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Lee AR, Kim SH, Hong SY, Lee SH, Oh JS, Lee KY, Kim SJ, Ishikawa T, Shim SM, Lee HI, Seo SU. Characterization of genotype V Japanese encephalitis virus isolates from Republic of Korea. Emerg Microbes Infect 2024; 13:2362392. [PMID: 38808613 PMCID: PMC11168223 DOI: 10.1080/22221751.2024.2362392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 05/27/2024] [Indexed: 05/30/2024]
Abstract
Japanese encephalitis (JE), caused by the Japanese encephalitis virus (JEV) infection, continues to pose significant public health challenges worldwide despite efficient vaccines. The virus is classified into five genotypes, among which genotype V (GV) was not detected for a long period after its initial isolation in 1952, until reports emerged from China and the Republic of Korea (ROK) since 2009. The characteristics of the virus are crucial in estimating its potential epidemiological impact. However, characterization of GV JEVs has so far been limited to two strains: Muar, the original isolate, and XZ0934, isolated in China. Two additional ROK GV JEV isolates, NCCP 43279 and NCCP 43413, are currently available, but their characteristics have not been explored. Our phylogenetic analysis revealed that GV virus sequences from the ROK segregate into two clades. NCCP 43279 and NCCP 43413 belong to different clades and exhibit distinct in vitro phenotypes. NCCP 43279 forms larger plaques but demonstrates inefficient propagation in cell culture compared to NCCP 43413. In vivo, NCCP 43279 induces higher morbidity and mortality in mice than NCCP 43413. Notably, NCCP 43279 shows more severe blood-brain barrier damage, suggesting superior brain invasion capabilities. Consistent with its higher virulence, NCCP 43279 displays more pronounced histopathological and immunopathological outcomes. In conclusion, our study confirms that the two ROK isolates are not only classified into different clades but also exhibit distinct in vitro and in vivo characteristics.
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Affiliation(s)
- Ah-Ra Lee
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sang-Hyun Kim
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Su-Yeon Hong
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sang-Ho Lee
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Jae Sang Oh
- Department of Neurosurgery, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Kyung Yong Lee
- Division of Cancer Biology, Research Institute, National Cancer Center, Goyang, Republic of Korea
| | - Seong-Jun Kim
- Center for Infectious Disease Vaccine and Diagnosis Innovation (CEVI), Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea
| | - Tomohiro Ishikawa
- Department of Microbiology, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Sang-Mu Shim
- Division of Acute Virus Diseases, Korea National Institute of Health, Korea Disease Control and Prevention Agency, Cheongju, Republic of Korea
| | - Hee Il Lee
- Division of Vectors and Parasitic Diseases, Korea Disease Control and Prevention Agency, Cheongju, Republic of Korea
| | - Sang-Uk Seo
- Department of Biomedicine & Health Sciences, Graduate School, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Microbiology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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Kim S, Kim MS, Nowakowska A, Choi H, Bang HW, Kim YB, Lee HJ. Generation of rescued Japanese encephalitis virus genotype 1 from infectious full-size clone using reverse genetics. Heliyon 2024; 10:e33142. [PMID: 39040327 PMCID: PMC11261045 DOI: 10.1016/j.heliyon.2024.e33142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 06/14/2024] [Accepted: 06/14/2024] [Indexed: 07/24/2024] Open
Abstract
Japanese encephalitis virus (JEV) is a pathogen responsible for high mortality and morbidity rates among children with encephalitis. Since JEV genotype 1 (GI) is the most prevalent strain in South Korea these days, corresponding research and vaccine development is urgently required. Molecular genetic studies on JEV vaccines can be boosted by obtaining genetically stable full-length infectious JEV complementary DNA (cDNA) clones. Furthermore, the significance of the reverse genetics system in facilitating molecular biological analyses of JEV properties has been demonstrated. This study constructed a recombinant JEV-GI strain using a reverse genetics system based on a Korean wild-type GI isolate (K05GS). RNA extracted from JEV-GI was used to synthesize cDNA, a recombinant full-length JEV clone, pTRE-JEVGI, was generated from the DNA fragment, and the virus was rescued. We performed in vitro and in vivo experiments to analyze the rescued JEV-GI virus. The rescued JEV-GI exhibited similar characteristics to wild-type JEV. These results suggest that our reverse genetics system can generate full-length infectious clones that can be used to analyze molecular biological factors that influence viral properties and immunogenicity. Additionally, it may be useful as a heterologous gene expression vector and help develop new strains for JEV vaccines.
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Affiliation(s)
- Sehyun Kim
- Department of Bio-industrial Technologies, Konkuk University, Seoul, 05029, Republic of Korea
| | - Min Sun Kim
- Department of Biological Sciences, Kongju National University, Chungcheongnam-do, 32588, Republic of Korea
| | - Aleksandra Nowakowska
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, 05029, Republic of Korea
| | - Heejae Choi
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, 05029, Republic of Korea
| | - Hee Won Bang
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, 05029, Republic of Korea
| | - Young Bong Kim
- Department of Bio-industrial Technologies, Konkuk University, Seoul, 05029, Republic of Korea
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, 05029, Republic of Korea
| | - Hee-Jung Lee
- Department of Biomedical Science and Engineering, Konkuk University, Seoul, 05029, Republic of Korea
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Sistrom M, Andrews H, Edwards DL. Comparative genomics of Japanese encephalitis virus shows low rates of recombination and a small subset of codon positions under episodic diversifying selection. PLoS Negl Trop Dis 2024; 18:e0011459. [PMID: 38295106 PMCID: PMC10861042 DOI: 10.1371/journal.pntd.0011459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 02/12/2024] [Accepted: 01/11/2024] [Indexed: 02/02/2024] Open
Abstract
Orthoflavivirus japonicum (JEV) is the dominant cause of viral encephalitis in the Asian region with 100,000 cases and 25,000 deaths reported annually. The genome is comprised of a single polyprotein that encodes three structural and seven non-structural proteins. We collated a dataset of 349 complete genomes from a number of public databases, and analysed the data for recombination, evolutionary selection and phylogenetic structure. There are low rates of recombination in JEV, subsequently recombination is not a major evolutionary force shaping JEV. We found a strong overall signal of purifying selection in the genome, which is the main force affecting the evolutionary dynamics in JEV. There are also a small number of genomic sites under episodic diversifying selection, especially in the envelope protein and non-structural proteins 3 and 5. Overall, these results support previous analyses of JEV evolutionary genomics and provide additional insight into the evolutionary processes shaping the distribution and adaptation of this important pathogenic arbovirus.
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Affiliation(s)
- Mark Sistrom
- Department of Industry, Trade and Tourism, Berrimah Veterinary Laboratories, Darwin, Australia
- Research Institute for the Environment and Livelihoods, Faculty of Science and Technology, Charles Darwin University, Casuarina, Australia
| | - Hannah Andrews
- Department of Industry, Trade and Tourism, Berrimah Veterinary Laboratories, Darwin, Australia
| | - Danielle L. Edwards
- Research Institute for the Environment and Livelihoods, Faculty of Science and Technology, Charles Darwin University, Casuarina, Australia
- Department of Natural Sciences, Museum and Art Gallery of the Northern Territory, Darwin, Australia
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Wahaab A, Zhang Y, Rasgon JL, Kang L, Hameed M, Li C, Anwar MN, Zhang Y, Shoaib A, Liu K, Lee B, Wei J, Qiu Y, Ma Z. NS2B-D55E and NS2B-E65D Variations are Responsible for Differences in NS2B-NS3 Protease Activities Between Japanese Encephalitis Virus Genotype I and III in Fluorogenic Peptide Model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.08.570834. [PMID: 38105993 PMCID: PMC10723430 DOI: 10.1101/2023.12.08.570834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Japanese Encephalitis Virus (JEV) NS2B-NS3 is a protein complex composed of NS3 proteases and a NS2B cofactor. The N-terminal protease domain (180 residues) of NS3 (NS3(pro)) interacts directly with a central 40-amino acid hydrophilic domain of NS2B (NS2B(H)) to form an active serine protease. In this study, the recombinant NS2B(H)-NS3(pro) proteases were prepared in E. coli and used to compare the enzymatic activity between genotype I (GI) and III (GIII) NS2B-NS3 proteases. The GI NS2B(H)-NS3(pro) was able to cleave the sites at internal C, NS2A/NS2B, NS2B/NS3 and NS3/NS4A junctions that were identical to the sites proteolytically processed by GIII NS2B(H)-NS3(pro). Analysis of the enzymatic activity of recombinant NS2B(H)-NS3(pro) proteases using a model of fluorogenic peptide substrate revealed that the proteolytical processing activity of GIII NS2B(H)-NS3(pro) was significantly higher than that of GI NS2B(H)-NS3(pro). There were eight amino acid variations between GI and GIII NS2B(H)-NS3(pro), which may be responsible for the difference in enzymatic activities between GI and GIII proteases. Therefore, recombinant mutants were generated by exchanging NS2B(H) and NS3(pro) domains between GI and GIII NS2B(H)-NS3(pro) and subjected to protease activity analysis. Substitution of NS2B(H) significantly altered the protease activities, as compared to the parental NS2B(H)-NS3(pro), suggesting that NS2B(H) played an essential role in regulation of NS3(pro) protease activity. To further identify the amino acids responsible for the difference in protease activities, multiple substitution mutants including the individual and combined mutations at the variant residue 55 and 65 of NS2B(H) were generated and subjected to protease activity analysis. Replacement of NS2B-55 and NS2B-65 of GI to GIII significantly increased the enzymatic activity of GI NS2B(H)-NS3(pro) protease, whereas mutation of NS2B-55 and NS2B-65 of GIII to GI remarkably reduced the enzymatic activity of GIII NS2B(H)-NS3(pro) protease. Overall, these data demonstrated that NS2B-55 and NS2B-65 variations in hydrophilic domain of NS2B co-contributed to the difference in NS2B(H)-NS3(pro) protease activities between GI and GIII. These observations gain an insight into the role of NS2B in regulation of NS3 protease activities, which is useful for understanding the replication of JEV GI and GIII viruses.
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Affiliation(s)
- Abdul Wahaab
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
- The Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, United States
| | - Yan Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Jason L. Rasgon
- The Department of Entomology, Center for Infectious Disease Dynamics, and the Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, United States
| | - Lei Kang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Muddassar Hameed
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
- Department of Biomedical Science and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Chenxi Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| | - Muhammad Naveed Anwar
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Yanbing Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
- College of Animal Science and Technology, Shihezi University, Shihezi, 832003, China
| | - Anam Shoaib
- School of Behavior and Brain Sciences, University of Texas at Dallas, TX, United States
| | - Ke Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Beibei Lee
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Jianchao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Yafeng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
| | - Zhiyong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China
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Xia Q, Yang Y, Zhang Y, Zhou L, Ma X, Xiao C, Zhang J, Li Z, Liu K, Li B, Shao D, Qiu Y, Wei J, Ma Z. Shift in dominant genotypes of Japanese encephalitis virus and its impact on current vaccination strategies. Front Microbiol 2023; 14:1302101. [PMID: 38045034 PMCID: PMC10690641 DOI: 10.3389/fmicb.2023.1302101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/01/2023] [Indexed: 12/05/2023] Open
Abstract
Japanese encephalitis (JE) is a zoonotic ailment from the Japanese encephalitis virus (JEV). JEV belongs to the flavivirus genus and is categorized into a solitary serotype consisting of five genetically diverse genotypes (I, II, III, IV, and V). The JEV genotype III (GIII) was the prevailing strain responsible for multiple outbreaks in countries endemic to JEV until 1990. In recent years, significant improvements have occurred in the epidemiology of JE, encompassing the geographical expansion of the epidemic zone and the displacement of prevailing genotypes. The dominant genotype of the JEV has undergone a progressive shift from GIII to GI due to variations in its adaptability within avian populations. From 2021 to 2022, Australia encountered an epidemic of viral encephalitis resulting from infection with the GIV JEV pathogen. The current human viral encephalitis caused by GIV JEV is the initial outbreak since its initial discovery in Indonesia during the late 1970s. Furthermore, following a time frame of 50 years, the detection and isolation of GV JEV have been reported in Culex mosquitoes across China and South Korea. Evidence suggests that the prevalence of GIV and GV JEV epidemic regions may be on the rise, posing a significant threat to public safety and the sustainable growth of animal husbandry. The global approach to preventing and managing JE predominantly revolves around utilizing the GIII strain vaccine for vaccination purposes. Nevertheless, research has demonstrated that the antibodies generated by the GIII strain vaccine exhibit limited capacity to neutralize the GI and GV strains. Consequently, these antibodies cannot protect against JEV challenge caused by animal GI and GV strains. The limited cross-protective and neutralizing effects observed between various genotypes may be attributed to the low homology of the E protein with other genotypes. In addition, due to the GIV JEV outbreak in Australia, further experiments are needed to evaluate the protective efficiency of the current GIII based JE vaccine against GIV JEV. The alteration of the prevailing genotype of JEV and the subsequent enlargement of the geographical extent of the epidemic have presented novel obstacles in JE prevention and control. This paper examines the emerging features of the JE epidemic in recent years and the associated problems concerning prevention and control.
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Affiliation(s)
- Qiqi Xia
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yang Yang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yan Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Lujia Zhou
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Xiaochun Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Changguang Xiao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Junjie Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Zongjie Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Ke Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Beibei Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Donghua Shao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yafeng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Jianchao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Zhiyong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
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Dong N, Zhang X, Zhang H, Zheng J, Qiu Y, Li Z, Li B, Liu K, Shao D, Ma Z, Wei J. Genotype Change in Circulating JEV Strains in Fujian Province, China. Viruses 2023; 15:1822. [PMID: 37766229 PMCID: PMC10536422 DOI: 10.3390/v15091822] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 08/25/2023] [Accepted: 08/25/2023] [Indexed: 09/29/2023] Open
Abstract
Japanese encephalitis (JE), found in pigs, is a serious mosquito-borne zoonotic infectious disease caused by the Japanese encephalitis virus (JEV). JEV is maintained in an enzootic cycle between mosquitoes and amplifying vertebrate hosts, mainly pigs and wading birds. It is transmitted to humans through the bite of an infected mosquito, allowing the pathogen to spread and cause disease epidemics. However, there is little research on JEV genotype variation in mosquitoes and pigs in Fujian province. Previous studies have shown that the main epidemic strain of JEV in Fujian Province is genotype III. In this study, a survey of mosquito species diversity in pig farms and molecular evolutionary analyses of JEV were conducted in Fujian, China, in the summer of 2019. A total of 19,177 mosquitoes were collected at four sites by UV trap. Four genera were identified, of which the Culex tritaeniorhynchus was the most common mosquito species, accounting for 76.4% of the total (14,651/19,177). Anopheles sinensi (19.25%, 3691/19,177) was the second largest species. High mosquito infection rateswere an important factor in the outbreak. The captured mosquito samples were milled and screened with JEV-specific primers. Five viruses were isolated, FJ1901, FJ1902, FJ1903, FJ1904, and FJ1905. Genetic affinity was determined by analyzing the envelope (E) gene variants. The results showed that they are JEV gene type I and most closely related to the strains SH-53 and SD0810. In this study, it was found through genetic evolution analysis that the main epidemic strain of JE in pig farms changed from gene type III to gene type I. Compared with the SH-53 and SD0810 strains, we found no change in key sites related to antigenic activity and neurovirulence of JEV in Fujian JEV and pig mosquito strains, respectively. The results of the study provide basic data for analyzing the genotypic shift of JEV in Fujian Province and support the prevention and control of JEV.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Zhiyong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (N.D.); (X.Z.); (H.Z.); (J.Z.); (Y.Q.); (Z.L.); (B.L.); (K.L.); (D.S.)
| | - Jianchao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai 200241, China; (N.D.); (X.Z.); (H.Z.); (J.Z.); (Y.Q.); (Z.L.); (B.L.); (K.L.); (D.S.)
