MEEGID 2300

No. of Pages 5, Model 5G

4 April 2015 Infection, Genetics and Evolution xxx (2015) xxx–xxx 1

Contents lists available at ScienceDirect

Infection, Genetics and Evolution journal homepage: www.elsevier.com/locate/meegid

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Short communication

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Emergence of multireassortant bluetongue virus serotype 4 in Hungary

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Ákos Hornyák a, Péter Malik a, Szilvia Marton b, Renáta Dóró b, Daniel Cadar c, Krisztián Bányai b,⇑ a

Veterinary Diagnostic Directorate, National Food Chain Safety Office, Budapest, Hungary Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, Budapest, Hungary c Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, Hamburg, Germany b

a r t i c l e

i n f o

Article history: Received 19 December 2014 Received in revised form 26 March 2015 Accepted 28 March 2015 Available online xxxx Keywords: Bluetongue Outbreak Reassortment Recombination Semiconductor sequencing Phylogenetic analysis

a b s t r a c t The genome sequence and the phylogenetic relationships of a serotype 4 bluetongue virus (BTV-4) emerged during 2014 in Hungary are described in this study. Genome segment 2 encoding the major neutralization antigen, VP2, shared moderate sequence similarity (nt, 694.3%) with the corresponding gene of contemporary and historic homotypic bluetongue viruses, whereas genome segments S1, S4, S5, S7–S10 were typically more closely related to the cognate genes of heterotypic isolates. Importantly, in many gene phylogenies the Hungarian BTV-4 strain showed genetic relationship to BTV strains identified in outbreaks in the western Mediterranean basin. Our results indicate the identified Hungarian bluetongue virus strain evolved through reassortment involving multiple genome segments from various heterotypic bluetongue viruses. Ó 2015 Published by Elsevier B.V.

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Bluetongue (BT) is an emerging arthropod-borne disease in Europe, which has been responsible for outbreaks in the Mediterranean basin (MB) and more recently in Western, Central and even Northern Europe (Verwoerd and Erasmus, 2004; Saegerman et al., 2008). Among other factors, climate change and extended vector competence have been commonly implicated in the changing epizootiology of BT in Europe (Saegerman et al., 2008). BT is caused by an orbivirus, bluetongue virus (BTV), and affects ruminant species, mainly sheep and cattle. BTV is characterized by a non-enveloped round shaped multilayered virion that encases the 10-segmented double-stranded RNA genome (Roy, 2008). BTV is classified into serotypes based on the genetic and antigenic features of the main neutralization antigen, VP2. The distribution of serotypes shows peculiar geographic pattern. For example, among the 27 serotypes (Maan et al., 2011; Zientara et al., 2014), serotypes 1, 2, 4, 6, 8, 9, and 16 BTVs were repeatedly identified over the past two decades in different European countries (Saegerman et al., 2008; van Rijn et al., 2012). In general, BT outbreaks in Europe can be linked to the incursions of virus strains from North Africa invading primarily southern and western European countries (i.e., the western MB epidemiologic system) and to the dispersal of virus strains from the Near and Middle

⇑ Corresponding author at: Institute for Veterinary Medical Research, Centre for Agricultural Research, Hungarian Academy of Sciences, H-1143 Budapest, Hungária krt. 21, Hungary. Tel.: +36 1467 4060; fax: +36 1467 4076. E-mail address: [email protected] (K. Bányai).

East into the Balkan peninsula (i.e., the eastern MB epidemiologic system) (Saegerman et al., 2008). Incursions associated with serotype 4 BTV (BTV-4) strains in Europe were first recorded on Greek Islands during the late 1970s and then again in Greece, Bulgaria and Turkey in 1998– 1999. These outbreaks were associated with strains characteristic to the eastern MB epidemiologic system. Subsequent outbreaks in Italy, France, Spain and Portugal from mid-2000s onward were caused by a different lineage most typical to the western MB epidemiologic system (Barros et al., 2007; Breard et al., 2007; Saegerman et al., 2008; Lorusso et al., 2013). Consequently, BTV-4 strains detected in the two epidemiologic systems can be classified into two phylogenetic lineages on the basis of their geographical origins (Breard et al., 2007). Historically, no data about the occurrence of BT have been available in Hungary until 2007 when serological assays identified seropositive cattle newly imported from another European country affected by BT (Malik et al., 2008). Subsequently, from 2007 onward >300,000 livestock sera were processed for serological testing and >40,000 blood samples were tested for direct virus detection by RT-PCR. Between 2007 and 2013 serological assays detected an overall

Emergence of multireassortant bluetongue virus serotype 4 in Hungary.

The genome sequence and the phylogenetic relationships of a serotype 4 bluetongue virus (BTV-4) emerged during 2014 in Hungary are described in this s...
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