Evolution and Phylogenetic Analysis of Full-Length VP3 Genes of Eastern Mediterranean Bluetongue Virus Isolates

Bluetongue virus (BTV) is the ‘type’ species of the genus Orbivirus within the family Reoviridae. The BTV genome is composed of ten linear segments of double-stranded RNA (dsRNA), each of which codes for one of ten distinct viral proteins. Previous phylogenetic comparisons have evaluated variations in genome segment 3 (Seg-3) nucleotide sequence as way to identify the geographical origin (different topotypes) of BTV isolates. The full-length nucleotide sequence of genome Seg-3 was determined for thirty BTV isolates recovered in the eastern Mediterranean region, the Balkans and other geographic areas (Spain, India, Malaysia and Africa). These data were compared, based on molecular variability, positive-selection-analysis and maximum-likelihood phylogenetic reconstructions (using appropriate substitution models) to 24 previously published sequences, revealing their evolutionary relationships. These analyses indicate that negative selection is a major force in the evolution of BTV, restricting nucleotide variability, reducing the evolutionary rate of Seg-3 and potentially of other regions of the BTV genome. Phylogenetic analysis of the BTV-4 strains isolated over a relatively long time interval (1979–2000), in a single geographic area (Greece), showed a low level of nucleotide diversity, indicating that the virus can circulate almost unchanged for many years. These analyses also show that the recent incursions into south-eastern Europe were caused by BTV strains belonging to two different major-lineages: representing an ‘eastern’ (BTV-9, -16 and -1) and a ‘western’ (BTV-4) group/topotype. Epidemiological and phylogenetic analyses indicate that these viruses originated from a geographic area to the east and southeast of Greece (including Cyprus and the Middle East), which appears to represent an important ecological niche for the virus that is likely to represent a continuing source of future BTV incursions into Europe