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Dong HL, He MJ, Wang QY, Cui JZ, Chen ZL, Xiong XH, Zhang LC, Cheng H, Xiong GQ, Hu A, Lu YY, Cheng CL, Meng ZX, Zhu C, Zhao G, Liu G, Chen HP. Rapid Generation of Recombinant Flaviviruses Using Circular Polymerase Extension Reaction. Vaccines (Basel) 2023; 11:1250. [PMID: 37515065 PMCID: PMC10383701 DOI: 10.3390/vaccines11071250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
The genus Flavivirus is a group of arthropod-borne single-stranded RNA viruses, which includes important human and animal pathogens such as Japanese encephalitis virus (JEV), Zika virus (ZIKV), Dengue virus (DENV), yellow fever virus (YFV), West Nile virus (WNV), and Tick-borne encephalitis virus (TBEV). Reverse genetics has been a useful tool for understanding biological properties and the pathogenesis of flaviviruses. However, the conventional construction of full-length infectious clones for flavivirus is time-consuming and difficult due to the toxicity of the flavivirus genome to E. coli. Herein, we applied a simple, rapid, and bacterium-free circular polymerase extension reaction (CPER) method to synthesize recombinant flaviviruses in vertebrate cells as well as insect cells. We started with the de novo synthesis of the JEV vaccine strain SA-14-14-2 in Vero cells using CPER, and then modified the CPER method to recover insect-specific flaviviruses (ISFs) in mosquito C6/36 cells. Chimeric Zika virus (ChinZIKV) based on the Chaoyang virus (CYV) backbone and the Culex flavivirus reporter virus expressing green fluorescent protein (CxFV-GFP) were subsequently rescued in C6/36 cells. CPER is a simple method for the rapid generation of flaviviruses and other potential RNA viruses. A CPER-based recovery system for flaviviruses of different host ranges was established, which would facilitate the development of countermeasures against flavivirus outbreaks in the future.
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Affiliation(s)
- Hao-Long Dong
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Mei-Juan He
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Qing-Yang Wang
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Jia-Zhen Cui
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Zhi-Li Chen
- Academy of Military Medical Sciences, Beijing 100071, China
| | | | | | - Hao Cheng
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Guo-Qing Xiong
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230000, China
| | - Ao Hu
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230000, China
| | - Yuan-Yuan Lu
- Institutes of Physical Science and Information Technology, Anhui University, Hefei 230000, China
| | - Chun-Lin Cheng
- School of Life Science, Hebei University, Baoding 071000, China
| | - Zhi-Xin Meng
- School of Life Science, Hebei University, Baoding 071000, China
| | - Chen Zhu
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Guang Zhao
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Gang Liu
- Academy of Military Medical Sciences, Beijing 100071, China
| | - Hui-Peng Chen
- Academy of Military Medical Sciences, Beijing 100071, China
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Li C, Zhang L, Chen X, Jiang D, Hu J, Guo J, Ding J, Jiao X, Bao W, Li Y. Evaluation of the genotype I Japanese encephalitis virus as a stable viral vector for foreign gene expression. Antiviral Res 2023:105652. [PMID: 37301446 DOI: 10.1016/j.antiviral.2023.105652] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/31/2023] [Accepted: 06/03/2023] [Indexed: 06/12/2023]
Abstract
Manipulation of the flavivirus genome to accommodate and express a heterologous gene of interest has become an attractive approach for gene delivery and the development of viral-vectored vaccines. However, due to the inherent genetic instability of the flavivirus genomes, the construction of recombinant viruses carrying a foreign gene could be problematic and heavily resistant. In this study, the possibility of the Japanese encephalitis virus (JEV) as a stable flavivirus vector for the expression of a foreign gene was assessed using reverse genetics. The full-length cDNA genome of genotype I (GI) JEV inherently possessed excellent stability and manipulability in a bacterial host, while mutations and deletions accumulated in the cDNA genomes of genotype Ⅲ (GⅢ) JEV strains. Using the GI JEV as backbones, we generate a panel of recombinant viruses expressing various foreign genes. All recombinant viruses exhibited excellent genetic stability and efficiently express foreign genes for at least ten serial passages in vitro. In application, a convenient, rapid and reliable image-based assay for neutralizing antibody testing and antiviral drug discovery was established with a mCherry-reporter recombinant virus (rBJ-mCherry). Meanwhile, the recombinant viruses expressing the antigens of the African swine fever virus (ASFV) or Classical swine fever virus (CSFV) could effectively induce antibody responses to the JEV vector and foreign antigens in a mouse vaccination model. Therefore, GI JEV strains could serve as viral vectors accommodating the expression of large foreign genes.
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Affiliation(s)
- Chenxi Li
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China; Comparative Medicine Research Institute, Yangzhou University, Yangzhou, 225009, China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China
| | - Linjie Zhang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Xuan Chen
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Daoyuan Jiang
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Jingbo Hu
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Jinyao Guo
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Jingjing Ding
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Xue Jiao
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China
| | - Wenbin Bao
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Yanhua Li
- College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, China; Comparative Medicine Research Institute, Yangzhou University, Yangzhou, 225009, China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.
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Bhattacharjee S, Ghosh D, Saha R, Sarkar R, Kumar S, Khokhar M, Pandey RK. Mechanism of Immune Evasion in Mosquito-Borne Diseases. Pathogens 2023; 12:pathogens12050635. [PMID: 37242305 DOI: 10.3390/pathogens12050635] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
In recent decades, mosquito-borne illnesses have emerged as a major health burden in many tropical regions. These diseases, such as malaria, dengue fever, chikungunya, yellow fever, Zika virus infection, Rift Valley fever, Japanese encephalitis, and West Nile virus infection, are transmitted through the bite of infected mosquitoes. These pathogens have been shown to interfere with the host's immune system through adaptive and innate immune mechanisms, as well as the human circulatory system. Crucial immune checkpoints such as antigen presentation, T cell activation, differentiation, and proinflammatory response play a vital role in the host cell's response to pathogenic infection. Furthermore, these immune evasions have the potential to stimulate the human immune system, resulting in other associated non-communicable diseases. This review aims to advance our understanding of mosquito-borne diseases and the immune evasion mechanisms by associated pathogens. Moreover, it highlights the adverse outcomes of mosquito-borne disease.
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Affiliation(s)
| | - Debanjan Ghosh
- Department of Biotechnology, Pondicherry University, Puducherry 605014, India
| | - Rounak Saha
- Department of Biochemistry and Molecular Biology, Pondicherry University, Puducherry 605014, India
| | - Rima Sarkar
- DBT Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India
| | - Saurav Kumar
- DBT Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India
| | - Manoj Khokhar
- Department of Biochemistry, AIIMS, Jodhpur 342005, India
| | - Rajan Kumar Pandey
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 77 Solna, Sweden
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Zhao G, Gao Y, Shi N, Zhang S, Xiao P, Zhang J, Xie C, Ha Z, Feng S, Li C, Zhang X, Xie Y, Yu N, Zhang H, Bi J, Jin N. Molecular Detection and Genetic Characterization of Japanese Encephalitis Virus in Animals from 11 Provinces in China. Viruses 2023; 15:v15030625. [PMID: 36992334 PMCID: PMC10051441 DOI: 10.3390/v15030625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/14/2023] [Accepted: 02/20/2023] [Indexed: 03/03/2023] Open
Abstract
Japanese encephalitis virus (JEV), which uses a mosquito primary vector and swine as a reservoir host, poses a significant risk to human and animal health. JEV can be detected in cattle, goats and dogs. A molecular epidemiological survey of JEV was conducted in 3105 mammals from five species, swine, fox, racoon dog, yak and goat, and 17,300 mosquitoes from 11 Chinese provinces. JEV was detected in pigs from Heilongjiang (12/328, 3.66%), Jilin (17/642, 2.65%), Shandong (14/832, 1.68%), Guangxi (8/278, 2.88%) and Inner Mongolia (9/952, 0.94%); in goats (1/51, 1.96%) from Tibet; and mosquitoes (6/131, 4.58%) from Yunnan. A total of 13 JEV envelope (E) gene sequences were amplified in pigs from Heilongjiang (5/13), Jilin (2/13) and Guangxi (6/13). Swine had the highest JEV infection rate of any animal species, and the highest infection rates were found in Heilongjiang. Phylogenetic analysis indicated that the predominant strain in Northern China was genotype I. Mutations were found at residues 76, 95, 123, 138, 244, 474 and 475 of E protein but all sequences had predicted glycosylation sites at ′N154. Three strains lacked the threonine 76 phosphorylation site from non-specific (unsp) and protein kinase G (PKG) site predictions; one lacked the threonine 186 phosphorylation site from protein kinase II (CKII) prediction; and one lacked the tyrosine 90 phosphorylation site from epidermal growth factor receptor (EGFR) prediction. The aim of the current study was to contribute to JEV prevention and control through the characterization of its molecular epidemiology and prediction of functional changes due to E-protein mutations.
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Affiliation(s)
- Guanyu Zhao
- College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Yan Gao
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Ning Shi
- College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Shiheng Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Pengpeng Xiao
- Wenzhou Key Laboratory for Virology and Immunology, Institute of Virology, Wenzhou University, Wenzhou 325035, China
| | - Jiaqi Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Changzhan Xie
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Zhuo Ha
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Sheng Feng
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Chenghui Li
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Xuancheng Zhang
- College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - Yubiao Xie
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
| | - Ning Yu
- College of Veterinary Medicine, Jilin University, Changchun 130062, China
| | - He Zhang
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Correspondence: (H.Z.); (J.B.); (N.J.)
| | - Junlong Bi
- College of Animal Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China
- Correspondence: (H.Z.); (J.B.); (N.J.)
| | - Ningyi Jin
- College of Veterinary Medicine, Jilin University, Changchun 130062, China
- Changchun Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Changchun 130122, China
- Correspondence: (H.Z.); (J.B.); (N.J.)
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11
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Mote AB, Mehta D, Kumar MS, Gupta M, Hussain M, Patel SM, Gandham RK, Dhanze H. Genotypic characterization of Japanese encephalitis virus circulating in swine population of India: Genotype-III still in dominance. Virus Genes 2023; 59:67-78. [PMID: 36357764 DOI: 10.1007/s11262-022-01953-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 10/29/2022] [Indexed: 11/12/2022]
Abstract
Swine is considered as a suitable sentinel to predict Japanese encephalitis virus (JEV) outbreaks in humans. The present study was undertaken to determine the circulating genotypes of JEV in swine population of India. A total of 702 swine serum samples from four states of western, northern, northern-temperate, and north-eastern zones of India were screened by real-time RT-PCR targeting envelope gene of JEV, which showed positivity of 35.33%. The viral copy number ranged from 3 copies to 6.3 × 104 copies/reaction. Subsequently, the capsid/prM structural gene region of JEV positive samples was amplified by nested RT-PCR, sequenced, and genetically characterized. The phylogenetic analysis of the partial sequences of the capsid gene of 42 JEV positive samples showed that they all belonged to genotype-III (G-III) of JEV. Notably, JEV positive swine samples showed high nucleotide identity with human isolates from China and Nepal which explains the probable spillover of infection between neighboring countries probably by migratory birds. The novel mutations were observed in JEV positive sample B8 at C54 position (Phe → Ser), and JEV positive sample K50 at C62 (Thr → Ala) and C65 (Leu → Pro) positions which were absent from other JEV isolates reported till now. The mutation at the C66 position (Leu → Ser) observed in live attenuated vaccine SA14-14-2 strain was not found in JEV positive samples of our study. The detection of the G-III JE virus from climatically diverse states of India reinforces the need to continue the ongoing human vaccination program in India by extending vaccine coverage in temperate states.
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Affiliation(s)
- Akash Balasaheb Mote
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Deepa Mehta
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - M Suman Kumar
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Megha Gupta
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Mir Hussain
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Sagar M Patel
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Ravi Kumar Gandham
- Division of Animal Biotechnology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India
| | - Himani Dhanze
- Division of Veterinary Public Health, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, India.
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A Recombinant Genotype I Japanese Encephalitis Virus Expressing a Gaussia Luciferase Gene for Antiviral Drug Screening Assay and Neutralizing Antibodies Detection. Int J Mol Sci 2022; 23:ijms232415548. [PMID: 36555192 PMCID: PMC9778660 DOI: 10.3390/ijms232415548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/05/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
Japanese encephalitis virus (JEV) is the major cause of viral encephalitis in humans throughout Asia. In the past twenty years, the emergence of the genotype I (GI) JEV as the dominant genotype in Asian countries has raised a significant threat to public health security. However, no clinically approved drug is available for the specific treatment of JEV infection, and the commercial vaccines derived from the genotype III JEV strains merely provided partial protection against the GI JEV. Thus, an easy-to-perform platform in high-throughput is urgently needed for the antiviral drug screening and assessment of neutralizing antibodies specific against the GI JEV. In this study, we established a reverse genetics system for the GI JEV strain (YZ-1) using a homologous recombination strategy. Using this reverse genetic system, a gaussia luciferase (Gluc) expression cassette was inserted into the JEV genome to generate a reporter virus (rGI-Gluc). The reporter virus exhibited similar growth kinetics to the parental virus and remained genetically stable for at least ten passages in vitro. Of note, the bioluminescence signal strength of Gluc in the culture supernatants was well correlated with the viral progenies determined by viral titration. Taking advantage of this reporter virus, we established Gluc readout-based assays for antiviral drug screening and neutralizing antibody detection against the GI JEV. These Gluc readout-based assays exhibited comparable performance to the assays using an actual virus and are less time consuming and are applicable for a high-throughput format. Taken together, we generated a GI JEV reporter virus expressing a Gluc gene that could be a valuable tool for an antiviral drug screening assay and neutralization assay.
