scholarly journals The emerged genotype I of Japanese encephalitis virus shows an infectivity similar to genotype III in Culex pipiens mosquitoes from China

2019 ◽  
Vol 13 (9) ◽  
pp. e0007716 ◽  
Author(s):  
Muddassar Hameed ◽  
Ke Liu ◽  
Muhammad Naveed Anwar ◽  
Abdul Wahaab ◽  
Anum Safdar ◽  
...  
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Culex Pipiens ◽  
Encephalitis Virus ◽  
Genotype I ◽  
Genotype Iii

scholarly journals Potential Role of Birds in Japanese Encephalitis Virus Zoonotic Transmission and Genotype Shift

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 357
Author(s):  
Muddassar Hameed ◽  
Abdul Wahaab ◽  
Mohsin Nawaz ◽  
Sawar Khan ◽  
Jawad Nazir ◽  
...  
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Encephalitis Virus ◽  
Zoonotic Transmission ◽  
In Vivo Studies ◽  
Genotype I ◽  
Genotype Iii

Japanese encephalitis (JE) is a vaccine-preventable disease caused by the Japanese encephalitis virus (JEV), which is primarily prevalent in Asia. JEV is a Flavivirus, classified into a single serotype with five genetically distinct genotypes (I, II, III, IV, and V). JEV genotype III (GIII) had been the most dominant strain and caused numerous outbreaks in the JEV endemic countries until 1990. However, recent data shows the emergence of JEV genotype I (GI) as a dominant genotype and it is gradually displacing GIII. The exact mechanism of this genotype displacement is still unclear. The virus can replicate in mosquito vectors and vertebrate hosts to maintain its zoonotic life cycle; pigs and aquatic wading birds act as an amplifying/reservoir hosts, and the humans and equines are dead-end hosts. The important role of pigs as an amplifying host for the JEV is well known. However, the influence of other domestic animals, especially birds, that live in high abundance and close proximity to the human is not well studied. Here, we strive to briefly highlight the role of birds in the JEV zoonotic transmission, discovery of birds as a natural reservoirs and amplifying host for JEV, species of birds susceptible to the JEV infection, and the proposed effect of JEV on the poultry industry in the future, a perspective that has been neglected for a long time. We also discuss the recent in vitro and in vivo studies that show that the newly emerged GI viruses replicated more efficiently in bird-derived cells and ducklings/chicks than GIII, and an important role of birds in the JEV genotype shift from GIII to GI.

scholarly journals Temperate conditions restrict Japanese encephalitis virus infection to the mid-gut and prevents systemic dissemination in Culex pipiens mosquitoes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Arran J. Folly ◽  
Daniel Dorey-Robinson ◽  
Luis M. Hernández-Triana ◽  
Stuart Ackroyd ◽  
Beatriz Vidana ◽  
...  
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Culex Pipiens ◽  
Vector Competence ◽  
Critical Factor ◽  
Encephalitis Virus ◽  
Infected Mosquito ◽  
Japanese Encephalitis Virus Infection ◽  
Genotype Iii ◽  
Posterior Midgut

AbstractJapanese encephalitis virus (JEV), a mosquito-borne flavivirus, is the main cause of viral encephalitis in Asia. However, with changing climate JEV has the potential to emerge in novel temperate regions. Here, we have assessed the vector competence of the temperate mosquito Culex pipiens f. pipiens to vector JEV genotype III at temperatures representative of those experienced, or predicted in the future during the summer months, in the United Kingdom. Our results show that Cx. pipiens is susceptible to JEV infection at both temperatures. In addition, at 25 °C, JEV disseminated from the midgut and was recovered in saliva samples, indicating the potential for transmission. At a lower temperature, 20 °C, following an incubation period of fourteen days, there were reduced levels of JEV dissemination and virus was not detected in saliva samples. The virus present in the bodies of these mosquitoes was restricted to the posterior midgut as determined by microscopy and viable virus was successfully recovered. Apart from the influence on virus dissemination, mosquito mortality was significantly increased at the higher temperature. Overall, our results suggest that temperature is a critical factor for JEV vector competence and infected-mosquito survival. This may in turn influence the vectorial capacity of Cx. pipiens to vector JEV genotype III in temperate areas.

Molecular phylogenetic and evolutionary analysis of Japanese encephalitis virus in China

2011 ◽  
Vol 140 (9) ◽  
pp. 1637-1643 ◽  
Author(s):  
S. P. CHEN
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Envelope Protein ◽  
Purifying Selection ◽  
Encephalitis Virus ◽  
Evolutionary Analysis ◽  
Genotype I ◽  
Genotype Iii ◽  
Molecular Phylogenetic ◽  
Low Prevalence

SUMMARYWe elucidated the molecular epidemiology and evolution of Japanese encephalitis virus (JEV) strains isolated from 1949 to 2009 in China in this study. Three genotypes (I, III, V) were confirmed to be co-circulating in China in both high- and low-prevalence areas. Genotype III consisted of two clades (mainland clade and Taiwan clade). Compared to the mainland clade, genotype I and the Taiwan clade were newly introduced and evolved more rapidly. We also demonstrated that JEV strains in China, especially those in the mainland clade, were not only under purifying selection, but also probably under positive selection (aa 227 and 408 in the envelope protein).

scholarly journals Emergence of Genotype I of Japanese Encephalitis Virus as the Dominant Genotype in Asia

2011 ◽  
Vol 85 (19) ◽  
pp. 9847-9853 ◽  
Author(s):  
X.-L. Pan ◽  
H. Liu ◽  
H.-Y. Wang ◽  
S.-H. Fu ◽  
H.-Z. Liu ◽  
...  
Keyword(s):  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Encephalitis Virus ◽  
Genotype I ◽  
Dominant Genotype

scholarly journals Phenotypic and Genotypic Comparison of a Live-Attenuated Genotype I Japanese Encephalitis Virus SD12-F120 Strain with Its Virulent Parental SD12 Strain

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 552 ◽  
Author(s):  
Muhammad Naveed Anwar ◽  
Xin Wang ◽  
Muddassar Hameed ◽  
Abdul Wahaab ◽  
Chenxi Li ◽  
...  
Keyword(s):  
Amino Acid ◽  
Japanese Encephalitis Virus ◽  
Japanese Encephalitis ◽  
Clinical Symptoms ◽  
Encephalitis Virus ◽  
Amino Acid Substitutions ◽  
Genotype I ◽  
Genetic Changes ◽  
Genotypic Characteristics ◽  
Insight Into

The phenotypic and genotypic characteristics of a live-attenuated genotype I (GI) strain (SD12-F120) of Japanese encephalitis virus (JEV) were compared with its virulent parental SD12 strain to gain an insight into the genetic changes acquired during the attenuation process. SD12-F120 formed smaller plaque on BHK-21 cells and showed reduced replication in mouse brains compared with SD12. Mice inoculated with SD12-F120 via either intraperitoneal or intracerebral route showed no clinical symptoms, indicating a highly attenuated phenotype in terms of both neuroinvasiveness and neurovirulence. SD12-F120 harbored 29 nucleotide variations compared with SD12, of which 20 were considered silent nucleotide mutations, while nine resulted in eight amino acid substitutions. Comparison of the amino acid variations of SD12-F120 vs. SD12 pair with those from other four isogenic pairs of the attenuated and their virulent parental strains revealed that the variations at E138 and E176 positions of E protein were identified in four and three pairs, respectively, while the remaining amino acid variations were almost unique to their respective strain pairs. These observations suggest that the genetic changes acquired during the attenuation process were likely to be strain-specific and that the mechanisms associated with JEV attenuation/virulence are complicated.

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