Characterization of Shuni viruses detected in Israel.

Shuni virus (SHUV) was recently identified in Israel in several brains of ovine, bovine, and goat fetuses and newborn animals with congenital arthrogryposis-hydranencephaly syndrome. In the present study, the sequences of several Israeli SHUV strains were analyzed in detail; based on the small genome segment which encodes the nucleocapsid protein and the small nonstructural protein (NSs), a very high similarity of 99-100 % among each other was found. In contrast to the highly conserved N protein, several mutations were found within the NSs-coding sequence of SHUVs present in brain samples of malformed fetuses, resulting in a considerably frequent appearance of stop codons. Interferon alpha/beta production was demonstrated in an in-vitro interferon bioassay; hence, the virus isolated from the brain of a malformed sheep fetus acquired mutations, resulting in the loss of its NSs protein function.

Genetic characterization of HA gene of low pathogenic H9N2 influenza viruses isolated in Israel during 2006-2012 periods.

H9N2 influenza viruses are isolated in Israel since 2000 and became endemic. From November 2006 to the beginning of 2012, many H9N2 viruses were identified, all belonged to the Asian G1-like lineage represented by A/qu/Hong Kong/G1/97 (H9N2). In the present study, 66 isolates were selected for their hemagglutinin gene characterization. Most H9N2 isolates were distributed between two main groups, identified as the 4th and 5th introductions. The 5th introduction, was represented by a compact cluster containing viruses isolated in 2011-2012; the 4th introduction was subdivided into two subgroups, A and B, each containing at least two clusters, which can be identified as A-1, A-2, B-1, and B2, respectively. Genetic analysis of the deduced HA proteins of viruses, belonging to the 4th and 5th introductions, revealed amino acid variations in 79 out of 542 positions. All isolates had typical low pathogenicity motifs at the hemagglutinin (HA) cleavage site. Most viruses had leucine at position 216 in a receptor binding pocket that enables the virus to bind successfully with the cellular receptors intrinsic to mammals, including humans. It was shown that the differences between the HA proteins of viruses used for vaccine production and local field isolates increased in parallel with the duration and intensity of vaccine use, illustrating the genetic diversity of the H9N2 viruses in Israel.

Features of p53 protein distribution in the corneal epithelium and corneal tear film.

Tumor suppressor protein p53 is the key factor in the regulation of cell proliferation. Its concentration is low in the cytoplasm of most cell types. However, in corneal epithelium cells, abnormally high p53 content is detected. The aim of the present study was to characterize p53 distribution in the corneal epithelium. For this purpose, immunohistochemistry, western blot analysis and electronic microscope examinations were performed. A low level of p53 was identified in the lens, iris and retina; by contrast, a significantly high concentration of this protein was observed in the corneal epithelium. In opposite, MDM2 was identified in the lens, iris and retina while it is completely absent in the corneal epithelium. In addition, we found a significant amount of exosomes and other microvesicles containing p53 in the corneal mucin layer. We thus hypothesize that a significantly high level of p53 was caused by a combination of absents of MDM2 in parallel with p53 microvesicles storage.

Genetic characterization of the H9N2 influenza viruses circulated in the poultry population in Israel.

The partial nucleotide sequences of the hemagglutinin (HA) genes of 72 H9N2 influenza viruses isolated from chickens and turkeys in Israel during the period 2000-2005 were genetically analyzed. The isolates possessed the three types of amino acid motif -R-S-S-R/G-L-, -R-S-N-R/G-L-, and -R-S-K-R/G-L- at the cleavage site of HA. Phylogenetic analyses showed that all Israeli isolates belonged to the same group which further divided into three closely related sub-groups. The HA genes of these isolates were related to the HA gene of A/chicken/Germany/R45/98 isolated from chicken in Germany in 1998.

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.

Genetic characterization of H5N1 influenza virus that caused new outbreak in Israel at the beginning of 2008.

Our aim was to characterize the A/ck/Israeli/1055/2008 (H5N1) avian influenza virus that was isolated at the beginning of 2008, and to establish the phylogenetic relationship of this isolate to other H5N1 viruses that were recently isolated in adjacent countries. In light of a study of complete nucleotide sequences of all the genes we found that the isolate (year 2008) was closely related to the H5N1 viruses isolated in Egypt, Israel and Gaza in 2006. The Israeli isolate had the hemagglutinin-connecting peptide with a polybasic amino acid insertion. The most host-restriction sites of the 2008 isolate were typical of avian hosts, with one exception: K627 at the PB2 protein. As compared with previous local H5N1 isolates, a high mutation rate was found at the HA gene, which antigenic sites were under positive selection pressure.

