Working with #Zika and #Usutu #Viruses in #Vitro (BioRxIV, abstract)

[Source: BioRxIV, full page: (LINK). Abstract, edited.]

New Results

Working with Zika and Usutu Viruses in Vitro [      ]

Kelli Barr, Benjamin Anderson, Maureen Long




Usutu and Zika viruses are emerging arboviruses of significant medical and veterinary importance. These viruses have not been studied as well as other medically important arboviruses such as West Nile, dengue, or chikungunya viruses. As such, information regarding the behavior of Zika and Usutu viruses in the laboratory is dated. Usutu virus re-emerged in Austria in 2001 and has since spread throughout the European and Asian continents causing significant mortality among birds. Zika virus has recently appeared in the Americas and has exhibited unique characteristics of pathogenesis, including birth defects, and transmission. Information about the characteristics of Usutu and Zika viruses are needed to better understand the transmission, dispersal, and adaptation of these viruses in new environments. Since their initial characterization in the middle of last century, technologies and reagents have been developed that could enhance our abilities to study these pathogens. Currently, standard laboratory methods for these viruses are limited to 2-3 cell lines and many assays take several days to generate meaningful data. The goal of this study was to characterize these viruses in cell culture to provide some basic parameters to further their study. Cell lines from 17 species were permissive to both Zika and Usutu viruses. These viruses were able to replicate to significant titers in most of the cell lines tested. Moreover, cytopathic effects were observed in 8 of the cell lines tested. The data show that, unlike other flaviviruses, neither Zika nor Usutu viruses require an acidic environment to fuse with a host cell. This may provide a tool to help characterize events or components in the flavivirus fusion process. These data indicate that a variety of cell lines can be used to study Zika and Usutu viruses and may provide an updated foundation for the study of host-pathogen interactions, model development, and the development of therapeutics.

Copyright: The copyright holder for this preprint is the author/funder. All rights reserved. No reuse allowed without permission.

Keywords: Research; Abstracts; Zika Virus; Usutu Virus.


#Detection of #WNV and #Usutu Viruses in #Italian Free Areas: #Entomological #Surveillance in #Piemonte and #Liguria Regions, 2014 (Vector Borne Zoo Dis., abstract)

[Source: Vector Borne and Zoonotic Diseases, full page: (LINK). Abstract, edited.]

Vector-Borne and Zoonotic Diseases

Detection of West Nile and Usutu Viruses in Italian Free Areas: Entomological Surveillance in Piemonte and Liguria Regions, 2014  [      ]

To cite this article: Pautasso Alessandra, Radaelli Maria Cristina, Ballardini Marco, Francese Danila Raffaella, Verna Federica, Modesto Paola, Grattarola Carla, Desiato Rosanna, Bertolini Silvia, Vitale Nicoletta, Ferrari Angelo, Rossini Irene, Accorsi Annalisa, Mosca Andrea, Monaco Federica, Savini Giovanni, Prearo Marino, Mignone Walter, Chiavacci Laura, and Casalone Cristina. Vector-Borne and Zoonotic Diseases. February 2016, ahead of print. doi:10.1089/vbz.2015.1851.

Online Ahead of Print: February 10, 2016



West Nile virus and Usutu virus have established in different parts of Italy over the past 10 years. Piemonte and Liguria Regions (Northwestern Italy) are known to be nonendemic areas, despite the presence of competent vectors and environmental conditions conducive to maintaining infection. This work evidences for the first time, through an entomological surveillance implemented on the basis of risk factor approach, the presence of West Nile and Usutu viruses in Piemonte and Liguria Regions (Northwestern Italy).

Keywords: Research; Abstracts; West Nile Virus; Usutu Virus.


Reconstruction of the #Evolutionary #History and Dispersal of #Usutu #Virus, a Neglected Emerging #Arbovirus in #Europe and #Africa (mBio, abstract)

[Source: mBio, full page: (LINK). Abstract, edited.]