A STUDY OF THE BOVINE HERPESVIRUS TYPE 6 (BHV) INFECTION OF GOATS

GOAT HERPESVIRUS (BHV-6 OR CHV-1) IS WIDESPREAD IN GREECE (49,6% POSITIVE GOATSAND 82,9% POSITIVE HERDS BY SERUM NEUTRALIZATION TEST). EFFORTS FOR VIRUS ISOLATION FROM VARIOUS PATHOLOGICAL MATERIAL TAKEN FROM DEAD OR ALIVE KIDS AND GOATS OR FROM ABORTED FETUSES, WERE UNSUCCESSFUL. THE INFECTION AMONG GOATS WITHIN A HERD SPREADS MOST COMMONLY DURING THE SUMMERTIME AND FOLLOWS THE BREEDING SEASON. FROM THE LITERATURE AND OUR EXPERIMENTAL DATA IT SEEMS THAT THE PURE BREEDS OF GOATS (E.G. SAANEN) ARE MORE SENSITIVE TO THIS HERPESVIRUS INFECTION THAN THE GREEK BREED OF CAPRA PRISCA. IT HAS NOT BEEN SHOWN THAT THE INFECTION IN EXPERIMENTALLY INOCULATED LAMBS DEPENDS ON THEIR AGE.ΜΕ ΤΗ ΔΟΚΙΜΗ ΤΗΣ ΟΡΟΕΞΟΥΔΕΤΕΡΩΣΗΣ ΔΙΑΠΙΣΤΩΣΑΜΕ ΟΤΙ Ο ΕΡΠΗΤΟΠΟΙΟΣ ΤΩΝ ΑΙΓΩΝ BHV-6 ('Η CHV-1) ΕΙΝΑΙ ΠΟΛΥ ΔΙΑΔΕΔΟΜΕΝΟΣ ΣΤΗ ΧΩΡΑ ΜΑΣ (ΠΟΣΟΣΤΟ ΘΕΤΙΚΟΤΗΤΑΣ ΑΙΓΩΝ 49,56% ΚΑΙ ΠΟΣΟΣΤΟ ΘΕΤΙΚΟΤΗΤΑΣ ΠΟΙΜΝΙΩΝ 82,85%). ΔΕΝ ΑΠΟΜΟΝΩΘΗΚΕ ΟΜΩΣ ΑΠΟ ΔΙΑΦΟΡΑΠΑΘΟΛΟΓΙΚΑ ΥΛΙΚΑ ΠΟΥ ΠΑΡΘΗΚΑΝ ΑΠΟ ΝΕΚΡΑ 'Η ΖΩΝΤΑΝΑ ΕΡΙΦΙΑ, ΕΝΗΛΙΚΑ ΖΩΑ 'Η ΕΜΒΡΥΑ, ΠΟΥ ΕΙΧΑΝ ΑΠΟΒΛΗΘΕΙ. Η ΕΠΙΖΩΟΤΙΟΛΟΓΙΚΗ ΕΡΕΥΝΑ ΣΕ ΦΥΣΙΚΑ ΜΟΛΥΣΜΕΝΑ ΠΟΙΜΝΙΑ ΑΙΓΩΝ ΕΔΕΙΞΕ ΟΤΙ ΟΙ ΜΟΛΥΝΣΕΙΣ ΣΥΜΒΑΙΝΟΥΝ ΚΥΡΙΩΣ ΤΟ ΚΑΛΟΚΑΙΡΙ ΚΑΙ ΙΔΙΑΙΤΕΡΑ ΚΑΤΑ ΤΗΝ ΠΕΡΙΟΔΟ ΤΗΣ ΟΧΕΙΑΣ. ΑΠΟ ΤΑ ΕΥΡΗΜΑΤΑ ΤΗΣ ΠΕΙΡΑΜΑΤΙΚΗΣ ΜΟΛΥΝΣΗΣ ΜΕ ΤΟΝ ΙΟ (ΣΤΕΛΕΧΟΣ E/CH), ΕΡΙΦΙΩΝ ΦΥΛΗΣ SAANEN ΚΑΙ ΕΡΙΦΙΩΝ ΕΓΧΩΡΙΑΣ ΦΥΛΗΣ (CAPRA PRISCA) ΦΑΙΝΕΤΑΙ ΟΤΙ ΟΙ ΚΑΘΑΡΟΑΙΜΕΣ ΦΥΛΕΣ ΕΙΝΑΙ ΠΙΟ ΕΥΑΙΣΘΗΤΕΣ ΣΤΗ ΛΟΙΜΩΞΗ ΑΠΟ ΤΗΝ ΕΓΧΩΡΙΑ. ΔΕΝ ΔΙΑΠΙΣΤΩΘΗΚΕ ΠΕΙΡΑΜΑΤΙΚΑ Η ΠΑΡΑΜΟΝΗ ΤΟΥ ΕΡΠΗΤΟΙΟΥ ΑΥΤΟΥ ΣΕ ΛΑΝΘΑΝΟΥΣΑ ΚΑΤΑΣΤΑΣΗ. ΤΕΛΟΣ, Η ΠΕΙΡΑΜΑΤΙΚΗ ΜΟΛΥΝΣΗ ΑΜΝΩΝ (ΜΗ ΦΥΣΙΚΟΙ ΞΕΝΙΣΤΕΣ) ΕΔΕΙΞΕ ΟΤΙ Η ΜΟΡΦΗ ΤΗΣ ΛΟΙΜΩΞΗΣ ΚΑΘΩΣ ΚΑΙ Η ΑΠΟΒΟΛΗ 'Η ΟΧΙ ΤΟΥ ΙΟΥ ΑΠΟ ΑΥΤΑ ΕΞΑΡΤΑΤΑΙ ΑΠΟ ΤΗΝ ΗΛΙΚΙΑ ΤΩΝ ΠΕΙΡΑΜΑΤΟΖΩΩΝ

First incidence of clinical signs of nodavirus infection in sea bream, Sparus auratus L

The causal agent of viral encephalopathy and retinopathy in fish is an RNA virus known as nodavirus, a member of the Nodaviridae family. According to published data, sea bream (Sparus aurata L.) that are infected with the virus show no clinical signs and are considered an asympto- matic carrier. In this paper we report for the first time a clinical case of nodavirus in commercially reared sea bream. Fish with clinical signs underwent necropsy and routine microbiological, para- sitological, and histopathological examination. The virus was detected by RT-PCR and isolated in SSN-1 cell cultures. The results described in this study demonstrate the presence of a nodavirus agent that can infect sea bream in sea water, causing a disease similar to that observed in marine sea bass but with lower mortality and milder neurological signs. Histopathological lesions were also similar to those observed in sea bass infected with nodavirus

Molecular analysis of the NS3/NS3A gene of Bluetongue virus isolates from the 1979 and 1998-2001 epizootics in Greece and their segregation into two distinct groups

The sequence of the genome segment 10 (Seg-10) encoding NS3/NS3A was determined for 19 field isolates of Bluetongue virus (BTV) of serotypes BTV-1, BTV-4, BTV-9 and BTV-16, derived from epizootics in Greece in the years 1979 and 1998–2001. The aim of the study was to define the molecular epidemiology of the virus in this part of the Mediterranean basin. On the basis of the Seg-10 sequences, the isolates grouped into two distinct phylogenetic clusters. These were Greek group I of solely serotype BTV-4 viruses, and Greek group II of serotypes BTV-1, BTV-9 and BTV-16 viruses. The isolates in Greek group I clustered with the Corsican and Tunisian BTV-2 serotypes and US group II strains of BTV-10 and BTV-13 serotypes, while those in Greek group II with Chinese, Indian and Australian viruses of different sterotypes suggesting that viruses derived from two distinct ecosystems have caused BT incursions in Greece over the last 25 years. The NS3/NS3A sequences of most of the BTV-4 isolates were identical, irrespective of the year of isolation, geographical location and host species or tissue origin. Maximum of 15–16% nucleic acid sequence variation, but only 4% deduced amino acid substitution, were observed between groups I and II. Furthermore, the clustering of the NS3/NS3A sequences was independent of the viral serotype, indicating the occurrence of genome segment reassortment during the course of evolution of the viruses