Modulation of the severity of highly pathogenic H5N1 influenza in chickens previously inoculated with Israeli H9N2 influenza viruses.

The continued evolution of H9N2 and H5N1 viruses and their spread and re-emergence across Eurasia raise concern that prior H9N2 virus infection may limit the detection of subsequent H5N1 infection in gallinaceous poultry by attenuating the severity of disease. We show that H9N2 viruses isolated from Israeli turkeys during 2000-2004 were antigenically and genetically distinguishable. These three H9N2 viruses caused no overt signs of disease in chickens. The 2004 isolate replicated and spread most efficiently, and chickens previously inoculated with this H9N2 virus showed 90%-100% survival after inoculation 1 to 35 days later with lethal H5N1 virus. Chickens that survived did not show signs of disease but did shed lethal H5N1 virus from the cloaca. The modulation of survivability was time-dependent; the effect was maximal 5 days after H9N2 inoculation. These findings suggest that co-circulation of H9N2 viruses can contribute to the spread of lethal H5N1 viruses.

Phylogenetic analysis of hemagglutinin, neuraminidase, and nucleoprotein genes of H9N2 avian influenza viruses isolated in Israel during the 2000-2005 epizootic.

The first two isolates of H9N2 influenza virus in Israel were collected from turkey and chicken hosts in May 2000. The actual epizootic of the H9N2 virus started in December 2001, after a 1.5-year period of silence, and still continues. A total of more than 500 isolations from turkeys and chickens were registered during the outbreaks. The present study has revealed some genetic peculiarities among the local isolates, namely: all the isolates belong to the same G1-like phylogenetic lineage, within which they form a single group, which, in turn, is divided into three subgroups in the cases of the HA and NP genes, and two subgroups in the case of the NA gene. The results present a basis for suggesting the existence of two parallel evolutionary trends originating from the same local "prototype" isolate.

Genetic characterization of avian influenza viruses isolated in Israel during 2000-2006.

Our aim was to establish the phylogenetic and genetic relationships among avian influenza viruses (AIV) recently isolated from poultry in Israel. During this study we analyzed complete nucleotide sequences of two envelope (hemagglutinin and neuraminidase) and six internal genes (polymerase B1, polymerase B2, polymerase A, nucleoprotein, nonstructural, and matrix) of 29 selected H9N2 and six internal genes of five H5N1 viruses isolated in Israel during 2000-2006. Comparative genetic and phylogenetic analyses of these sequences revealed that the local H5N1 viruses are closely related to H5N1 viruses isolated in European, Asian, and Middle Eastern countries in 2005-2006. The H9N2 Israeli isolates, together with viruses isolated in Jordan and Saudi Arabia formed a single group. Our data support the claim that during recent years a new endemic focus of H9N2 has been formed in the Middle East. The introduction of H5N1 and co-circulation of these two subtypes of AIV in this region may augment the risk of potentially pandemic strains emergence.

Molecular characterization of the glycoprotein genes of H5N1 influenza A viruses isolated in Israel and the Gaza Strip during 2006 outbreaks.

Highly pathogenic H5N1 avian influenza A viruses (AIV) have caused outbreaks among domestic poultry and wild aquatic birds in many Asian, European, and African countries since 1997. In March 2006 an avian H5N1 influenza A virus was isolated from poultry in Israel. In the present study we molecularly characterized the hemagglutinin (HA) and neuraminidase (NA) genes of eleven H5N1 viruses isolated from domestic poultry in Israel and Gaza in March-April 2006. Phylogenetic analysis of the HA and NA genes showed that the Israeli and Gazian viruses were closely related to viruses isolated in Egypt in 2006.

Genetic analysis of nonstructural genes (NS1 and NS2) of H9N2 and H5N1 viruses recently isolated in Israel.

The avian influenza virus subtype H9N2 affects wild birds, domestic poultry, swine, and humans; it has circulated amongst domestic poultry in Israel during the last 6 years. The H5N1 virus was recorded in Israel for the first time in March 2006. Nonstructural (NS) genes and NS proteins are important in the life cycle of the avian influenza viruses. In the present study, NS genes of 21 examples of H9N2 and of two examples of H5N1 avian influenza viruses, isolated in Israel during 2000-2006, were completely sequenced and phylogenetically analyzed. All the H9N2 isolates fell into a single group that, in turn, was subdivided into three subgroups in accordance with the time of isolation; their NS1 and NS2 proteins possessed 230 and 121 amino acids, respectively. The NS1 protein of the H5N1 isolates had five amino acid deletions, which was typical of highly pathogenic H5N1 viruses isolated in various countries during 2005-2006. Comparative analysis showed that the NS proteins of the H9N2 Israeli isolates contained few amino acid sequences associated with high pathogenicity or human host specificity.