Characterization of bluetongue virus serotype 28.

Bluetongue virus (Reoviridae; Orbivirus, BTV), which is usually transmitted by biting midges, affects wild and domestic ruminants worldwide, thereby causing an economically important disease. Recently, a putative new BTV strain was isolated from contaminated vaccine batches. In this study, we investigated the genomic and clinical characteristics of this isolate, provisionally designated BTV-28. Phylogenetic analysis of BTV-28 segment 2 (Seg-2) showed that it is related to Seg-2 from BTV serotypes 4, 10, 11, 17, 20 and 24, sharing 64%-66% identity in nucleotide sequences (nt) and 59%-62% in amino acid (aa) sequences of BTV VP2. BTV-28 Seg-6 is related to the newly reported XJ1407 BTV isolate, sharing 76.70% nt and 90.87% aa sequence identity. Seg-5 was most closely related to a South African BTV-4 strain, and all other segments showed close similarity to BTV-26. Experimental infection by injection of 6-month-old ewes caused clinical signs in all injected animals, lasting from 2 to 3 days to several weeks post-infection, including high body temperature, conjunctivitis, nasal discharge and rhinitis, facial oedema, oral hyperaemia, coronitis, cough, depression and tongue cyanosis. Naïve control animals, placed together with the infected sheep, displayed clinical signs and were positive for viral RNA, but their acute disease phase was shorter than that of BTV-injected ewes. Control animals that were kept in a separated pen did not display any clinical signs and were negative for viral RNA presence throughout the experiment. Seroconversion was observed in the injected and in one of the two contact-infected animals. These findings demonstrate that BTV-28 infection of sheep can result in clinical manifestation, and the clinical signs detected in the contact animals suggest that it might be directly transmitted between the mammalian hosts.

Serological evidence suggests that several Simbu serogroup viruses circulated in Israel.

Viruses of the Simbu serogroup are arboviruses that are known to cause outbreaks of abortion, stillbirth and congenitally deformed neonates. This study presents the results of antibody screening of Simbu serogroup viruses in heifers born in Israel after October 2013, and in adult milking cows born before May 2012. Thirteen dairy cattle farms in five regions, and one sheep flock, entered this study. Serum samples that were found to be positive by ELISA were further tested by specific virus- neutralization test against a panel of Simbu serogroup viruses including Akabane, Aino, Sathuperi, Shamonda, and Peaton viruses. Antibody detection in lactating adult cows revealed that several viruses were circulating in Israel between 2008-2014. Moreover, during autumn 2014 the heifers became serum-positive after being exposed to more than one Simbu serogroup virus concurrently. The results of this study shed new light on Simbu virus infections in Israel, and may contribute to the epidemiology of the Simbu serogroup around the Mediterranean Basin in general.

Middle East respiratory syndrome coronavirus specific antibodies in naturally exposed Israeli llamas, alpacas and camels.

Thus far, no human MERS-CoV infections have been reported from Israel. Evidence for the circulation of MERS-CoV in dromedaries has been reported from almost all the countries of the Middle East, except Israel. Therefore, we aimed to analyze MERS-CoV infection in Israeli camelids, sampled between 2012 and 2017. A total of 411 camels, 102 alpacas and 19 llamas' sera were tested for the presence of antibodies to MERS-CoV. Our findings indicate a lower MERS-CoV seropositivity among Israeli dromedaries than in the surrounding countries, and for the first time naturally infected llamas were identified. In addition, nasal swabs of 661 camels, alpacas and lamas, obtained from January 2015 to December 2017, were tested for the presence of MERS-CoV RNA. All nasal swabs were negative, indicating no evidence for MERS-CoV active circulation in these camelids during that time period.

Seroprevalence and risk factor analysis for exposure to equine encephalosis virus in Israel, Palestine and Jordan.