Reconstruction of the Evolutionary History and Dispersal of Usutu Virus, a Neglected Emerging Arbovirus in Europe and Africa [      ]

Dimitri Engel a, Hanna Jöst a, Michael Wink b, Jessica Börstler a, Stefan Boschc, Mutien-Marie Garigliany d, Artur Jöst e, Christina Czajka a,e, Renke Lühken a, Ute Ziegler f, Martin H. Groschup f, Martin Pfeffer g, Norbert Becker e, Daniel Cadar a, Jonas Schmidt-Chanasit a,h

Author Affiliations: aBernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research, Hamburg, Germany bInstitute of Pharmacy and Molecular Biotechnology, Heidelberg University, Heidelberg, Germany cNature and Biodiversity Conservation Union (NABU), Stuttgart, Germany dDepartment of Veterinary Pathology, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium eGerman Mosquito Control Association (KABSeV), Speyer, Germany fFriedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute of Novel and Emerging Infectious Diseases, Greifswald-Insel Riems, Germany gFaculty of Veterinary Medicine, Institute of Animal Hygiene and Veterinary Public Health, University of Leipzig, Leipzig, Germany hGerman Centre for Infection Research (DZIF), partner site Hamburg-Luebeck-Borstel, Hamburg, Germany

Address correspondence to Daniel Cadar,

D.E., H.J., D.C., and J.S.-C. contributed equally to this article.

Editor Xiang-Jin Meng, Virginia Polytechnic Institute and State University



Usutu virus (USUV), one of the most neglected Old World encephalitic flaviviruses, causes epizootics among wild and captive birds and sporadic infection in humans. The dynamics of USUV spread and evolution in its natural hosts are unknown. Here, we present the phylogeny and evolutionary history of all available USUV strains, including 77 newly sequenced complete genomes from a variety of host species at a temporal and spatial scaled resolution. The results showed that USUV can be classified into six distinct lineages and that the most recent common ancestor of the recent European epizootics emerged in Africa at least 500 years ago. We demonstrated that USUV was introduced regularly from Africa into Europe in the last 50 years, and the genetic diversity of European lineages is shaped primarily by in situ evolution, while the African lineages have been driven by extensive gene flow. Most of the amino acid changes are deleterious polymorphisms removed by purifying selection, with adaptive evolution restricted to the NS5 gene and several others evolving under episodic directional selection, indicating that the ecological or immunological factors were mostly the key determinants of USUV dispersal and outbreaks. Host-specific mutations have been detected, while the host transition analysis identified mosquitoes as the most likely origin of the common ancestor and birds as the source of the recent European USUV lineages. Our results suggest that the major migratory bird flyways could predict the continental and intercontinental dispersal patterns of USUV and that migratory birds might act as potential long-distance dispersal vehicles.



Usutu virus (USUV), a mosquito-borne flavivirus of the Japanese encephalitis virus antigenic group, caused massive bird die-offs, mostly in Europe. There is increasing evidence that USUV appears to be pathogenic for humans, becoming a potential public health problem. The emergence of USUV in Europe allows us to understand how an arbovirus spreads, adapts, and evolves in a naive environment. Thus, understanding the epidemiological and evolutionary processes that contribute to the emergence, maintenance, and further spread of viral diseases is the sine qua non to develop and implement surveillance strategies for their control. In this work, we performed an expansive phylogeographic and evolutionary analysis of USUV using all published sequences and those generated during this study. Subsequently, we described the genetic traits, reconstructed the potential pattern of geographic spread between continents/countries of the identified viral lineages and the drivers of viral migration, and traced the origin of outbreaks and transition events between different hosts.



Citation Engel D, Jöst H, Wink M, Börstler J, Bosch S, Garigliany M, Jöst A, Czajka C, Lühken R, Ziegler U, Groschup MH, Pfeffer M, Becker N, Cadar D, Schmidt-Chanasit J. 2016. Reconstruction of the evolutionary history and dispersal of Usutu virus, a neglected emerging arbovirus in Europe and Africa. mBio 7(1):e01938-15. doi:10.1128/mBio.01938-15.

Received 6 November 2015 – Accepted 28 December 2015 – Published 2 February 2016

Copyright © 2016 Engel et al.

This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-ShareAlike 3.0 Unported license, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original author and source are credited.

Keywords: Research; Abstracts; Usutu Virus; Arbovirus; Flavivirus; Africa; Europe.