West Nile virus (WNV) is transmitted to humans and animals by a mosquito and enters the central nervous system, leading to lethal encephalitis. Reporter viruses expressing fluorescent proteins enable detection of infected cells in vitro and in vivo, facilitating evaluation of the dynamics of viral infection, and the development of diagnostic or therapeutic methods. In this study, we developed a method for production of a recombinant replication-competent WNV expressing mCherry fluorescent protein. The expression of mCherry was observed in viral antigen-positive cells in vitro and in vivo, but the growth of the reporter WNV was reduced as compared to the parental WNV. The expression of mCherry was stable during 5 passages in reporter WNV-infected culture cells. Neurological symptoms were observed in mice inoculated intracranially with the reporter WNV. The reporter WNV expressing mCherry will facilitate research into WNV replication in mouse brains.
- MeSH
- lidé MeSH
- myši MeSH
- rekombinantní proteiny genetika MeSH
- virus západního Nilu * genetika MeSH
- západonilská horečka * veterinární MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BackgroundDespite the known circulation of West Nile virus (WNV) and Usutu virus (USUV) in Slovakia, no formal entomological surveillance programme has been established there thus far.AimTo conduct contemporaneous surveillance of WNV and USUV in different areas of Slovakia and to assess the geographical spread of these viruses through mosquito vectors. The first autochthonous human WNV infection in the country is also described.MethodsMosquitoes were trapped in four Slovak territorial units in 2018 and 2019. Species were characterised morphologically and mosquito pools screened for WNV and USUV by real-time reverse-transcription PCRs. In pools with any of the two viruses detected, presence of pipiens complex group mosquitoes was verified using molecular approaches.ResultsAltogether, 421 pools containing in total 4,508 mosquitoes were screened. Three pools tested positive for WNV and 16 for USUV. USUV was more prevalent than WNV, with a broader spectrum of vectors and was detected over a longer period (June-October vs August for WNV). The main vectors of both viruses were Culex pipiens sensu lato. Importantly, WNV and USUV were identified in a highly urbanised area of Bratislava city, Slovakias' capital city. Moreover, in early September 2019, a patient, who had been bitten by mosquitoes in south-western Slovakia and who had not travelled abroad, was laboratory-confirmed with WNV infection.ConclusionThe entomological survey results and case report increase current understanding of the WNV and USUV situation in Slovakia. They underline the importance of vector surveillance to assess public health risks posed by these viruses.
- MeSH
- Culex * MeSH
- Culicidae * MeSH
- Flavivirus * genetika MeSH
- lidé MeSH
- virus západního Nilu * genetika MeSH
- západonilská horečka * diagnóza epidemiologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- Geografické názvy
- Slovenská republika MeSH
West Nile virus lineage 2 (WNV-2) was detected in the brain of 17 goshawks (Accipiter gentilis) that succumbed to neuroinvasive disease in the Czech Republic during 2018: twelve birds were captive and five wild. Furthermore, two wild sparrowhawks (Accipiter nisus) and three other captive birds of prey (golden eagle Aquila chrysaetos, hybrid saker falcon Falco cherrug × F. rusticolus and Harris's hawk Parabuteo unicinctus) also died due to WNV encephalitis. The 2018 outbreak in Czech raptors clearly reflects a new epidemiological situation and indicates an increasing risk of both raptor and human infection with WNV-2 in the country.
- MeSH
- epidemický výskyt choroby * MeSH
- některé rody čeledi Accipitridae mikrobiologie MeSH
- nemoci ptáků epidemiologie virologie MeSH
- veřejné zdravotnictví MeSH
- virus západního Nilu genetika MeSH
- západonilská horečka epidemiologie veterinární MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Monitoring West Nile virus (WNV) and Usutu virus (USUV) activity now has the highest priority among mosquito-borne pathogenic viruses circulating in the European Union. This study documents a first time detection and the co-circulation of WNV lineage-2 (with the minimal prevalence of 0.46%) and USUV clade Europe 2 (with the minimal prevalence of 0.25%) in mosquitoes from the same habitat of south-western Slovakia and underlines necessity to perform rigorous surveillance in birds, mosquitoes, horses and humans in that country.
