nakayama and its wild strains. A lot of similarities of amino acid sequence between mutant strains JaGAr-01 and Nakayama were also noted. It was concluded that geno-variation existed in E region of mutant viruses and the mutant protein encoded by E region, especially the mutation of E61 （Tyr→Asp） may contribute to the maintenance of the persistent infection of Japanese encephalitis virus.

Suramin Inhibits the In Vitro Expression of Encephalitis B Virus Proteins NS3 and E

In this study, the mechanism by which Suramin inhibits the replication of epidemic encephalitis B virus was explored to provide a theoretical basis for its further application in clinical practice. After viral infection of HepG2 and IMR 32 cells, different concentrations of Suramin were added to the culture media, and then the cultural supernatants and infected cells were collected 48 h later. For the evaluation of the curative effect, cytopathic effect (CPE), virus titers, the expression of viral protein and viral RNA were determined by Western blot, RT PCR and in vitro RNA synthesis, respectively. At the concentration of 50 μg/ml of Suramin, HepG2 and IMR 32 infected with epidemic encephalitis B virus decreased by 51.8 % and 0.03 % respectively, as compared with controls. It was suggested that expression of encephalitis B virus proteins NS3 and E was notably reduced by Suramin. This is especially true of E protein. At RNA level, however, no difference in RNA virus was found between Suramin treated virus and non treated cells. Our results suggest that Suramin can inhibit viral replication by blocking the production of viral proteins.

Phylogeny and Homologous Recombination in Japanese Encephalitis Viruses

Japanese encephalitis virus（JEV） is a significant causative agent of arthropod-borne encephalitis and what is less clear that the factors cause the virus wide spread. The objective was to confirm whether the homologous recombination imposed on JEV. The phylogenetic and homologous recombination analyses were performed based on 163 complete JEV genomes which were recently isolated. They were still separated into five genotypes（GI-GV） and the most of recently isolated JEVs were GI rather than GIII in Asian areas including China's Mainland. Two recombinant events were identified in JEV and the evidence of the recombination was observed between China and Japan isolates that partitioned into two distinct subclades, but still the same genotype（GIII）. Our data further suggested that most of the nucleotides in JEV genome were under negative selection; however, changes within codon 2 316（amino acid NS4b-44） showed an evidence of the positive selection.

Construction and Preliminary Application of RT-LAMP Detection Method for Swine Japanese B Encephalitis Virus

[ Objective] This study aimed to establish a rapid, sensitive and specific method using reverse transcription loop-mediated isothermal amplification （RT-LAMP） technology to detect swine Japanese B encephalitis virus （JEV）. [ Method ] Four specific LAMP primers were designed according to six loci the conservative region of JEV E gene sequence. Positive JEV RNA sample was used as a template for one-step amplification, and the reaction conditions and reaction system were optimized. [ Result] Experimental results showed that the established method had high sensitivity, with the detection limit of 0.5pg; specificity experi- ments indicated that the method had high specificity and there was no amplification reaction for other viral pathogens. The coincidence rate between detection results of RT-LAMP and RT-Nested-PCR was 90.9%. After RT-LAMP reaction, a chemiluminescent agent was added for visual observation, which greatly reduced the detection time. This method required no special equipment but only a water bath, which was a simple, sensitive and rapid detection method for swine Japanese B encephalitis virus and could be applied in primary laboratories. [ Conclusion] An RT-LAMP detection method for swine Japanese B encephalitis virus was successfully established and preliminarily applied in clinical practice.

Cloning and Sequence Analysis of the Full-Length Genome of Japanese encephalitis virus Strain SXBJ07 Isolated from Swine

A virus strain, showing cytopathic effect in BHK-21 cell, was isolated from swine brains in Shaanxi Province, China, in 2007. The isolate was confirmed as Japanese encephalitis virus （JEV） by immunofluorescence assay （IFA） and reverse transcription polymerase chain reaction （RT-PCR）, and named SXBJ07. The complete nueleotide and deduced amino acid sequences of the JEV strain SXBJ07 were determined. Its single open reading frame has a total of 3 432 amino acid residues. An extensive E gene based phylogenetic analysis was performed, the result showed that SXBJ07 strain belongs to genotype I. Comparison of the SXBJ07 genomic sequence with those of the 24 fully sequenced JEV strains in published databases showed nucleotide homology ranging from 99.0 to 83.7%; amino acid homology ranged from 99.8 to 94.8%. Compared SXBJ07 with SA14-14-2 strain, the current live vaccine strain in China, the homology of amino acid in envelope gene was 97.0%; and there were amino acid substitutions in 13 sites of the active domains of E protein （E1-E411）.

Japanese Encephalitis Virus Replication and Inhibitory Effect of shRNA in Mice

Japanese Encephalitis Virus (JEV) is responsible for over 30,000 annual cases of encephalitis worldwide, causing 30% mortality. JEV is thus a continuing threat to public health, so development of new antiviral drugs against JEV is desirable. Here, we examined JEV replication in mouse and used a short hairpin RNA JRi as the antiviral agent. The features of virus replication in neuron and survival rates of mice infected with JEV were different between virus strains. The mice infected with the virulent JEV strain (JaGAr01) were injected with pJRi (100 μg/mouse) which produced shRNAJRi. The survival rates of mice treated at 3 days before, the same day and 3 days after JEV infection were 22%, 78% and 44%, respectively. In addition, we demonstrated that the injection of pJRi induced interferon (IFN) production in cells and mice. These results suggest that the replication of JEV can be efficiently inhibited by RNAi and innate immunity including IFN. These data mean that pJRi has the inhibitory activity against JEV infection in vivo, and could be used as an antiviral drug to treat JEV infection.