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Japanese Encephalitis Virus: The Emergence of Genotype IV in Australia and Its Potential Endemicity. Viruses 2022; 14:v14112480. [PMID: 36366578 PMCID: PMC9698845 DOI: 10.3390/v14112480] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 11/04/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022] Open
Abstract
A fatal case of Japanese encephalitis (JE) occurred in northern Australia in early 2021. Sequence studies showed that the virus belonged to genotype IV (GIV), a genotype previously believed to be restricted to the Indonesian archipelago. This was the first locally acquired case of Japanese encephalitis virus (JEV) GIV to occur outside Indonesia, and the second confirmed fatal human case caused by a GIV virus. A closely related GIV JEV strain subsequently caused a widespread outbreak in eastern Australia in 2022 that was first detected by fetal death and abnormalities in commercial piggeries. Forty-two human cases also occurred with seven fatalities. This has been the first major outbreak of JEV in mainland Australia, and geographically the largest virgin soil outbreak recorded for JEV. This outbreak provides an opportunity to discuss and document the factors involved in the virus' spread and its ecology in a novel ecological milieu in which other flaviviruses, including members of the JE serological complex, also occur. The probable vertebrate hosts and mosquito vectors are discussed with respect to virus spread and its possible endemicity in Australia, and the need to develop a One Health approach to develop improved surveillance methods to rapidly detect future outbreak activity across a large geographical area containing a sparse human population. Understanding the spread of JEV in a novel ecological environment is relevant to the possible threat that JEV may pose in the future to other receptive geographic areas, such as the west coast of the United States, southern Europe or Africa.
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Evaluation of dogs (Canis familiaris) as an indicator of Japanese encephalitis (JE) outbreaks: A retrospective serological study in the Seoul metropolitan area around the 2010 resurgence of JE in the Republic of Korea. One Health 2022; 15:100459. [DOI: 10.1016/j.onehlt.2022.100459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/15/2022] [Accepted: 11/15/2022] [Indexed: 11/18/2022] Open
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Aure WE, Sayama Y, Saito-Obata M, Salazar NP, Malbas FF, Galang HO, Imamura T, Zuasula CL, Oshitani H. Japanese encephalitis virus genotype III from mosquitoes in Tarlac, Philippines. IJID REGIONS 2022; 4:59-65. [PMID: 36093364 PMCID: PMC9453045 DOI: 10.1016/j.ijregi.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 05/12/2022] [Accepted: 05/12/2022] [Indexed: 11/27/2022]
Abstract
Japanese encephalitis is endemic in the Philippines. Japanese encephalitis virus genotype III was detected in Culex tritaeniorhynchus. Mosquitoes breed in inundated rice fields close to human habitation. Epidemiological surveillance and immunization of children are identified needs.
Objectives The aim of this study was to investigate the presence of Japanese encephalitis virus (JEV) in a rice-farming community in the Philippines and to determine its implications regarding the epidemiology of viral encephalitides in the Asia-Pacific Region. Methods Mosquitoes were collected monthly from animal-baited traps close to flooded rice fields in two barangays (villages) in the Municipality of San Jose, Tarlac Province in Luzon, from May 2009 to July 2010. Virus was detected by nested reverse transcription PCR. Phylogenetic analysis of the amplified virus envelope gene was done using the maximum-likelihood method. Results A total of 28 700 known vector mosquitoes were collected, namely Culex vishnui, Culex fuscocephala, Culex tritaeniorhynchus, and Culex gelidus. JEV genotype III was detected in C. tritaeniorhynchus, belonging to the same genotype but form a different clade from those reported in the 1980s and in 2020 in this country. Conclusions Japanese encephalitis is associated with rice cultivation and the presence of infected mosquitoes in Tarlac, Philippines. It remains to be seen whether the observed genetic shift of genotype III to genotype I in Asia will in time have an impact on the epidemiology of Japanese encephalitis in the Philippines. For long-term disease control, regular surveillance and Japanese encephalitis immunization in children and travelers in high risk areas are recommended.
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Sun Y, Ding H, Zhao F, Yan Q, Li Y, Niu X, Zeng W, Wu K, Ling B, Fan S, Zhao M, Yi L, Chen J. Genomic Characteristics and E Protein Bioinformatics Analysis of JEV Isolates from South China from 2011 to 2018. Vaccines (Basel) 2022; 10:vaccines10081303. [PMID: 36016192 PMCID: PMC9412759 DOI: 10.3390/vaccines10081303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/03/2022] [Accepted: 08/09/2022] [Indexed: 11/16/2022] Open
Abstract
Japanese encephalitis is a mosquito-borne zoonotic epidemic caused by the Japanese encephalitis virus (JEV). JEV is not only the leading cause of Asian viral encephalitis, but also one of the leading causes of viral encephalitis worldwide. To understand the genetic evolution and E protein characteristics of JEV, 263 suspected porcine JE samples collected from South China from 2011 to 2018 were inspected. It was found that 78 aborted porcine fetuses were JEV-nucleic-acid-positive, with a positive rate of 29.7%. Furthermore, four JEV variants were isolated from JEV-nucleic-acid-positive materials, namely, CH/GD2011/2011, CH/GD2014/2014, CH/GD2015/2015, and CH/GD2018/2018. The cell culture and virus titer determination of four JEV isolates showed that four JEV isolates could proliferate stably in Vero cells, and the virus titer was as high as 108.5 TCID 50/mL. The whole-genome sequences of four JEV isolates were sequenced. Based on the phylogenetic analysis of the JEV E gene and whole genome, it was found that CH/GD2011/2011 and CH/GD2015/2015 belonged to the GIII type, while CH/GD2014/2014 and CH/GD2018/2018 belonged to the GI type, which was significantly different from that of the JEV classical strain CH/BJ-1/1995. Bioinformatics tools were used to analyze the E protein phosphorylation site, glycosylation site, B cell antigen epitope, and modeled 3D structures of E protein in four JEV isolates. The analysis of the prevalence of JEV and the biological function of E protein can provide a theoretical basis for the prevention and control of JEV and the design of antiviral drugs.
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Affiliation(s)
- Yawei Sun
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Hongxing Ding
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Feifan Zhao
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Quanhui Yan
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Yuwan Li
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Xinni Niu
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Weijun Zeng
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
| | - Keke Wu
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Bing Ling
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Shuangqi Fan
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Mingqiu Zhao
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Lin Yi
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
| | - Jinding Chen
- Department of Microbiology and Immunology, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China
- Key Laboratory of Zoonosis Prevention and Control of Guangdong Province, Guangzhou 510642, China
- Correspondence: ; Fax: +86-20-8528-0245
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Yu X, Cheng G. Adaptive Evolution as a Driving Force of the Emergence and Re-Emergence of Mosquito-Borne Viral Diseases. Viruses 2022; 14:v14020435. [PMID: 35216028 PMCID: PMC8878277 DOI: 10.3390/v14020435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/16/2022] [Accepted: 02/18/2022] [Indexed: 02/06/2023] Open
Abstract
Emerging and re-emerging mosquito-borne viral diseases impose a significant burden on global public health. The most common mosquito-borne viruses causing recent epidemics include flaviviruses in the family Flaviviridae, including Dengue virus (DENV), Zika virus (ZIKV), Japanese encephalitis virus (JEV) and West Nile virus (WNV) and Togaviridae viruses, such as chikungunya virus (CHIKV). Several factors may have contributed to the recent re-emergence and spread of mosquito-borne viral diseases. Among these important causes are the evolution of mosquito-borne viruses and the genetic mutations that make them more adaptive and virulent, leading to widespread epidemics. RNA viruses tend to acquire genetic diversity due to error-prone RNA-dependent RNA polymerases, thus promoting high mutation rates that support adaptation to environmental changes or host immunity. In this review, we discuss recent findings on the adaptive evolution of mosquito-borne viruses and their impact on viral infectivity, pathogenicity, vector fitness, transmissibility, epidemic potential and disease emergence.
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Affiliation(s)
- Xi Yu
- Tsinghua-Peking Center for Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China;
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen 518000, China
- School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Gong Cheng
- Tsinghua-Peking Center for Life Sciences, School of Medicine, Tsinghua University, Beijing 100084, China;
- Institute of Infectious Diseases, Shenzhen Bay Laboratory, Shenzhen 518000, China
- Institute of Pathogenic Organisms, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
- Correspondence:
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Novel reverse genetics of genotype I and III Japanese encephalitis viruses assembled through transformation associated recombination in yeast: The reporter viruses expressing a green fluorescent protein for the antiviral screening assay. Antiviral Res 2022; 197:105233. [DOI: 10.1016/j.antiviral.2021.105233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/22/2021] [Accepted: 12/26/2021] [Indexed: 11/24/2022]
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Chiou SS, Chen JM, Chen YY, Chia MY, Fan YC. The feasibility of field collected pig oronasal secretions as specimens for the virologic surveillance of Japanese encephalitis virus. PLoS Negl Trop Dis 2021; 15:e0009977. [PMID: 34860839 PMCID: PMC8673640 DOI: 10.1371/journal.pntd.0009977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 12/15/2021] [Accepted: 11/05/2021] [Indexed: 11/24/2022] Open
Abstract
Virologic surveillance of Japanese encephalitis virus (JEV) relies on collecting pig blood specimens and adult mosquitoes in the past. Viral RNAs extracted from pig blood specimens suffer from low detecting positivity by reverse transcription PCR (RT-PCR). The oronasal transmission of the virus has been demonstrated in experimentally infected pigs. This observation suggested oronasal specimens could be useful source in the virus surveillance. However, the role of this unusual route of transmission remains unproven in the operational pig farm. In this study, we explore the feasibility of using pig oronasal secretions collected by chewing ropes to improve the positivity of detection in commercial pig farms. The multiplex genotype-specific RT-PCR was used in this study to determine and compare the positivity of detecting JEV viral RNAs in pig’s oronasal secretions and blood specimens, and the primary mosquito vector. Oronasal specimens had the overall positive rate of 6.0% (95% CI 1.3%–16.6%) (3/50) to 10.0% (95% CI 2.1%–26.5%) (3/30) for JEV during transmission period despite the negative results of all blood-derived specimens (n = 2442). Interestingly, pig oronasal secretions and female Culex tritaeniorhynchus mosquito samples collected from the same pig farm showed similar viral RNA positive rates, 10.0% (95% CI 2.1%–26.5%) (3/30) and 8.9% (95% CI 2.5%–21.2%) (4/45), respectively (p> 0.05). Pig oronasal secretion-based surveillance revealed the seasonality of viral activity and identified closely related genotype I virus derived from the mosquito isolates. This finding indicates oronasal secretion-based RT-PCR assay can be a non-invasive, alternative method of implementing JEV surveillance in the epidemic area prior to the circulation of virus-positive mosquitoes. Mosquito-borne Japanese encephalitis virus (JEV) has either endemic or seasonal patterns of transmission in Asia and Australia. Most hosts infected by the virus remains asymptomatic but can result in severe encephalitis in humans and horses, and abortion or stillbirth in pregnant sows. Isolation of virus in adult mosquitoes or pig seroconversion has been used as an early indicator of upcoming JE outbreak in humans. Genotype identification of the virus is important since current human and domestic animal vaccines are all genotype III (GIII) specific. GIII vaccine elicited immunity has reduced cross-protections to genotypes other than GIII. Our virologic surveillance using pig’s oronasal secretion detected higher prevalence and earlier genotype I virus activity than using pig’s blood and mosquitoes, respectively. This proposed surveillance tool might be more effective that will allow the public health agency to properly implement the preventive measures, such as implementing mosquito control, encouraging booster vaccination, and encouraging the use of mosquito repellent, to reduce the impact of upcoming outbreak. Collection of pig’s oronasal secretion is non-invasive to pigs and less technically demanding to operators. Thus we propose the use of pig’s oronasal secretions as the novel source of specimens for virologic surveillance to replace the traditional pig blood or adult mosquito specimens to monitor and control JE outbreak/epidemic in the future.
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Affiliation(s)
- Shyan-Song Chiou
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Jo-Mei Chen
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Ying Chen
- Graduate Institute of Microbiology and Public Health, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Min-Yuan Chia
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Chin Fan
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
- * E-mail:
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Mulvey P, Duong V, Boyer S, Burgess G, Williams DT, Dussart P, Horwood PF. The Ecology and Evolution of Japanese Encephalitis Virus. Pathogens 2021; 10:1534. [PMID: 34959489 PMCID: PMC8704921 DOI: 10.3390/pathogens10121534] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/16/2021] [Accepted: 11/18/2021] [Indexed: 11/16/2022] Open
Abstract
Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus mainly spread by Culex mosquitoes that currently has a geographic distribution across most of Southeast Asia and the Western Pacific. Infection with JEV can cause Japanese encephalitis (JE), a severe disease with a high mortality rate, which also results in ongoing sequalae in many survivors. The natural reservoir of JEV is ardeid wading birds, such as egrets and herons, but pigs commonly play an important role as an amplifying host during outbreaks in human populations. Other domestic animals and wildlife have been detected as hosts for JEV, but their role in the ecology and epidemiology of JEV is uncertain. Safe and effective JEV vaccines are available, but unfortunately, their use remains low in most endemic countries where they are most needed. Increased surveillance and diagnosis of JE is required as climate change and social disruption are likely to facilitate further geographical expansion of Culex vectors and JE risk areas.