- MeSH
- Culex virologie MeSH
- Culicidae virologie MeSH
- ekosystém MeSH
- Flavivirus genetika izolace a purifikace MeSH
- fylogeneze MeSH
- infekce viry z rodu Flavivirus epidemiologie veterinární MeSH
- komáří přenašeči virologie MeSH
- koně virologie MeSH
- lidé MeSH
- prevalence MeSH
- ptáci virologie MeSH
- veřejné zdravotnictví MeSH
- virus západního Nilu genetika izolace a purifikace MeSH
- západonilská horečka epidemiologie veterinární MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Slovenská republika MeSH
West Nile virus (WNV) is a medically important emerging arbovirus causing serious neuroinfections in humans and against which no approved antiviral therapy is currently available. In this study, we demonstrate that 2'-C-methyl- or 4'-azido-modified nucleosides are highly effective inhibitors of WNV replication, showing nanomolar or low micromolar anti-WNV activity and negligible cytotoxicity in cell culture. One representative of C2'-methylated nucleosides, 7-deaza-2'-C-methyladenosine, significantly protected WNV-infected mice from disease progression and mortality. Twice daily treatment at 25 mg/kg starting at the time of infection resulted in 100% survival of the mice. This compound was highly effective, even if the treatment was initiated 3 days postinfection, at the time of a peak of viremia, which resulted in a 90% survival rate. However, the antiviral effect of 7-deaza-2'-C-methyladenosine was absent or negligible when the treatment was started 8 days postinfection (i.e., at the time of extensive brain infection). The 4'-azido moiety appears to be another important determinant for highly efficient inhibition of WNV replication in vitro However, the strong anti-WNV effect of 4'-azidocytidine and 4'-azido-aracytidine was cell type dependent and observed predominantly in porcine kidney stable (PS) cells. The effect was much less pronounced in Vero cells. Our results indicate that 2'-C-methylated or 4'-azidated nucleosides merit further investigation as potential therapeutic agents for treating WNV infections as well as infections caused by other medically important flaviviruses.
- MeSH
- antivirové látky terapeutické užití MeSH
- buněčné linie MeSH
- Cercopithecus aethiops MeSH
- modely nemocí na zvířatech MeSH
- myši inbrední BALB C MeSH
- myši MeSH
- prasata MeSH
- progrese nemoci MeSH
- replikace viru účinky léků MeSH
- RNA-dependentní RNA-polymerasa antagonisté a inhibitory MeSH
- tubercidin analogy a deriváty terapeutické užití MeSH
- Vero buňky MeSH
- viremie farmakoterapie MeSH
- virus západního Nilu účinky léků genetika MeSH
- západonilská horečka farmakoterapie patologie virologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
In 2017, we isolated and identified West Nile virus (WNV) lineage 2 from two dead captive goshawks (Accipiter gentilis), for the first time in the Czech Republic. Goshawk might serve as an early indicator species for the ongoing WNV emergence in several European countries.
Arthropod-borne flaviviruses are human pathogens of global medical importance, against which no effective small molecule-based antiviral therapy has currently been reported. Arbidol (umifenovir) is a broad-spectrum antiviral compound approved in Russia and China for prophylaxis and treatment of influenza. This compound shows activities against numerous DNA and RNA viruses. The mode of action is based predominantly on impairment of critical steps in virus-cell interactions. Here we demonstrate that arbidol possesses micromolar-level anti-viral effects (EC50 values ranging from 10.57 ± 0.74 to 19.16 ± 0.29 μM) in Vero cells infected with Zika virus, West Nile virus, and tick-borne encephalitis virus, three medically important representatives of the arthropod-borne flaviviruses. Interestingly, no antiviral effects of arbidol are observed in virus infected porcine stable kidney cells (PS), human neuroblastoma cells (UKF-NB-4), and human hepatoma cells (Huh-7 cells) indicating that the antiviral effect of arbidol is strongly cell-type dependent. Arbidol shows increasing cytotoxicity when tested in various cell lines, in the order: Huh-7 < HBCA < PS < UKF-NB-4 < Vero with CC50 values ranging from 18.69 ± 0.1 to 89.72 ± 0.19 μM. Antiviral activities and acceptable cytotoxicity profiles suggest that arbidol could be a promising candidate for further investigation as a potential therapeutic agent in selective treatment of flaviviral infections.