Equine encephalosis virus (EEV) is an orbivirus transmitted by Culicoides species. Most infected horses show mild clinical signs and mortality is usually very low. EEV is closely related and similarly transmitted to other, more pathogenic and economically important, orbiviruses such as African horse sickness virus (AHSV), bluetongue virus (BTV) and epizootic haemorrhagic disease viruses (EHDV), and may serve as an indicator for possible transmission of the latter. Israel has been reported to be endemic for EEV since 2001. This study was initiated to re-evaluate the current seroprevalence and risk factors for EEV exposure in Israel, and to assess, for the first time, the seroprevalence of EEV in Palestine and Jordan. Three hundred and sixteen serum samples were collected from apparently healthy horses at 21 farms in Israel, 66 horses at nine farms in Palestine and 100 horses at three farms in Jordan. The presence of EEV antibodies was detected by a serum neutralization assay. Seroprevalence of EEV was 58.2% (184/316 horses) in Israel, 48.5% (32/66 horses) in Palestine and 2% (2/100 horses) in Jordan. Seroprevalence in Jordan was significantly lower than in Israel and Palestine (P < 0.001). The farm (P < 0.001) and horse age (P = 0.003) were found as significant risk factors for EEV exposure in Israel in multivariable statistical analysis. The results of this study further demonstrate that EEV is no longer limited to South Africa and is endemic in both Israel and Palestine and horses in Jordan were also exposed to this virus emphasizing the potential of pathogens to invade new ecological niches.

A high-resolution melting (HRM) assay for the differentiation between Israeli field and Neethling vaccine lumpy skin disease viruses.

Lumpy skin disease (LSD) is a constant threat to the Middle East including the State of Israel. During vaccination programs it is essential for veterinary services and farmers to be able to distinguish between animals affected by the cattle-borne virulent viruses and vaccinated animals, subsequently affected by the vaccine strain. This study describes an improved high resolution-melting (HRM) test that exploits a 27 base pair (bp) fragment of the LSDV126 extracellular enveloped virion (EEV) gene that is present in field viruses but is absent from the Neethling vaccine strain. This difference leads to ∼0.5 °C melting point change in the HRM assay, when testing the quantitative PCR (qPCR) products generated from the virulent field viruses compared to the attenuated vaccine. By exploiting this difference, it could be shown using the newly developed HRM assay that virus isolated from vaccinated cattle that developed disease symptoms behave similarly to vaccine virus control, indicating that the vaccine virus can induce disease symptoms. This assay is not only in full agreement with the previously published PCR gradient and restriction fragment length polymorphism (RFLP) tests but it is faster with, fewer steps, cheaper and dependable.

Bluetongue virus serotype 24 (BTV-24) in Israel: phylogenetic characterization and clinical manifestation of the disease.

Bluetongue (BT), an arthropod-borne viral disease of ruminants, a ects sheep most severely than other domestic animals. Bluetongue virus serotype 24 (BTV-24) is one of 26 known Bluetongue virus (BTV) serotypes. In this article, we present data of phylogenetic analysis of 9 viral genes (Seg1, Seg2, Seg3, Seg4, Seg5, Seg6, Seg8, Seg9, and Seg10) from 8 Israeli BTV-24 isolates and relate the genotype of the BTV-24 isolates to their phenotype with regard to clinical manifestations. The high level of genetic identity (> 99.6%) between Seg2, Seg4 and Seg5 in all 8 BTV-24 isolates indicated that these segments shared the same viral ancestor. Phylogenetic analysis of Seg1, Seg3, Seg5, Seg8, Seg9, and Seg10 revealed that the Israeli BTV-24 strains comprised 4 variants. Five of the viruses revealed high identity among all 9 segments, and represented variant 1. A second variant (BTV24/3027/6/10), isolated in 2010, showed signi cant variation from variant 1 in 3 gene segments (VP-1, VP-3, and NS-3 genes). A third variant (BTV24/3027/1/10) showed signi cant variation from variant 1 in 6 segments (VP-1, VP-3, VP-6 and NS-1, NS-2 and NS-3 genes), while a fourth variant (BTV24/2214/1/10) showed signi cant variation from variant 1 in 4 segments (VP-1, NS-1, NS-2 and NS-3 genes). These marked di erences in sequence identity indicate that a high level of genetic reassortment is occurring between co-circulating BTV strains in Israel.