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Affiliation(s)
- Peter Mulvey
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia;
| | - Veasna Duong
- Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 12201, Cambodia; (V.D.); (S.B.); (P.D.)
| | - Sebastien Boyer
- Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 12201, Cambodia; (V.D.); (S.B.); (P.D.)
| | - Graham Burgess
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville 4811, Australia;
| | - David T. Williams
- Australian Centre for Disease Preparedness, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Geelong 3220, Australia;
| | - Philippe Dussart
- Institut Pasteur du Cambodge, Institut Pasteur International Network, Phnom Penh 12201, Cambodia; (V.D.); (S.B.); (P.D.)
| | - Paul F. Horwood
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville 4811, Australia;
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville 4811, Australia;
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Xing J, Zhang Y, Lin Z, Liu L, Xu Q, Liang J, Yuan Z, Huang C, Liao M, Qi W. 3'UTR SL-IV and DB1 Regions Contribute to Japanese Encephalitis Virus Replication and Pathogenicity. Front Vet Sci 2021; 8:703147. [PMID: 34409089 PMCID: PMC8366024 DOI: 10.3389/fvets.2021.703147] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/07/2021] [Indexed: 11/29/2022] Open
Abstract
Japanese encephalitis virus (JEV), a mosquito-borne flavivirus that causes fatal neurological disease in humans, is one of the most important emerging pathogens of public health significance. JEV is maintained in an enzootic cycle and causes reproductive failure in pigs. Notably, the shift in JEV genotypes is not fully protected by existing vaccines, so the development of a candidate vaccine is urgently needed. In this study, we compared pathogenicity between Japanese encephalitis virus SA14 and BJB (isolated from humans in the 1970s) strains. We found that the BJB strain was attenuated in mice and that there was no case fatality rate. The growth rate of BJB was higher than SA14 virus in BHK-21 cells. Based on the sequence alignment of the viral genome between the SA14 and BJB virus strains, some mutations at sites 248, 254, 258, and 307 were observed in the 3′ untranslated region (3′UTR). The 3′UTR of JEV plays a very important role in the viral life cycle. Furthermore, using a reverse genetic system, we conducted and rescued the parental JEV strain SA14 (T248, A254, and A258) and the mutant virus rSA14-3′UTRmut (T248C, A254G, A258G, and 307G). Through an analysis of the RNA secondary structure model of the 3′UTR, we discovered that the mutations of T248C, A254G, and A258G reduced the apiculus ring and increased the lateral ring significantly in the stem-loop structures IV (SL-IV) structure region of 3′UTR. Moreover, the insertion of 307G added a ring to the dumbbell structure 1 (DB1) structure region. Strikingly, these RNA secondary structure changes in 3′UTR of rSA14-3′UTRmut increased viral negative chain RNA production and enhanced the replication ability of the virus in BHK-21 cells. However, in vivo mouse experiments illustrated that the rSA14-3′UTRmut virus significantly decreased the neurovirulence of JEV. These results affirmed that the JEV SL-IV and DB1 regions play an important role in viral proliferation and pathogenicity. Taken together, we complement the study of RNA element function in the 3′UTR region of JEV by providing a new target for the rational design of live attenuated candidate vaccines and the increase of virus production.
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Affiliation(s)
- Jinchao Xing
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Youyue Zhang
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Ziying Lin
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China
| | - Lele Liu
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China
| | - Qiang Xu
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China
| | - Jiaqi Liang
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China
| | - Zhaoxia Yuan
- College of Animal Sciences and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Cuiqin Huang
- The Key Laboratory of Fujian Animal Diseases Control, Longyan University, Longyan, China
| | - Ming Liao
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China.,Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou, China
| | - Wenbao Qi
- Key Laboratory of Zoonoses, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, China.,National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, Guangzhou, China.,Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China.,Key Laboratory of Zoonoses Prevention and Control of Guangdong Province, Guangzhou, China
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22
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Fang Y, Li XS, Zhang W, Xue JB, Wang JZ, Yin SQ, Li SG, Li XH, Zhang Y. Molecular epidemiology of mosquito-borne viruses at the China-Myanmar border: discovery of a potential epidemic focus of Japanese encephalitis. Infect Dis Poverty 2021; 10:57. [PMID: 33902684 PMCID: PMC8073957 DOI: 10.1186/s40249-021-00838-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/08/2021] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Mosquito-based arbovirus surveillance can serve as an early warning in evaluating the status of mosquito-borne virus prevalence and thus prevent local outbreaks. Although Tengchong County in Yunnan Province-which borders Myanmar-is abundant and diverse in mosquitoes, very few mosquito-based arbovirus investigations have been conducted in the recent decade. Herein, this study aims to evaluate the presence and the diffusion of mosquito-borne pathogens, currently prevalent in this region. METHODS We collected 9486 mosquitoes, representing eight species, with Culex tritaeniorhynchus and Anopheles sinensis as the dominant species, during high mosquito activity seasons (July-October) in Tengchong, in 2018. Samples collected from 342 pools were tested using reverse-transcription PCR to determine the species, distribution, and infection rates of virus and parasite, and further analyze their genotypes, phylogenetic relationships, infection rate, and potential pathogenicity. RESULTS Fifteen Japanese encephalitis virus (JEV) strains from Cx. tritaeniorhynchus pools were detected. Seven strains of insect-specific flaviviruses (ISFVs), including two Aedes flavivirus (AeFV) and Yunnan Culex flavivirus strains each, one Culex theileri flavivirus, Yamadai flavivirus (YDFV) and Anopheles-associated flavivirus (AAFV) strains each were detected in Aedes albopictus, Cx. tritaeniorhynchus, Cx. vagans, Cx. pseudovihnui, and An. sinensis pools, respectively. The whole-genome was successfully amplified in one strain of JEV and AeFV each. Phylogenetic analysis using the E gene placed all the newly detected JEV strains into the GI-b genotype. They showed highly nucleotide identities, and were most closely related to the strain detected in Tengchong in 2010. The comparison of the E protein of JEV strains and vaccine-derived strain, showed six amino residue differences. The bias-corrected maximum likelihood estimation values (and 95% confidence interval) for JEV in Cx. tritaeniorhynchus collected in Tengchong in 2018 were 2.4 (1.4-3.9). CONCLUSIONS A potential Japanese encephalitis epidemic focus with the abundance of host mosquitoes and high JEV infection rate was observed in Tengchong. In addition, at least five species of ISFVs co-circulate in this area. This study highlights the importance of widespread and sustained mosquito-based arbovirus surveillance in local areas to prevent the transmission of JEV, and other emerging/re-emerging mosquito-borne pathogens.
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Affiliation(s)
- Yuan Fang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research); NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Shanghai, China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xi-Shang Li
- Tengchong County Center for Disease Control and Prevention, Tengchong, Yunnan, China
| | - Wei Zhang
- Zichuan District Center for Disease Control and Prevention, Shandong, Zibo, China
| | - Jing-Bo Xue
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research); NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Shanghai, China
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jia-Zhi Wang
- Tengchong County Center for Disease Control and Prevention, Tengchong, Yunnan, China
| | - Shou-Qin Yin
- Zichuan District Center for Disease Control and Prevention, Shandong, Zibo, China
| | - Sheng-Guo Li
- Tengchong County Center for Disease Control and Prevention, Tengchong, Yunnan, China
| | - Xin-He Li
- Tengchong County Center for Disease Control and Prevention, Tengchong, Yunnan, China
| | - Yi Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research); NHC Key Laboratory of Parasite and Vector Biology; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Shanghai, China.
- School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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23
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Fang Y, Zhang W, Xue JB, Zhang Y. Monitoring Mosquito-Borne Arbovirus in Various Insect Regions in China in 2018. Front Cell Infect Microbiol 2021; 11:640993. [PMID: 33791242 PMCID: PMC8006455 DOI: 10.3389/fcimb.2021.640993] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 02/05/2021] [Indexed: 12/03/2022] Open
Abstract
Background Increases in global travel and trade are changing arbovirus distributions worldwide. Arboviruses can be introduced by travelers, migratory birds, or vectors transported via international trade. Arbovirus surveillance in field-collected mosquitoes may provide early evidence for mosquito-borne disease transmission. Methods During the seasons of high mosquito activity of 2018, 29,285 mosquitoes were sampled from seven sentinel sites in various insect regions. The mosquitoes were analyzed by RT-PCR for alphaviruses, flaviviruses, and orthobunyaviruses. Results We detected three strains of Japanese encephalitis virus (JEV), five strains of Getah virus (GETV), and 45 strains of insect-specific flaviviruses including Aedes flavivirus (AeFV, 1), Chaoyang virus (CHAOV, 1), Culex flavivirus (CxFV, 17), Hanko virus (HANKV, 2), QuangBinh virus (QBV, 22), and Yunnan Culex flavivirus (YNCxFV, 2). Whole genomes of one strain each of GETV, CxFV, CHAOV, and AeFV were successfully amplified. Phylogenetic analysis revealed that the new JEV strains detected in the Shanghai and Hubei Provinces belong to the GI-b strain and are phylogenetically close to the NX1889 strain (MT134112) isolated from a patient during a JE outbreak in Ningxia in 2018. GETVs were found in Inner Mongolia, Hubei, and Hainan and belonged to Group III. They were closely related to strains isolated from swine. HANKV was recorded for the first time in China and other ISFVs were newly detected at several sentinel sites. The bias-corrected maximum likelihood estimation value for JEV in Jinshan, Shanghai was 4.52/1,000 (range 0.80-14.64). Hence, there is a potential risk of a JEV epidemic in that region. Conclusion GI-b is the dominant circulating JEV genotype in nature and poses a health risk to animals and humans. The potential threat of widespread GETV distribution as a zoonosis is gradually increasing. The present study also disclosed the dispersion and host range of ISFVs. These findings highlight the importance of tracing the movements of the vectors and hosts of mosquito-borne pathogens in order to prevent and control arbovirus outbreaks in China.
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Affiliation(s)
- Yuan Fang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Chinese Center for Tropical Diseases Research, Ministry of Science and Technology, Shanghai, China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| | - Wei Zhang
- Zichuan District Center for Disease Control and Prevention, Zibo, China
| | - Jing-Bo Xue
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Chinese Center for Tropical Diseases Research, Ministry of Science and Technology, Shanghai, China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
| | - Yi Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China
- Chinese Center for Tropical Diseases Research, Ministry of Science and Technology, Shanghai, China
- Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, China
- WHO Collaborating Centre for Tropical Diseases, Shanghai, China
- National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai, China
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24
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Kuwata R, Torii S, Shimoda H, Supriyono S, Phichitraslip T, Prasertsincharoen N, Takemae H, Bautista RCJT, Ebora VDBM, Abella JAC, Dargantes AP, Hadi UK, Setiyono A, Baltazar ET, Simborio LT, Agungpriyono S, Jittapalapong S, Rerkamnuaychoke W, Hondo E, Maeda K. Distribution of Japanese Encephalitis Virus, Japan and Southeast Asia, 2016-2018. Emerg Infect Dis 2021; 26:125-128. [PMID: 31855535 PMCID: PMC6924880 DOI: 10.3201/eid2601.190235] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
During 2016–2018, we conducted surveillance for Japanese encephalitis virus (JEV) in mosquitoes and pigs in Japan, Thailand, the Philippines, and Indonesia. Phylogenetic analyses demonstrated that our isolates (genotypes Ia, Ib, III, IV) were related to JEV isolates obtained from the same regions many years ago. Indigenous JEV strains persist in Asia.
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25
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Identification of Cleavage Sites Proteolytically Processed by NS2B-NS3 Protease in Polyprotein of Japanese Encephalitis Virus. Pathogens 2021; 10:pathogens10020102. [PMID: 33494395 PMCID: PMC7911949 DOI: 10.3390/pathogens10020102] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/18/2021] [Accepted: 01/18/2021] [Indexed: 12/14/2022] Open
Abstract
Understanding the proteolytic processing of polyprotein mediated by NS2B-NS3 protease contributes to the exploration of the mechanisms underlying infection of Japanese encephalitis virus (JEV), a zoonotic flavivirus. In this study, eukaryotic and prokaryotic cell models were employed to identify the cleavage sites mediated by viral NS2B-NS3 protease in JEV polyprotein. Artificial green fluorescent protein (GFP) substrates that contained the predicted cleavage site sequences of JEV polyprotein were expressed in swine testicle (ST) cells in the presence and absence of JEV infection, or co-expressed in E. coli with the recombinant NS2B-NS3 protease that was generated by fusing the N-terminal protease domain of NS3 to the central hydrophilic domain of NS2B. The cleavage of GFP substrates was examined by western blot. Among twelve artificial GFP substrates containing the cleavage site sequences predictively processed by host cell and/or NS2B-NS3 proteases, all sites were found to be cleaved by host cell proteases with different efficiencies. The sites at internal C, NS2A/NS2B, NS2B/NS3 and NS3/NS4A junctions, but not the sites at internal NS3, internal NS4A and NS4B/NS5 junctions were identified to be cleaved by JEV NS2B-NS3 protease. These data provide insight into the proteolytic processing of polyprotein, which is useful for understanding JEV replication and pathogenesis.
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26
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Li C, Di D, Huang H, Wang X, Xia Q, Ma X, Liu K, Li B, Shao D, Qiu Y, Li Z, Wei J, Ma Z. NS5-V372A and NS5-H386Y variations are responsible for differences in interferon α/β induction and co-contribute to the replication advantage of Japanese encephalitis virus genotype I over genotype III in ducklings. PLoS Pathog 2020; 16:e1008773. [PMID: 32881988 PMCID: PMC7494076 DOI: 10.1371/journal.ppat.1008773] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 09/16/2020] [Accepted: 07/01/2020] [Indexed: 01/27/2023] Open
Abstract
Japanese encephalitis virus (JEV) genotype I (GI) replicates more efficiently than genotype III (GIII) in birds, and this difference is considered to be one of the reasons for the JEV genotype shift. In this study, we utilized duck embryo fibroblasts and domestic ducklings as in vitro and in vivo models of a JEV amplifying avian host to identify the viral determinants of the differing replication efficiency between the GI and GIII strains in birds. GI strains induced significantly lower levels of interferon (IFN)-α and β production than GIII strains, an effect orrelated with the enhanced replication efficiency of GI strains over GIII strains. By using a series of chimeric viruses with exchange of viral structural and non-structural (NS) proteins, we identified NS5 as the viral determinant of the differences in IFN-α and β induction and replication efficiency between the GI and III strains. NS5 inhibited IFN-α and β production induced by poly(I:C) stimulation and harbored 11 amino acid variations, of which the NS5-V372A and NS5-H386Y variations were identified to co-contribute to the differences in IFN-α and β induction and replication efficiency between the strains. The NS5-V372A and NS5-H386Y variations resulted in alterations in the number of hydrogen bonds formed with neighboring residues, which were associated with the different ability of the GI and GIII strains to inhibit IFN-α and β production. Our findings indicated that the NS5-V372A and NS5-H386Y variations enabled GI strains to inhibit IFN-α and β production more efficiently than GIII strains for antagonism of the IFN-I mediated antiviral response, thereby leading to the replication and host adaption advantages of GI strains over GIII strains in birds. These findings provide new insight into the molecular basis of the JEV genotype shift. The Japanese encephalitis virus (JEV) transmission cycle is maintained by mosquitoes and amplification hosts (pigs and birds). In areas without large pig populations, birds play a major role in the maintenance of the JEV transmission cycle. The shift in the dominant JEV genotype from genotype III (GIII) to genotype I (GI) is occurring in most countries in Asia. GI strains replicates more efficiently than GIII strains in birds, and this difference has been considered one of the reasons for the JEV genotype shift. By using a series of chimeric viruses with exchange of viral structural and non-structural (NS) proteins, we demonstrated that NS5 is the viral determinant of the differences in replication efficiencies between the GI and III strains in birds. Furthermore, the NS5-V372A and NS5-H386Y variations were identified to co-contribute to the differences in type I interferon (IFN-I) induction and replication efficiency between the strains. Our findings suggested that the NS5-V372A and NS5-H386Y variations enable GI strains to inhibit IFN-I production more efficiently than GIII strains, thus resulting in antagonism of the IFN-I mediated antiviral response and consequently conferring a replication and host adaption advantage to GI strains over GIII strains in birds. These findings provide new insight into the molecular basis of the JEV genotype shift.