- MeSH
- antivirové látky farmakologie toxicita MeSH
- buněčné linie MeSH
- Cercopithecus aethiops MeSH
- členovci - vektory virologie MeSH
- Flavivirus účinky léků genetika MeSH
- indoly farmakologie toxicita MeSH
- infekce viry z rodu Flavivirus virologie MeSH
- inhibiční koncentrace 50 MeSH
- lidé MeSH
- proteiny virového obalu genetika MeSH
- regulace exprese virových genů účinky léků MeSH
- Vero buňky MeSH
- viabilita buněk účinky léků MeSH
- virus západního Nilu účinky léků genetika MeSH
- virus zika účinky léků genetika MeSH
- viry klíšťové encefalitidy účinky léků genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: West Nile virus (WNV) is currently the most important mosquito-borne pathogen spreading in Europe. Data on overwintering of WNV in mosquitoes are crucial for understanding WNV circulation in Europe; nonetheless, such data were not available so far. RESULTS: A total of 28,287 hibernating mosquitoes [27,872 Culex pipiens, 73 Anopheles maculipennis (sensu lato), and 342 Culiseta annulata], caught in February or March between 2011 and 2017 in a WNV-endemic region of South Moravia, Czech Republic, were screened for the presence of WNV RNA. No WNV positive pools were found from 2011 to 2016, while lineage 2 WNV RNA was detected in three pools of Culex pipens mosquitoes collected in 2017 at two study sites. CONCLUSIONS: To the best of our knowledge, this is the first record of WNV RNA in overwintering mosquitoes in Europe. The data support the hypothesis of WNV persistence in mosquitoes throughout the winter season in Europe.
- MeSH
- Culicidae virologie MeSH
- hmyz - vektory virologie MeSH
- lidé MeSH
- roční období MeSH
- virus západního Nilu genetika izolace a purifikace fyziologie MeSH
- západonilská horečka epidemiologie přenos virologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Evropa epidemiologie MeSH
BACKGROUND: Mosquito-borne flaviviruses are a major public health threat in many countries worldwide. In Central Europe, West Nile virus (WNV) and Usutu virus (USUV), both belonging to the Japanese encephalitis virus group (Flaviviridae) have emerged in the last decennium. Surveillance of mosquito vectors for arboviruses is a sensitive tool to evaluate virus circulation and consequently to estimate the public health risk. METHODS: Mosquitoes (Culicidae) were collected at South-Moravian (Czech Republic) fishponds between 2010 and 2014. A total of 61,770 female Culex modestus Ficalbi mosquitoes, pooled to 1,243 samples, were examined for flaviviruses by RT-PCR. RESULTS: One pool proved positive for USUV RNA. Phylogenetic analysis demonstrated that this Czech USUV strain is closely related to Austrian and other Central European strains of the virus. In addition, nine strains of WNV lineage 2 were detected in Cx. modestus collected in the same reed bed ecosystem. CONCLUSIONS: This is the first detection of USUV in Cx. modestus. The results indicate that USUV and WNV may co-circulate in a sylvatic cycle in the same habitat, characterised by the presence of water birds and Cx. modestus mosquitoes, serving as hosts and vectors, respectively, for both viruses.
- MeSH
- arboviry genetika izolace a purifikace MeSH
- Culex virologie MeSH
- Culicidae virologie MeSH
- ekosystém MeSH
- encefalitida přenášená členovci epidemiologie MeSH
- epidemiologické monitorování MeSH
- fylogeneze MeSH
- hmyz - vektory virologie MeSH
- infekce viry z rodu Flavivirus epidemiologie MeSH
- lidé MeSH
- molekulární sekvence - údaje MeSH
- ptáci MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- virus západního Nilu genetika izolace a purifikace MeSH
- viry japonské encefalitidy genetika izolace a purifikace MeSH
- západonilská horečka epidemiologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa epidemiologie MeSH
The detection of West Nile virus (WNV) nucleic acid in a blood donation from Vienna, Austria, as well as in Culex pipiens pupae and egg rafts, sampled close to the donor's residence, is reported. Complete genomic sequences of the human- and mosquito-derived viruses were established, genetically compared and phylogenetically analyzed. The viruses were not identical, but closely related to each other and to recent Czech and Italian isolates, indicating co-circulation of related WNV strains within a confined geographic area. The detection of WNV in a blood donation originating from an area with low WNV prevalence in humans (only three serologically diagnosed cases between 2008 and 2014) is surprising and emphasizes the importance of WNV nucleic acid testing of blood donations even in such areas, along with active mosquito surveillance programs.
- MeSH
- Culex virologie MeSH
- dárci krve * MeSH
- dospělí MeSH
- epidemiologické monitorování MeSH
- fylogeneze MeSH
- hmyz - vektory virologie MeSH
- lidé MeSH
- molekulární typizace MeSH
- myši inbrední ICR MeSH
- myši MeSH
- polymerázová řetězová reakce MeSH
- polyproteiny genetika MeSH
- virové proteiny genetika MeSH
- virus západního Nilu klasifikace genetika izolace a purifikace MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- západonilská horečka diagnóza přenos virologie MeSH
- zvířata MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Rakousko MeSH