Evidence of Schmallenberg virus circulation in ruminants in Greece

International audienceDuring March 2013, we investigated the presence and the levels of Schmallenberg virus (SBV) circulation in three dairy cow herds and three sheep flocks in Central Macedonia, Greece. In two cow herds, a high number of abortions had been observed during the winter. Six bulk-tank milk samples and 147 individual sera were screened for SBV-specific antibodies by ELISA. Positive reactions were obtained from 5 out of 6 bulk-tank milk samples, 58 out of 90 sera from the 3 cow herds, and 2 sera from 2 of the 3 sheep flocks. Twenty-two ELISA-positive sera were tested by serum neutralization test (SNT). SNT confirmed the presence of neutralizing antibodies against SBV in all samples tested, with titers ranging between 1:32 and a parts per thousand yen1:256. No neutralizing antibodies against Akabane virus (AKAV) or Shamonda virus (SHAV) were detected, indicating that neutralizing antibodies against SBV do not cross react with AKAV or SHAV in SNT. ELISA testing of bulk-tank milk samples proved to be convenient and reliable. None of the tested sera was found positive for SBV by real-time RT-PCR, indicating that the sampling was conducted past the viremia stage. This is the first report of SBV circulation in Greece

Evaluation of a West Nile virus surveillance and earlywarning system in Greece, based on domestic pigeons

In the summer of 2010 an epidemic of West Nile virus (WNV) occurred in Central Macedo-nia, Greece, with 197 human neuroinvasive disease (WNND) cases. In the following yearsthe virus spread to new areas, with a total of 76 WNND cases in 2011, and 109 WNNDcases in 2012 (14 and 12 WNND cases, respectively, in Central Macedonia). We establisheda surveillance system based on serological testing of domestic pigeons, using cELISA con-firmed by serum neutralization test. In Central Macedonia, pigeon seroprevalence was 54%(95% CI: 49â59%) and 31% (95% CI: 24â37%) at the end of the 2010 and 2011 epidemicseasons, respectively. One serum was positive for neutralizing antibodies directed againstUsutu virus. Pigeon WNV seroprevalence and incidence rates of human WNND after the2010 epidemic were positively correlated ( = 0.94, at the regional unit level), while in2011 the correlation ( = 0.56) was not statistically significant, possibly due to small num-ber of human WNND cases recorded. To evaluate the efficacy of the system at alerting uponWNV enzootic circulation before the onset of human cases, we tested 270 pigeons in 2011and 240 pigeons in 2012. In Central Macedonia, the first seroconversions in pigeons wererecorded 44 and 47 days, respectively, before the first human WNND cases. Pigeon surveil-lance was used successfully for identification of areas with WNV enzootic transmissionand for early warning. Timely diffusion of information to health authorities facilitated theimplementation of preparedness plans to protect public health

Evaluation of a West Nile virus surveillance and early warning system in Greece, based on domestic pigeons

In the summer of 2010 an epidemic of West Nile virus (WNV) occurred in Central Macedonia, Greece, with 197 human neuroinvasive disease (WNND) cases. In the following years the virus spread to new areas, with a total of 76 WNND cases in 2011, and 109 WNND cases in 2012 (14 and 12 WNND cases, respectively, in Central Macedonia). We established a surveillance system based on serological testing of domestic pigeons, using cELISA confirmed by serum neutralization test In Central Macedonia, pigeon seroprevalence was 54% (95% CI: 49-59%) and 31% (95% CI: 24-37%) at the end of the 2010 and 2011 epidemic seasons, respectively. One serum was positive for neutralizing antibodies directed against Usutu virus. Pigeon WNV seroprevalence and incidence rates of human WNND after the 2010 epidemic were positively correlated (rho = 0.94, at the regional unit level), while in 2011 the correlation (rho = 0.56) was not statistically significant, possibly due to small number of human WNND cases recorded. To evaluate the efficacy of the system at alerting upon WNV enzootic circulation before the onset of human cases, we tested 270 pigeons in 2011 and 240 pigeons in 2012. In Central Macedonia, the first seroconversions in pigeons were recorded 44 and 47 days, respectively, before the first human WNND cases. Pigeon surveillance was used successfully for identification of areas with WNV enzootic transmission and for early warning. Timely diffusion of information to health authorities facilitated the implementation of preparedness plans to protect public health. (C) 2014 Elsevier Ltd. All rights reserved