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Affiliation(s)
- Chenxi Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Di Di
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Hui Huang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Xin Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Qiqi Xia
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Xiaochun Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Ke Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Beibei Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Donghua Shao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Yafeng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Zongjie Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Jianchao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
- * E-mail: (JW); (ZM)
| | - Zhiyong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
- * E-mail: (JW); (ZM)
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27
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Liu W, Fu S, Ma X, Chen X, Wu D, Zhou L, Yin Q, Li F, He Y, Lei W, Li Y, Xu S, Wang H, Wang Z, Wang H, Yu H, Liang G. An outbreak of Japanese encephalitis caused by genotype Ib Japanese encephalitis virus in China, 2018: A laboratory and field investigation. PLoS Negl Trop Dis 2020; 14:e0008312. [PMID: 32453787 PMCID: PMC7274457 DOI: 10.1371/journal.pntd.0008312] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 06/05/2020] [Accepted: 04/20/2020] [Indexed: 11/23/2022] Open
Abstract
Although Japanese encephalitis virus genotype Ib (JEV GIb) has replaced JEV GIII as the dominant genotype in endemic areas of Asia, no JEV GIb has been isolated from JE cases and natural mosquitoes at the same time in an outbreak of JE. In this study, we conducted virological and molecular biological laboratory tests on JE case samples (serum/cerebrospinal fluid) and locally collected mosquito samples from the 2018 JE outbreak in Ningxia, China. The result of JEV IgM antibody detection showed that 96% (67/70) of the suspected cases were laboratory-confirmed JE cases. Of the mosquitoes collected from local environments, 70% (17400/24900) were Culex tritaeniorhynchus of which 4.6% (16 /348 of the pools tested) were positive for JEV, other mosquitoes were negative. JEVs isolated from both the human cases and C. tritaeniorhynchus specimens belong to JEV GIb and are in the same evolutionary clade according to molecular evolution analyses. JEV GIb was detected simultaneously from specimens of JE cases and mosquito samples collected in nature in this study, suggesting that the JE outbreak that occurred in Ningxia in 2018 was due to infection of JEV GIb.
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Affiliation(s)
- Wenjing Liu
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, People’s Republic of China
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Shihong Fu
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Xuemin Ma
- Ningxia Hui Autonomous Region Center for Disease Control and Prevention, People’s Republic of China
| | - Xiaojing Chen
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, People’s Republic of China
| | - Dan Wu
- National Immunization Programme, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Liwei Zhou
- Ningxia Hui Autonomous Region Center for Disease Control and Prevention, People’s Republic of China
| | - Qikai Yin
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Fan Li
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Ying He
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Wenwen Lei
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Yixing Li
- National Immunization Programme, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Songtao Xu
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Huaqing Wang
- National Immunization Programme, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Zhenhai Wang
- Center for Neurology, General Hospital of Ningxia Medical University, Ningxia, People’s Republic of China
| | - Huanyu Wang
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Hong Yu
- Department of Pathogenic Biology, School of Basic Medicine, Qingdao University, Qingdao, People’s Republic of China
| | - Guodong Liang
- Department of Arbovirus, NHC Key Laboratory of Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, People’s Republic of China
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28
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Hameed M, Liu K, Anwar MN, Wahaab A, Safdar A, Di D, Boruah P, Xu J, Wang X, Li B, Zhu H, Nawaz M, Shao D, Qiu Y, Wei J, Ma Z. The emerged genotype I of Japanese encephalitis virus shows an infectivity similar to genotype III in Culex pipiens mosquitoes from China. PLoS Negl Trop Dis 2019; 13:e0007716. [PMID: 31557156 PMCID: PMC6762057 DOI: 10.1371/journal.pntd.0007716] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 08/16/2019] [Indexed: 12/14/2022] Open
Abstract
Japanese Encephalitis virus (JEV) is a zoonotic flavivirus that represents the most significant etiology of childhood viral neurological infections throughout the Asia. During the last 20 years, JEV genotype dominance has shifted from genotype III (GIII) to genotype I (GI). To date, the exact mechanism of this displacement is still not known. Culex (Cx.) mosquitoes are the most common species in China and play an essential role in maintaining JEV enzootic transmission cycle. In this study, we used Cx. pipiens mosquitoes from China as an in vivo mosquito model to explore if mosquitoes played a potential role in JEV genotype shift. We exposed female Cx. pipiens mosquitoes orally to either GI or GIII JEV strains. Midgut, whole mosquitoes, secondary organs, and salivary glands of JEV-infected mosquitoes were collected at 7 and 14 days of post infection (dpi) and subjected to measure the infection rate, replication kinetics, dissemination rate and transmission potential of the infected JEV strains in Cx. pipiens mosquitoes by 50% tissue culture infective dose assay. We found that Cx. pipiens mosquito was competent vector for both GI and GIII JEV infection, with similar infection rates and growth kinetics. After the establishment of infection, Cx. pipiens mosquitoes disseminated both JEV genotypes to secondary organs at similar rates of dissemination. A few GI-infected mosquito salivary glands (16.2%) were positive for GI virus, whereas GIII virus was undetectable in GIII-infected mosquito salivary glands at 7 dpi. However, 29.4% (5/17) and 36.3% (8/22) were positive for GI- and GIII-infected mosquito salivary glands at 14 dpi, respectively, showing an increase in JEV positive rate. No statistical difference in the transmission rate between GI- and GIII-infected mosquitoes was detected. Our experiment data demonstrated that GI and GIII viruses have similar infectivity in Cx. pipiens mosquitoes, suggesting that Cx. pipiens mosquitoes from China may not play a critical role in JEV genotype shift. Although the current data were obtained solely from Cx. pipiens mosquitoes, it is likely that the conclusion drawn could be extrapolated to the role of mosquitoes in JEV genotype shift.
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Affiliation(s)
- Muddassar Hameed
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Ke Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Muhammad Naveed Anwar
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Abdul Wahaab
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Anum Safdar
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Di Di
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Prerona Boruah
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Jinpeng Xu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Xin Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Beibei Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Huaimin Zhu
- Department of Pathogen biology, Second Military Medical University, Shanghai, PR China
| | - Mohsin Nawaz
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Donghua Shao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Yafeng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Jianchao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Zhiyong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
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Abstract
Japanese encephalitis is a mosquito-borne disease that occurs in Asia and is caused by Japanese encephalitis virus (JEV), a member of the genus Flavivirus. Although many flaviviruses can cause encephalitis, JEV causes particularly severe neurological manifestations. The virus causes loss of more disability-adjusted life years than any other arthropod-borne virus owing to the frequent neurological sequelae of the condition. Despite substantial advances in our understanding of Japanese encephalitis from in vitro studies and animal models, studies of pathogenesis and treatment in humans are lagging behind. Few mechanistic studies have been conducted in humans, and only four clinical trials of therapies for Japanese encephalitis have taken place in the past 10 years despite an estimated incidence of 69,000 cases per year. Previous trials for Japanese encephalitis might have been too small to detect important benefits of potential treatments. Many potential treatment targets exist for Japanese encephalitis, and pathogenesis and virological studies have uncovered mechanisms by which these drugs could work. In this Review, we summarize the epidemiology, clinical features, prevention and treatment of Japanese encephalitis and focus on potential new therapeutic strategies, based on repurposing existing compounds that are already suitable for human use and could be trialled without delay. We use our newly improved understanding of Japanese encephalitis pathogenesis to posit potential treatments and outline some of the many challenges that remain in tackling the disease in humans.
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Fan YC, Liang JJ, Chen JM, Lin JW, Chen YY, Su KH, Lin CC, Tu WC, Chiou MT, Ou SC, Chang GJJ, Lin YL, Chiou SS. NS2B/NS3 mutations enhance the infectivity of genotype I Japanese encephalitis virus in amplifying hosts. PLoS Pathog 2019; 15:e1007992. [PMID: 31381617 PMCID: PMC6695206 DOI: 10.1371/journal.ppat.1007992] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 08/15/2019] [Accepted: 07/20/2019] [Indexed: 12/12/2022] Open
Abstract
Genotype I (GI) virus has replaced genotype III (GIII) virus as the dominant Japanese encephalitis virus (JEV) in the epidemic area of Asia. The mechanism underlying the genotype replacement remains unclear. Therefore, we focused our current study on investigating the roles of mosquito vector and amplifying host(s) in JEV genotype replacement by comparing the replication ability of GI and GIII viruses. GI and GIII viruses had similar infection rates and replicated to similar viral titers after blood meal feedings in Culex tritaeniorhynchus. However, GI virus yielded a higher viral titer in amplifying host-derived cells, especially at an elevated temperature, and produced an earlier and higher viremia in experimentally inoculated pigs, ducklings, and young chickens. Subsequently we identified the amplification advantage of viral genetic determinants from GI viruses by utilizing chimeric and recombinant JEVs (rJEVs). Compared to the recombinant GIII virus (rGIII virus), we observed that both the recombinant GI virus and the chimeric rJEVs encoding GI virus-derived NS1-3 genes supported higher replication ability in amplifying hosts. The replication advantage of the chimeric rJEVs was lost after introduction of a single substitution from a GIII viral mutation (NS2B-L99V, NS3-S78A, or NS3-D177E). In addition, the gain-of-function assay further elucidated that rGIII virus encoding GI virus NS2B-V99L/NS3-A78S/E177E substitutions re-gained the enhanced replication ability. Thus, we conclude that the replication advantage of GI virus in pigs and poultry is the result of three critical NS2B/NS3 substitutions. This may lead to more efficient transmission of GI virus than GIII virus in the amplifying host-mosquito cycle. Flaviviral vertebrate amplifying host(s), invertebrate vector(s), genetics, and environmental factors shape the viral geographical distribution and epidemic disease pattern. Newly emerging dengue virus genotypes, West Nile virus clades, or Zika virus strains exhibited an enhancement in mosquito vector competence. However, hosts and viral determinants responsible for the occurrence of JEV genotype replacement remains unclear. Here, we demonstrated that emerging GI viruses with enhanced transmission potential in amplifying hosts such as pigs and avian species was encoded by three critical GI-specific mutations in NS2B/NS3 proteins. This discovery provides insight into the viral genetic mechanism underlying the GI virus advantage and adaptation in the pig/avian species-mosquito cycle. Our results also emphasize the importance of monitoring viral evolution in amplifying vertebrate hosts to clarify the role of avian species in local transmission of GI virus in JE endemic and epidemic countries.
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Affiliation(s)
- Yi-Chin Fan
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan
- Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan
| | - Jian-Jong Liang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Jo-Mei Chen
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan
| | - Jen-Wei Lin
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan
| | - Yi-Ying Chen
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan
| | - Kuan-Hsuan Su
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Chang-Chi Lin
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Wu-Chun Tu
- Department of Entomology, National Chung Hsing University, Taichung, Taiwan
| | - Ming-Tang Chiou
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan
| | - Shan-Chia Ou
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan
| | - Gwong-Jen J. Chang
- Arboviral Diseases Branch, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America
| | - Yi-Ling Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Shyan-Song Chiou
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taiwan
- * E-mail:
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Wei J, Wang X, Zhang J, Guo S, Pang L, Shi K, Liu K, Shao D, Qiu Y, Liu L, Widén F, Li B, Ma Z. Partial cross-protection between Japanese encephalitis virus genotype I and III in mice. PLoS Negl Trop Dis 2019; 13:e0007601. [PMID: 31374086 PMCID: PMC6693775 DOI: 10.1371/journal.pntd.0007601] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 08/14/2019] [Accepted: 07/03/2019] [Indexed: 02/06/2023] Open
Abstract
Genotype III (GIII) Japanese encephalitis virus (JEV) predominance has gradually been replaced by genotype I (GI) over the last 20 years in many Asian countries. This genotype shift raises concerns about the protective efficacy of Japanese encephalitis (JE) vaccines, as all of the currently licensed JE vaccines are derived from GIII strains. In this study, we conducted vaccination-challenge protection assays to evaluate the cross-protective efficacy of GI- or GIII-derived vaccines against the challenge of a heterologous genotype using a mouse challenge model. Titration of the neutralizing antibodies elicited by SA14-14-2 live-attenuated JE vaccine (SA14-14-2 vaccine), a GIII-derived vaccine, indicated that the titer of neutralizing antibodies specific to heterologous genotype GI stain was significantly lower than that specific to homologous genotype GIII strain in both pigs and mice immunized with the SA14-14-2 vaccine. Vaccination of mice with SA14-14-2 vaccine or a GIII-inactivated vaccine at high and medium doses completely protected vaccinated mice against challenge with the homologous genotype GIII strains, but failed to provide the vaccinated mice complete protection against the challenge of heterologous genotype GI strains. The protection rates against GI strain challenge were 60%–80%, showing that these vaccines were partially protective against GI strain challenge. Additionally, vaccination of mice with a GI-inactivated vaccine conferred 100% protection against the challenge of homologous genotype GI strains, but 50%–90% protection against the challenge of heterologous genotype GIII strains, showing a reduced protective efficacy of a GI-derived vaccine against GIII strain challenge. Overall, these observations demonstrated a partial cross-protection between GI and GIII strains and suggested a potential need for new JE vaccine strategies, including options like a bivalent vaccine, to control both genotype infection. Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes Japanese encephalitis (JE) in humans and reproductive disorders in pigs. JEV is phylogenetically classified into five genotypes. JEV genotype III (GIII) was historically dominant throughout most of Asia, but has been replaced by genotype I (GI) over the last 20 years in many Asian countries. Amino acid variations in JEV envelope protein play major roles in determination of antigenicity. Elicitation of cross-neutralizing antibodies for GI and GIII strains has been reported, showing an antigenic difference between the two genotypes. These amino acid differences in JEV envelope proteins raise a concern about the protective efficacy of JE vaccines against the emerged GI strain infection, because all currently licensed JE vaccines are derived from GIII strains. We evaluated the protective efficacy of JE vaccines against the heterologous genotype strain using a mouse challenge model and found a partial cross-protection between GI- or GIII-derived vaccines against the challenge of the heterologous genotype. This partial cross-protective efficacy suggested a potential need for a new JE vaccine, one solution may be a bivalent vaccine, to control infection with either genotype. However, more comprehensive studies should be conducted to address the partial cross-protective efficacy of JE vaccines against the heterologous genotype strains using JEV natural hosts such as pigs.
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Affiliation(s)
- Jianchao Wei
- Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Xin Wang
- Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Junjie Zhang
- Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Shuang Guo
- Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Linlin Pang
- Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Kun Shi
- Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Ke Liu
- Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Donghua Shao
- Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Yafeng Qiu
- Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
| | - Lihong Liu
- Department of Virology, Immunobiology and Parasitology (VIP), The National Veterinary Institute (SVA), Uppsala, Sweden
| | - Frederik Widén
- Department of Virology, Immunobiology and Parasitology (VIP), The National Veterinary Institute (SVA), Uppsala, Sweden
| | - Beibei Li
- Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
- * E-mail: (BL); (ZM)
| | - Zhiyong Ma
- Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, PR China
- * E-mail: (BL); (ZM)
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Xu Y, Wang Q, Wei B, Huang X, Wen Y, Yan Q, Ma X, Zhao Q, Cao S, Huang Y, Wen X, Han X, Bai Y, Wu R. Enhanced Immune Responses Against Japanese Encephalitis Virus Infection Using Japanese Encephalitis Live-Attenuated Virus Adjuvanted with Montanide GEL 01 ST in Mice. Vector Borne Zoonotic Dis 2019; 19:835-843. [PMID: 31314706 DOI: 10.1089/vbz.2018.2419] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Japanese encephalitis virus (JEV) is one of the major causes of acute encephalitis in human and animal. To prevent JEV infection, an effective live-attenuated vaccine is needed. In the article, JEV attenuated strain, SCYA201201 of GI genotype, which was mixed with 10% concentrate GEL 01 ST adjuvant (Montanide™ GEL 01 ST), was selected for a vaccine candidate and its immunogenicity was evaluated in mice. Our results showed that JEV mixed with GEL 01 ST elicited production of both IgG1 and IgG2a antibodies, and enhanced virus-specific crossprotective intergenotypic response in mice. Proliferation of splenocytes was observed in all immunized groups and a relatively higher proliferation activity was detected in JEV mixed with GEL 01 ST group (p < 0.05). In the JEV + 10% GEL 01 ST vaccinated group, the proportion of CD4+ T cells in spleen was significantly higher than that of control group (p < 0.05), and the yields of interleukin (IL)-2, IL-4, and interferon-γ in the splenocyte supernatant were also significantly higher than that of control group (p < 0.05). Moreover, complete protection was provided after JEV challenge in mice in JEV mixed with GEL 01 ST group, and early immunity was detected in those mice immunized with JEV mixed with GEL 01 ST. These findings confirm that GEL 01 ST can enhance JEV live-attenuated immunogenicity, and JEV +10% GEL 01 ST used as vaccine candidates provide protection against JEV infection in a mouse model, which could be used as potential vaccine candidates in pig.
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Affiliation(s)
- Yixuan Xu
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qiao Wang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Bowen Wei
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xiaobo Huang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yiping Wen
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qigui Yan
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xiaoping Ma
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qin Zhao
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Sanjie Cao
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Sichuan Science-Observation Experimental Station of Veterinary Drugs and Veterinary Diagnostic Technology, Ministry of Agriculture, Chengdu, China
| | - Yong Huang
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xintian Wen
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xinfeng Han
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yu Bai
- Sichuan Science-Observation Experimental Station of Veterinary Drugs and Veterinary Diagnostic Technology, Ministry of Agriculture, Chengdu, China
| | - Rui Wu
- Research Center of Swine Disease, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.,Sichuan Science-Observation Experimental Station of Veterinary Drugs and Veterinary Diagnostic Technology, Ministry of Agriculture, Chengdu, China
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Fang Y, Zhang Y, Zhou ZB, Xia S, Shi WQ, Xue JB, Li YY, Wu JT. New strains of Japanese encephalitis virus circulating in Shanghai, China after a ten-year hiatus in local mosquito surveillance. Parasit Vectors 2019; 12:22. [PMID: 30626442 PMCID: PMC6327439 DOI: 10.1186/s13071-018-3267-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 12/12/2018] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Continuous vector pathogen surveillance is essential for preventing outbreaks of mosquito-borne diseases. Several mosquito species acting as vectors of Japanese encephalitis virus (JEV), dengue virus, Zika virus, malaria parasites and other pathogens are primary mosquito species in Shanghai, China. However, few surveys of human pathogenic arboviruses in mosquitoes in Shanghai have been reported in the last ten years. Therefore, in this study, we evaluated mosquito activity in Shanghai, China during 2016 and tested for the presence of alphaviruses, flaviviruses, orthobunyaviruses and several parasitic pathogens. RESULTS Five pooled samples were JEV-positive [4/255 pools of Culex tritaeniorhynchus and 1/256 pools of Cx. pipiens (s.l.)] based on analysis of the NS5 gene. Alphaviruses, orthobunyaviruses, Plasmodium and filariasis were not found in this study. Phylogenetic and molecular analyses revealed that the JEV strains belonged to genotype I. Moreover, newly detected Shanghai JEV strains were genetically close to previously isolated Shandong strains responsible for transmission during the 2013 Japanese encephalitis (JE) outbreak in Shandong Province, China but were more distantly related to other Shanghai strains detected in the early 2000s. The E proteins of the newly detected Shanghai JEV strains differed from that in the live attenuated vaccine SA14-14-2-derived strain at six amino residues: E130 (Ile→Val), E222 (Ala→Ser), E327 (Ser→Thr), E366 (Arg→Ser/Pro), E393 (Asn→Ser) and E433 (Val→Ile). However, no differences were observed in key amino acid sites related to antigenicity. Minimum JEV infection rates were 1.01 and 0.65 per 1000 Cx. tritaeniorhynchus and Cx. pipiens (s.l.), respectively. CONCLUSIONS Five new Shanghai JEV genotype I strains, detected after a ten-year hiatus in local mosquito surveillance, were genetically close to strains involved in the 2013 Shandong JE outbreak. Because JEV is still circulating, vaccination in children should be extensively and continuously promoted. Moreover, JEV mosquito surveillance programmes should document the genotype variation, intensity and distribution of circulating viruses for use in the development and implementation of disease prevention and control strategies.
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Affiliation(s)
- Yuan Fang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Yi Zhang
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Zheng-Bin Zhou
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Shang Xia
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Wen-Qi Shi
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Jing-Bo Xue
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Yuan-Yuan Li
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
| | - Jia-Tong Wu
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; WHO Collaborating Centre for Tropical Diseases; National Center for International Research on Tropical Diseases, Ministry of Science and Technology; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 20025 People’s Republic of China
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Differential replication efficiencies between Japanese encephalitis virus genotype I and III in avian cultured cells and young domestic ducklings. PLoS Negl Trop Dis 2018; 12:e0007046. [PMID: 30562354 PMCID: PMC6314627 DOI: 10.1371/journal.pntd.0007046] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 01/02/2019] [Accepted: 12/02/2018] [Indexed: 12/28/2022] Open
Abstract
Japanese encephalitis virus (JEV) genotype dominance has shifted to genotype I (GI) from genotype III (GIII) in China as demonstrated by molecular epidemiological surveillance. In this study, we performed a serological survey in JEV-non-vaccinated pigs to confirm JEV genotype shift at the sero-epidemiological level. The average ratio of GI/GIII infection was 1.87, suggesting co-circulation of GI and GIII infections with GI infection being more prevalent in pigs in China. To gain an insight into the reasons for this JEV genotype shift, the replication kinetics of seven recently-isolated JEV isolates including three GI strains and four GIII strains were compared in mosquito C6/36 cells, chicken fibroblast cells (DF-1) and porcine iliac artery endothelial cells (PIEC). We observed that GI strains replicated more efficiently than GIII strains in DF-1 and PIEC cells, particularly in DF-1 cells with titers reaching 22.9–225.3 fold higher than GIII strains. This shows an enhanced replication efficiency of GI viruses in avian cells. To examine this enhanced replication efficiency in vivo, young domestic ducklings were used as the animal model and inoculated with GI and GIII strains at day 2 post-hatching. We observed that GI-inoculated ducklings developed higher viremia titers and displayed a comparatively longer viremic duration than GIII-inoculated ducklings. These results conform to the hypothesis of an enhanced replication efficiency for GI viruses in birds. There are 36 amino acid differences between GI and GIII viruses, some of which may be responsible for the enhanced replication efficiency of GI viruses in birds. Based on these findings, we speculated that the enhanced replication of GI viruses in birds would have resulted in higher exposure and therefore infection in mosquitoes, which could result in an increased transmission efficiency of GI viruses in the birds-mosquitoes-birds enzootic transmission cycle, thereby contributing to JEV genotype shift. Japanese encephalitis virus (JEV) causes encephalitis in humans and reproductive disorder in pigs. The enzootic transmission cycle of JEV is maintained in nature by several species of mosquitoes and vertebrates including birds and pigs. In recent years, JEV genotype I (GI) replaced genotype IIII (GIII) as the dominant genotype in Asian countries. Genotype shift has an impact on disease control, and understanding the reasons for this shift will offer valuable insight into avenues for future disease control. Therefore, we compared the replication efficiencies of GI and GIII viruses in vitro and in vivo. We observed that GI viruses show higher replication titers in avian cells and higher viremia levels in young domestic ducklings than GIII viruses, suggesting an enhanced replication efficiency of GI viruses in birds. Based on these findings, we speculated that the enhanced replication of GI viruses in birds could provide increased mosquito infection, leading to an increase in the birds-mosquitoes-birds transmission cycle, thereby contributing to JEV genotype shift.
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Fan YC, Lin JW, Liao SY, Chen JM, Chen YY, Chiu HC, Shih CC, Chen CM, Chang RY, King CC, Chen WJ, Ko YT, Chang CC, Chiou SS. Virulence of Japanese Encephalitis Virus Genotypes I and III, Taiwan. Emerg Infect Dis 2018; 23:1883-1886. [PMID: 29048288 PMCID: PMC5652437 DOI: 10.3201/eid2311.161443] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The virulence of genotype I (GI) Japanese encephalitis virus (JEV) is under debate. We investigated differences in the virulence of GI and GIII JEV by calculating asymptomatic ratios based on serologic studies during GI- and GIII-JEV endemic periods. The results suggested equal virulence of GI and GIII JEV among humans.
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Full-Genome Characterization and Genetic Evolution of West African Isolates of Bagaza Virus. Viruses 2018; 10:v10040193. [PMID: 29652824 PMCID: PMC5923487 DOI: 10.3390/v10040193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/12/2018] [Accepted: 03/30/2018] [Indexed: 01/26/2023] Open
Abstract
Bagaza virus is a mosquito-borne flavivirus, first isolated in 1966 in Central African Republic. It has currently been identified in mosquito pools collected in the field in West and Central Africa. Emergence in wild birds in Europe and serological evidence in encephalitis patients in India raise questions on its genetic evolution and the diversity of isolates circulating in Africa. To better understand genetic diversity and evolution of Bagaza virus, we describe the full-genome characterization of 11 West African isolates, sampled from 1988 to 2014. Parameters such as genetic distances, N-glycosylation patterns, recombination events, selective pressures, and its codon adaptation to human genes are assessed. Our study is noteworthy for the observation of N-glycosylation and recombination in Bagaza virus and provides insight into its Indian origin from the 13th century. Interestingly, evidence of Bagaza virus codon adaptation to human house-keeping genes is also observed to be higher than those of other flaviviruses well known in human infections. Genetic variations on genome of West African Bagaza virus could play an important role in generating diversity and may promote Bagaza virus adaptation to other vertebrates and become an important threat in human health.
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Hegde NR, Gore MM. Japanese encephalitis vaccines: Immunogenicity, protective efficacy, effectiveness, and impact on the burden of disease. Hum Vaccin Immunother 2017; 13:1-18. [PMID: 28301270 DOI: 10.1080/21645515.2017.1285472] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Japanese encephalitis (JE) is a serious public health concern in most of Asia. The disease is caused by JE virus (JEV), a flavivirus transmitted by Culex mosquitoes. Several vaccines have been developed to control JE in endemic areas as well as to protect travelers and military personnel who visit or are commissioned from non-endemic to endemic areas. The vaccines include inactivated vaccines produced in mouse brain or cell cultures, live attenuated vaccines, and a chimeric vaccine based on the live attenuated yellow fever virus 17D vaccine strain. All the marketed vaccines belong to the JEV genotype III, but have been shown to be efficacious against other genotypes and strains, with varying degrees of cross-neutralization, albeit at levels deemed to be protective. The protective responses have been shown to last three or more years, depending on the type of vaccine and the number of doses. This review presents a brief account of the different JE vaccines, their immunogenicity and protective ability, and the impact of JE vaccines in reducing the burden of disease in endemic countries.
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Affiliation(s)
- Nagendra R Hegde
- a Ella Foundation, Genome Valley , Turkapally, Shameerpet Mandal , Hyderabad , India
| | - Milind M Gore
- b National Institute of Virology, Indian Council of Medical Research , Pune , India
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Mayer SV, Tesh RB, Vasilakis N. The emergence of arthropod-borne viral diseases: A global prospective on dengue, chikungunya and zika fevers. Acta Trop 2017; 166:155-163. [PMID: 27876643 PMCID: PMC5203945 DOI: 10.1016/j.actatropica.2016.11.020] [Citation(s) in RCA: 263] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 10/27/2016] [Accepted: 11/16/2016] [Indexed: 01/02/2023]
Abstract
Arthropod-borne viruses (arboviruses) present a substantial threat to human and animal health worldwide. Arboviruses can cause a variety of clinical presentations that range from mild to life threatening symptoms. Many arboviruses are present in nature through two distinct cycles, the urban and sylvatic cycle that are maintained in complex biological cycles. In this review we briefly discuss the factors driving the emergence of arboviruses, such as the anthropogenic aspects of unrestrained human population growth, economic expansion and globalization. Also the important aspects of viruses and vectors in the occurrence of arboviruses epidemics. The focus of this review will be on dengue, zika and chikungunya viruses, particularly because these viruses are currently causing a negative impact on public health and economic damage around the world.
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Affiliation(s)
- Sandra V Mayer
- Department of Pathology, University of Texas Medical Branch (UTMB), Galveston, TX 77555-0609, USA
| | - Robert B Tesh
- Department of Pathology, University of Texas Medical Branch (UTMB), Galveston, TX 77555-0609, USA; Center for Biodefense and Emerging Infectious Diseases, UTMB, Galveston, USA; Center for Tropical Diseases, UTMB, Galveston, TX 77555-0609, USA; Institute for Human Infections and Immunity, UTMB, Galveston, TX 77555-0610, USA
| | - Nikos Vasilakis
- Department of Pathology, University of Texas Medical Branch (UTMB), Galveston, TX 77555-0609, USA; Center for Biodefense and Emerging Infectious Diseases, UTMB, Galveston, USA; Center for Tropical Diseases, UTMB, Galveston, TX 77555-0609, USA; Institute for Human Infections and Immunity, UTMB, Galveston, TX 77555-0610, USA.
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Differential Infectivities among Different Japanese Encephalitis Virus Genotypes in Culex quinquefasciatus Mosquitoes. PLoS Negl Trop Dis 2016; 10:e0005038. [PMID: 27706157 PMCID: PMC5051684 DOI: 10.1371/journal.pntd.0005038] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 09/13/2016] [Indexed: 12/29/2022] Open
Abstract
During the last 20 years, the epidemiology of Japanese encephalitis virus (JEV) has changed significantly in its endemic regions due to the gradual displacement of the previously dominant genotype III (GIII) with clade b of GI (GI-b). Whilst there is only limited genetic difference distinguishing the two GI clades (GI-a and GI-b), GI-b has shown a significantly wider and more rapid dispersal pattern in several regions in Asia than the GI-a clade, which remains restricted in its geographic distribution since its emergence. Although previously published molecular epidemiological evidence has shown distinct phylodynamic patterns, characterization of the two GI clades has only been limited to in vitro studies. In this study, Culex quinquefasciatus, a known competent JEV mosquito vector species, was orally challenged with three JEV strains each representing GI-a, GI-b, and GIII, respectively. Infection and dissemination were determined based on the detection of infectious viruses in homogenized mosquitoes. Detection of JEV RNA in mosquito saliva at 14 days post infection indicated that Cx. quinquefasciatus can be a competent vector species for both GI and GIII strains. Significantly higher infection rates in mosquitoes exposed to the GI-b and GIII strains than the GI-a strain suggest infectivity in arthropod vectors may lead to the selective advantage of previously and currently dominant genotypes. It could thus play a role in enzootic transmission cycles for the maintenance of JEV if this virus were ever to be introduced into North America. Japanese encephalitis virus (JEV) is a zoonotic flavivirus, which is primarily transmitted by Culex species mosquitoes and a leading cause of pediatric encephalitis in Asia. JEV is also an important public health threat to countries outside the endemic region because collections of Cx. quinquefasciatus from around the world have demonstrated competence for the transmission of JEV and are capable of establishing enzootic transmission cycles between viremic avian and swine species. In the last two decades, the dominantly circulating genotype of JEV in endemic regions has experienced a significant shift (genotype III to Genotype I). It is unclear if the newly dominant circulating G1-b genotype can still be vectored by Cx. quinquefasciatus. In this study, Cx. quinquefasciatus collected from North America was demonstrated to be competent for the transmission of the newly dominant genotype. Different infectivities observed between the endemic strains and non-endemic strain provides the mechanistic knowledge of the selection and emergence of endemic genotypes after continuous viral evolution.
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Sironi M, Forni D, Clerici M, Cagliani R. Nonstructural Proteins Are Preferential Positive Selection Targets in Zika Virus and Related Flaviviruses. PLoS Negl Trop Dis 2016; 10:e0004978. [PMID: 27588756 PMCID: PMC5010288 DOI: 10.1371/journal.pntd.0004978] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 08/14/2016] [Indexed: 11/18/2022] Open
Abstract
The Flavivirus genus comprises several human pathogens such as dengue virus (DENV), Japanese encephalitis virus (JEV), and Zika virus (ZIKV). Although ZIKV usually causes mild symptoms, growing evidence is linking it to congenital birth defects and to increased risk of Guillain-Barré syndrome. ZIKV encodes a polyprotein that is processed to produce three structural and seven nonstructural (NS) proteins. We investigated the evolution of the viral polyprotein in ZIKV and in related flaviviruses (DENV, Spondweni virus, and Kedougou virus). After accounting for saturation issues, alignment uncertainties, and recombination, we found evidence of episodic positive selection on the branch that separates DENV from the other flaviviruses. NS1 emerged as the major selection target, and selected sites were located in immune epitopes or in functionally important protein regions. Three of these sites are located in an NS1 region that interacts with structural proteins and is essential for virion biogenesis. Analysis of the more recent evolutionary history of ZIKV lineages indicated that positive selection acted on NS5 and NS4B, this latter representing the preferential target. All selected sites were located in the N-terminal portion of NS4B, which inhibits interferon response. One of the positively selected sites (26M/I/T/V) in ZIKV also represents a selection target in sylvatic DENV2 isolates, and a nearby residue evolves adaptively in JEV. Two additional positively selected sites are within a protein region that interacts with host (e.g. STING) and viral (i.e. NS1, NS4A) proteins. Notably, mutations in the NS4B region of other flaviviruses modulate neurovirulence and/or neuroinvasiveness. These results suggest that the positively selected sites we identified modulate viral replication and contribute to immune evasion. These sites should be prioritized in future experimental studies. However, analyses herein detected no selective events associated to the spread of the Asian/American ZIKV lineage.
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Affiliation(s)
- Manuela Sironi
- Scientific Institute IRCCS E. MEDEA, Bioinformatics, Bosisio Parini, Italy
| | - Diego Forni
- Scientific Institute IRCCS E. MEDEA, Bioinformatics, Bosisio Parini, Italy
| | - Mario Clerici
- Department of Physiopathology and Transplantation, University of Milan, Milan, Italy
- Don C. Gnocchi Foundation ONLUS, IRCCS, Milan, Italy
| | - Rachele Cagliani
- Scientific Institute IRCCS E. MEDEA, Bioinformatics, Bosisio Parini, Italy
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Althouse BM, Hanley KA. The tortoise or the hare? Impacts of within-host dynamics on transmission success of arthropod-borne viruses. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0299. [PMID: 26150665 DOI: 10.1098/rstb.2014.0299] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Arthropod-borne viruses (arboviruses) are maintained in a cycle of alternating transmission between vertebrate hosts and arthropod vectors. Arboviruses possess RNA genomes capable of rapid diversification and adaptation, and the between-host trade-offs inherent to host alternation impose well-documented constraints on arbovirus evolution. Here, we investigate the less well-studied within-host trade-offs that shape arbovirus replication dynamics and transmission. Arboviruses generally establish lifelong infection in vectors but transient infection of variable magnitude (i.e. peak virus concentration) and duration in vertebrate hosts. In the majority of experimental infections of vertebrate hosts, both the magnitude and duration of arbovirus replication depended upon the dose of virus administered, with increasing dose resulting in greater magnitude but shorter duration of viraemia. This pattern suggests that the vertebrate immune response imposes a trade-off between the height and breadth of the virus replication curve. To investigate the impact of this trade-off on transmission, we used a simple modelling approach to contrast the effect of 'tortoise' (low magnitude, long duration viraemia) and 'hare' (high magnitude, short duration viraemia) arbovirus replication strategies on transmission. This model revealed that, counter to previous theory, arboviruses that adopt a tortoise strategy have higher rates of persistence in both host and vector populations.
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Affiliation(s)
- Benjamin M Althouse
- Santa Fe Institute, Santa Fe, NM 87501, USA Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA Institute for Disease Modeling, Bellevue, WA 98005, USA
| | - Kathryn A Hanley
- Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
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Do LP, Bui TM, Phan NT. Mechanism of Japanese encephalitis virus genotypes replacement based on human, porcine and mosquito-originated cell lines model. ASIAN PAC J TROP MED 2016; 9:333-336. [PMID: 27086150 DOI: 10.1016/j.apjtm.2016.03.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 02/20/2016] [Accepted: 03/01/2016] [Indexed: 10/22/2022] Open
Abstract
OBJECTIVE To examine the multiplication efficiency Japanese encephalitis virus (JEV) genotype I (GI) and genotype III (GIII) of different cell lines which originated from human, porcine, mosquitoes in order to prove mechanism of JEV GI replacement JEV GIII since it emerging in nature recent decades. METHODS The mixture of GI and GIII JEV isolates was inoculated on human rhabdomyosarcoma (RD), pig kidney epithelial (PS) and Aedes albopictus C6/36 clone (C6/36) which originated from human, porcine and mosquitoes, respectively. Plaque assays were performed to calculate virus titer and real-time RT-PCR with GI and GIII specific primer sets to quantify the number of GI and GIII RNA copies. RESULTS The highest virus titer reached at the 3rd day of post infection when GI and GIII mixture was inoculated on RD and PS and that of C6/36 was at the 4th day. JEVs were amplified and maintained by C6/36 cells after 10 passages whereas that by RD and PS only limited within 8 and 6 passages, respectively. GI strain amplified and maintained more efficiently on C6/36 and PS but not RD, whereas GIII strain amplified and maintained more efficiently on RD. CONCLUSIONS There is a correlation between the multiplication efficiency of GI and GIII JEV strains when these two genotype strains co-infected on different cell lines with the predominance of GI strains in C6/36 and PS and the limited detection of GI strains in RD cells proving a possible mechanism of shift JEV genotypes in nature recent decades since GI emerging.
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Affiliation(s)
- Loan Phuong Do
- National Institute of Hygiene and Epidemiology, Hanoi 10000, Viet Nam
| | - Trang Minh Bui
- National Institute of Hygiene and Epidemiology, Hanoi 10000, Viet Nam
| | - Nga Thi Phan
- National Institute of Hygiene and Epidemiology, Hanoi 10000, Viet Nam.
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Pathogenic and Genotypic Characterization of a Japanese Encephalitis Virus Isolate Associated with Reproductive Failure in an Indian Pig Herd. PLoS One 2016; 11:e0147611. [PMID: 26895440 PMCID: PMC4760945 DOI: 10.1371/journal.pone.0147611] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 01/06/2016] [Indexed: 11/19/2022] Open
Abstract
Background India is endemic to Japanese encephalitis virus (JEV) and recurrent outbreaks occur mainly in rice growing areas. Pigs are considered to be the amplifying host for JEV and infection in gestating pigs results in reproductive failure. Most studies conducted on JEV infection in Indian pigs have been serological surveys and very little is known about JEV genotypes circulating in pigs. So the potential risk posed by pigs in JEV transmission and the genetic relationship between viruses circulating in pigs, mosquitoes and humans is poorly understood. Methodology/Principal Findings This study was conducted in pigs with a history of reproductive failure characterized by stillborn piglets with neuropathological lesions. Japanese encephalitis (JE) suspected brain specimens inoculated intracerebrally into mice and Vero cells resulted in successful isolation of JEV/SW/IVRI/395A/2014. Clinicopathological observations in infected mice, demonstration of JEV antigen in brain, and analysis of the envelope protein identified the swine isolate as being neurovirulent. Phylogenetic analysis based on prM and E gene sequences showed that it belonged to genotype III. This swine isolate was closely related to JEV associated with the 2005 outbreak in India and JaoArS982 from Japan. Phylogenetic analysis of JEV strains collected between 1956 and 2014 in India categorized the GIII viruses into different clades blurring their spatial distribution, which has been discernible in the previous century. Conclusions/Significance Isolation of JEV from stillborn piglets and its close genetic relationship with viruses detected at least three decades ago in humans and mosquitoes in Japan suggests that the virus may have been circulating among Indian pigs for several decades. The close similarity between the present swine isolate and those detected in humans affected in the 2005 outbreak in Uttar Pradesh, India, suggests the need for more intensive surveillance of pigs and implementation of suitable strategies to control JE in India.
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Kang BK, Hwang JM, Moon H, Han SY, Kim JM, Yang DK, Park BK, Song D. Comparison of the antigenic relationship between Japanese encephalitis virus genotypes 1 and 3. Clin Exp Vaccine Res 2016; 5:26-30. [PMID: 26866021 PMCID: PMC4742595 DOI: 10.7774/cevr.2016.5.1.26] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 08/10/2015] [Accepted: 09/20/2015] [Indexed: 12/24/2022] Open
Abstract
PURPOSE The Japanese encephalitis virus (JEV) genotype circulating in Korea has changed from G3 to G1. Therefore, the purpose of this study was to compare the antigenic relationship between the two genotypes by using antibody tests. MATERIALS AND METHODS Blood samples from 42 sows and 216 horses were collected, and their seroprevalence was monitored using the hemagglutination inhibition and virus neutralization tests. Antisera against JEV G1 and G3 were isolated and prepared from guinea pigs. The cross-reactivity of these two viruses was then compared using the neutralizing antibody test. RESULTS We found that there was a difference in the seropositive ratios of JEV G1 and G3. However, the difference was dependent on the antibody test used. There was also an observed difference in the antigenicity between the two genotypes, as ascertained using the neutralizing antibody test. CONCLUSION There is an evident difference in JEV antigenicity between the genotypes G1 and G3. Therefore, we propose monitoring of the seroprevalence of JEV, and reevaluating the antigenicity of the current vaccine by using the relevant tests.
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Affiliation(s)
- Bo-Kyu Kang
- Research Unit, Green Cross Veterinary Products, Yongin, Korea
| | - Jeong-Min Hwang
- Research Unit, Green Cross Veterinary Products, Yongin, Korea
| | - Hyoungjoon Moon
- Research Unit, Green Cross Veterinary Products, Yongin, Korea
| | - Sang-Yoon Han
- Research Unit, Green Cross Veterinary Products, Yongin, Korea
| | - Jong-Man Kim
- Research Unit, Green Cross Veterinary Products, Yongin, Korea
| | | | - Bong-Kyun Park
- Department of Veterinary Medicine Virology Laboratory, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Daesub Song
- College of Pharmacy, Korea University, Sejong, Korea
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Qian P, Zhi X, Wang B, Zhang H, Chen H, Li X. Construction and immune efficacy of recombinant pseudorabies virus expressing PrM-E proteins of Japanese encephalitis virus genotype І. Virol J 2015; 12:214. [PMID: 26651827 PMCID: PMC4676090 DOI: 10.1186/s12985-015-0449-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 12/04/2015] [Indexed: 01/24/2023] Open
Abstract
Background Japanese encephalitis (JE) is an arboviral disease with high case fatality rates and neurologic or psychiatric sequelae among survivors in Asia, western Pacific countries and northern Australia. Japanese encephalitis virus (JEV) is the cause of JE and the emergence of genotype І (GI) JEV has displaced genotype III (GIII) as the dominant strains circulating in some Asian regions. The currently available JE vaccines are safe and effective in preventing this disease, but they are developed based on the GIII JEV strains. Methods The recombinant virus PRV TK−/gE−/PrM-E+ which expressed the premembrane (prM) and envelope (E) proteins of JEV SX09S-01 strain (genotype I, GI) was constructed by homologous recombination between the genome of PRV TK−/gE−/LacZ+ digested with EcoRI and plasmid pIE-CAG-PrM-E-BGH. Expression of JEV PrM and E proteins was analyzed by Western blot analysis. Immune efficacy of PRV TK−/gE−/PrM-E+ was further evaluated in mouse model. Results A recombinant pseudorabies virus (PRV TK−/gE−/PrM-E+) was successfully constructed. Mice experiments showed that PRV TK−/gE−/PrM-E+ could induce a high level of ELISA antibodies against PRV and JEV, as well as high titer of PRV neutralizing antibodies. After challenge with 1 × 107 PFU virulent JEV SX09S-01 strain, the time of death was delayed and the survival rate was improved in PRV TK−/gE−/PrM-E+ vaccinated mice. Conclusions PRV TK−/gE−/PrM-E+ is a potential vaccine candidate against PRV and JEV GI infection in the future.
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Affiliation(s)
- Ping Qian
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, P.R. China. .,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R. China. .,Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, P.R China.
| | - Xianwei Zhi
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, P.R. China. .,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R. China.
| | - Bo Wang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, P.R. China. .,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R. China.
| | - Huawei Zhang
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, P.R. China. .,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R. China.
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, P.R. China. .,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R. China. .,Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, P.R China.
| | - Xiangmin Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, P.R. China. .,Laboratory of Animal Virology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, P.R. China. .,Key Laboratory of development of veterinary diagnostic products, Ministry of Agriculture, Wuhan, 430070, P.R China.
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Ting LJ, Lee MS, Lin YL, Cheng MC, Lee F. Invasion of exotic bovine ephemeral fever virus into Taiwan in 2013-2014. Vet Microbiol 2015; 182:15-7. [PMID: 26711023 DOI: 10.1016/j.vetmic.2015.10.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 10/19/2015] [Accepted: 10/26/2015] [Indexed: 10/22/2022]
Abstract
Bovine ephemeral fever virus is a member of the family Rhabdoviridae and bovine ephemeral fever has frequently affected cattle population in Taiwan since 1967. During the outbreaks in 2013 and 2014, exotic bovine ephemeral fever viruses were detected by reverse transcription polymerase chain reaction and nucleotide sequencing. Sequence comparison showed that the exotic viruses shared 99.0-99.4% nucleotide identities (99.4-100.0% amino acid identities) with Chinese viruses and, on the contrary, 96.2-97.2% nucleotide identities (97.8-98.6% amino acid identities) with indigenous Taiwanese viruses. Additionally, our phylogenetic analysis also supported that the newly invaded bovine ephemeral fever viruses were closely related to the Chinese strains. These exotic 2013-2014 viruses have become prevalent and displaced indigenous virus strains since their appearance.
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Affiliation(s)
- Lu-Jen Ting
- Animal Health Research Institute, 376 Chung-Cheng Road, Tamsui District, New Taipei City 25158, Taiwan
| | - Ming-Shiuh Lee
- Animal Health Research Institute, 376 Chung-Cheng Road, Tamsui District, New Taipei City 25158, Taiwan
| | - Yeou-Liang Lin
- Animal Health Research Institute, 376 Chung-Cheng Road, Tamsui District, New Taipei City 25158, Taiwan
| | - Ming-Chu Cheng
- Animal Health Research Institute, 376 Chung-Cheng Road, Tamsui District, New Taipei City 25158, Taiwan
| | - Fan Lee
- Animal Health Research Institute, 376 Chung-Cheng Road, Tamsui District, New Taipei City 25158, Taiwan.
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Han N, Adams J, Fang W, Liu SQ, Rayner S. Investigation of the genotype III to genotype I shift in Japanese encephalitis virus and the impact on human cases. Virol Sin 2015; 30:277-89. [PMID: 26311492 DOI: 10.1007/s12250-015-3621-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/13/2015] [Indexed: 11/28/2022] Open
Abstract
Japanese encephalitis is a mosquito borne disease and is the leading cause of viral encephalitis in the Asia-Pacific area. The causative agent, Japanese encephalitis virus (JEV) can be phylogenetically classified into five genotypes based on nucleotide sequence. In recent years, genotype I (GI) has displaced genotype III (GIII) as the dominant lineage, but the mechanisms behind this displacement event requires elucidation. In an earlier study, we compared host variation over time between the two genotypes and observed that GI appears to have evolved to achieve more efficient infection in hosts in the replication cycle, with the tradeoff of reduced infectivity in secondary hosts such as humans. To further investigate this phenomenon, we collected JEV surveillance data on human cases and, together with sequence data, and generated genotype/case profiles from seven Asia-Pacific countries and regions to characterize the GI/GIII displacement event. We found that, when comprehensive and consistent vaccination and surveillance data was available, and the GIII to GI shift occurred within a well-defined time period, there was a statistically significant drop in JEV human cases. Our findings provide further support for the argument that GI is less effective in infecting humans, who represent a dead end host. However, experimental investigation is necessary to confirm this hypothesis. The study highlights the value of alternative approaches to investigation of epidemics, as well as the importance of effective data collection for disease surveillance and control.
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Affiliation(s)
- Na Han
- State Key Laboratory for Infectious Diseases Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, China
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Tian HY, Bi P, Cazelles B, Zhou S, Huang SQ, Yang J, Pei Y, Wu XX, Fu SH, Tong SL, Wang HY, Xu B. How environmental conditions impact mosquito ecology and Japanese encephalitis: an eco-epidemiological approach. ENVIRONMENT INTERNATIONAL 2015; 79:17-24. [PMID: 25771078 DOI: 10.1016/j.envint.2015.03.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 02/02/2015] [Accepted: 03/01/2015] [Indexed: 06/04/2023]
Abstract
Japanese encephalitis (JE) is one of the major vector-borne diseases in Southeast Asia and the Western Pacific region, posing a threat to human health. In rural and suburban areas, traditional rice farming and intensive pig breeding provide an ideal environment for both mosquito development and the transmission of JEV among human beings. Combining surveillance data for mosquito vectors, human JE cases, and environmental conditions in Changsha, China, 2004-2009, generalized threshold models were constructed to project the mosquito and JE dynamics. Temperature and rainfall were found to be closely associated with mosquito density at 1, and 4month lag, respectively. The two thresholds, maximum temperature of 22-23°C for mosquito development and minimum temperature of 25-26°C for JEV transmission, play key roles in the ecology of JEV. The model predicts that, in the upper regime, a 1g/m(3) increase in absolute humidity would on average increase human cases by 68-84%. A shift in mosquito species composition in 2007 was observed, and possibly caused by a drought. Effective predictive models could be used in risk management to provide early warnings for potential JE transmission.
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Affiliation(s)
- Huai-Yu Tian
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, People's Republic of China
| | - Peng Bi
- Discipline of Public Health, University of Adelaide, Adelaide, Australia
| | - Bernard Cazelles
- UMMISCO, UMI 209 IRD-UPMC, 93142 Bondy, France; Eco-Evolutionary Mathematic, IBENS UMR 8197, ENS, 75230 Paris Cedex 05, France
| | - Sen Zhou
- Ministry of Education Key Laboratory for Earth System Modelling, Center for Earth System Science, Tsinghua University, Beijing, People's Republic of China
| | - Shan-Qian Huang
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, People's Republic of China
| | - Jing Yang
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, People's Republic of China
| | - Yao Pei
- Ministry of Education Key Laboratory for Earth System Modelling, Center for Earth System Science, Tsinghua University, Beijing, People's Republic of China
| | - Xiao-Xu Wu
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, People's Republic of China
| | - Shi-Hong Fu
- State Key Laboratory for Infectious Disease Prevention and Control (SKLID), Department of Viral Encephalitis, Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China
| | - Shi-Lu Tong
- School of Public Health and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland 4059, Australia
| | - Huan-Yu Wang
- State Key Laboratory for Infectious Disease Prevention and Control (SKLID), Department of Viral Encephalitis, Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, People's Republic of China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, People's Republic of China.
| | - Bing Xu
- State Key Laboratory of Remote Sensing Science, College of Global Change and Earth System Science, Beijing Normal University, Beijing, People's Republic of China; Ministry of Education Key Laboratory for Earth System Modelling, Center for Earth System Science, Tsinghua University, Beijing, People's Republic of China; Department of Geography, University of Utah, Salt Lake City, UT 84112, USA.
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Ye Q, Xu YP, Zhang Y, Li XF, Wang HJ, Liu ZY, Li SH, Liu L, Zhao H, Nian QG, Deng YQ, Qin ED, Qin CF. Genotype-specific neutralization determinants in envelope protein: implications for the improvement of Japanese encephalitis vaccine. J Gen Virol 2015; 96:2165-2175. [PMID: 25908779 DOI: 10.1099/vir.0.000160] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Japanese encephalitis remains the leading cause of viral encephalitis in children in Asia and is expanding its geographical range to larger areas in Asia and Australasia. Five genotypes of Japanese encephalitis virus (JEV) co-circulate in the geographically affected areas. In particular, the emergence of genotype I (GI) JEV has displaced genotype III (GIII) as the dominant circulating genotype in many Asian regions. However, all approved vaccine products are derived from GIII strains. In the present study, bioinformatic analysis revealed that GI and GIII JEV strains shared two distinct amino acid residues within the envelope (E) protein (E222 and E327). By using reverse genetics approaches, A222S and S327T mutations were demonstrated to decrease live-attenuated vaccine (LAV) SA14-14-2-induced neutralizing antibodies in humans, without altering viral replication. A222S or S327T mutations were then rationally engineered into the infectious clone of SA14-14-2, and the resulting mutant strains retained the same genetic stability and attenuation characteristics as the parent strain. More importantly, immunization of mice with LAV-A222S or LAV-S327T elicited increased neutralizing antibodies against GI strains. Together, these results demonstrated that E222 and E327 are potential genotype-related neutralization determinants and are critical in determining the protective efficacy of live Japanese encephalitis vaccine SA14-14-2 against circulating GI strains. Our findings will aid in the rational design of the next generation of Japanese encephalitis LAVs capable of providing broad protection against all JEV strains belonging to different genotypes.
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Affiliation(s)
- Qing Ye
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Yan-Peng Xu
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Yu Zhang
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Xiao-Feng Li
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.,State Key Laboratory of Pathogen and Biosecurity, Beijing 100071, PR China
| | - Hong-Jiang Wang
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Zhong-Yu Liu
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Shi-Hua Li
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Long Liu
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.,Graduate School, Anhui Medical University, Hefei 230032, PR China
| | - Hui Zhao
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.,State Key Laboratory of Pathogen and Biosecurity, Beijing 100071, PR China
| | - Qing-Gong Nian
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Yong-Qiang Deng
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - E-De Qin
- Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Cheng-Feng Qin
- Graduate School, Anhui Medical University, Hefei 230032, PR China.,Department of Virology, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.,State Key Laboratory of Pathogen and Biosecurity, Beijing 100071, PR China
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50
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Do LP, Bui TM, Hasebe F, Morita K, Phan NT. Molecular epidemiology of Japanese encephalitis in northern Vietnam, 1964-2011: genotype replacement. Virol J 2015; 12:51. [PMID: 25889499 PMCID: PMC4417254 DOI: 10.1186/s12985-015-0278-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 03/11/2015] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Japanese encephalitis virus (JEV) is an arthropod-borne virus causing serious public health issues in Asia. JEV consists of five genotypes and recent studies have shown the emergence of JEV genotype I (GI) and its replacement of genotype III (GIII). Using an archival JEV collection, we investigated the molecular evolution of JEV in Vietnam over the last 48 years (1964-2012) in humans, mosquitoes, and pigs, within the global context. METHODS The nine JEV isolates from humans, pigs, and mosquitoes sequenced in this study and 29 sequences available in GenBank were used to analyze the envelope (E) protein of the Vietnamese JEVs. A collection of 225 cerebrospinal fluid specimens from patients with suspected Japanese encephalitis (JE) was also tested and genotyped with real-time RT-PCR. RESULTS The 38 E genes identified with sequencing and nine Vietnamese JEV strains genotyped with real-time RT-PCR, belonging to two lineages, evolved in accordance with those in the rest of the world. The first GIII strain was detected in humans in Vietnam in 1964, and in mosquitoes in 1979, whereas GI strains were first detected in humans and mosquitoes in 1990 and 1994, respectively. After 2004, GI was the only genotype detected in Vietnam, demonstrating that the GIIII strains had been displaced by GI strains. Five haplotypes were identified in the Vietnamese JEVs, with SKSS predominant. The S123N and S123R substitutions in the E protein were already present in the Vietnamese JEVs. CONCLUSION This study describes the long evolutionary history of JEV in Vietnam over 34 years, which correlates well with the global evolution of JEV. The Vietnamese GIII strains have been replaced by GI strains in mosquitoes, pigs, and humans. The predominant haplotypes of the Vietnamese strains support this genotype displacement in Vietnam. Further surveillance is required to confirm the disappearance of the GIII strains in nature and the emergence of new pathogens causing encephalitis in Vietnam, after the long-term use of JEV vaccines in that country.
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Affiliation(s)
- Loan Phuong Do
- National Institute of Hygiene and Epidemiology, Hanoi, 10000, Vietnam.
| | - Trang Minh Bui
- National Institute of Hygiene and Epidemiology, Hanoi, 10000, Vietnam.
| | - Futoshi Hasebe
- Institute of Tropical Medicine, Nagasaki University, Nagasaki, 852-8523, Japan.
| | - Kouichi Morita
- Institute of Tropical Medicine, Nagasaki University, Nagasaki, 852-8523, Japan.
| | - Nga Thi Phan
- National Institute of Hygiene and Epidemiology, Hanoi, 10000, Vietnam.
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