Enhanced production yields of rVSV-SARS-CoV-2 vaccine using Fibra-Cel® macrocarriers

The COVID-19 pandemic has led to high global demand for vaccines to safeguard public health. To that end, our institute has developed a recombinant viral vector vaccine utilizing a modified vesicular stomatitis virus (VSV) construct, wherein the G protein of VSV is replaced with the spike protein of SARS-CoV-2 (rVSV-ΔG-spike). Previous studies have demonstrated the production of a VSV-based vaccine in Vero cells adsorbed on Cytodex 1 microcarriers or in suspension. However, the titers were limited by both the carrier surface area and shear forces. Here, we describe the development of a bioprocess for rVSV-ΔG-spike production in serum-free Vero cells using porous Fibra-Cel® macrocarriers in fixed-bed BioBLU®320 5p bioreactors, leading to high-end titers. We identified core factors that significantly improved virus production, such as the kinetics of virus production, the use of macrospargers for oxygen supply, and medium replenishment. Implementing these parameters, among others, in a series of GMP production processes improved the titer yields by at least two orders of magnitude (2e9 PFU/mL) over previously reported values. The developed process was highly effective, repeatable, and robust, creating potent and genetically stable vaccine viruses and introducing new opportunities for application in other viral vaccine platforms

Exportation of Monkeypox Virus From the African Continent.

BACKGROUND: The largest West African monkeypox outbreak began September 2017, in Nigeria. Four individuals traveling from Nigeria to the United Kingdom (n = 2), Israel (n = 1), and Singapore (n = 1) became the first human monkeypox cases exported from Africa, and a related nosocomial transmission event in the United Kingdom became the first confirmed human-to-human monkeypox transmission event outside of Africa. METHODS: Epidemiological and molecular data for exported and Nigerian cases were analyzed jointly to better understand the exportations in the temporal and geographic context of the outbreak. RESULTS: Isolates from all travelers and a Bayelsa case shared a most recent common ancestor and traveled to Bayelsa, Delta, or Rivers states. Genetic variation for this cluster was lower than would be expected from a random sampling of genomes from this outbreak, but data did not support direct links between travelers. CONCLUSIONS: Monophyly of exportation cases and the Bayelsa sample, along with the intermediate levels of genetic variation, suggest a small pool of related isolates is the likely source for the exported infections. This may be the result of the level of genetic variation present in monkeypox isolates circulating within the contiguous region of Bayelsa, Delta, and Rivers states, or another more restricted, yet unidentified source pool

Lethal Dose 50% (LD50) values and virulence determinants

In the publication "Genome Sequence of Two Novel Virulent Clinical Strains of Burkholderia pseudomallei Isolated from Acute Melioidosis Cases Imported to Israel from India and Thailand" to which the online resource pertains, we report the genomes of two novel clinical isolates (MWH2021 and MST2022) of Burkholderia pseudomallei identified in two distinct acute cases of melioidosis diagnosed in two individuals arriving to Israel from India and Thailand, respectively. The publication includes preliminary genetic analysis of the genomes determining their phylogenetic classification in rapport to the genomes of other Burkholderia pseudomallei strains documented in the NCBI database. Inspection of the genetic data established the presence or absence of loci encoding for several important virulence determinants involved in the molecular pathogenesis of melioidosis. Virulence analysis in murine models of acute or latent melioidosis established that both strains belong to the highly virulent class of Burkholderia pseudomalleii.</p

Comprehensive analysis of co-occurring domain sets in yeast proteins

Abstract Background Protein domains are fundamental evolutionary units of protein architecture, composing proteins in a modular manner. Combinations of two or more, possibly non-adjacent, domains are thought to play specific functional roles within proteins. Indeed, while the number of potential co-occurring domain sets (CDSs) is very large, only a few of these occur in nature. Here we study the principles governing domain content of proteins, using yeast as a model species. Results We design a novel representation of proteins and their constituent domains as a protein-domain network. An analysis of this network reveals 99 CDSs that occur in proteins more than expected by chance. The identified CDSs are shown to preferentially include ancient domains that are conserved from bacteria or archaea. Moreover, the protein sets spanned by these combinations were found to be highly functionally coherent, significantly match known protein complexes, and enriched with protein-protein interactions. These observations serve to validate the biological significance of the identified CDSs. Conclusion Our work provides a comprehensive list of co-occurring domain sets in yeast, and sheds light on their function and evolution.</p

Supplementary Method Data

In the publication "Genome Sequence of Two Novel Virulent Clinical Strains of Burkholderia pseudomallei Isolated from Acute Melioidosis Cases Imported to Israel from India and Thailand" to which the online resource pertains, we report the genomes of two novel clinical isolates (MWH2021 and MST2022) of Burkholderia pseudomallei identified in two distinct acute cases of melioidosis diagnosed in two individuals arriving to Israel from India and Thailand, respectively. The publication includes preliminary genetic analysis of the genomes determining their phylogenetic classification in rapport to the genomes of other Burkholderia pseudomallei strains documented in the NCBI database. Inspection of the genetic data established the presence or absence of loci encoding for several important virulence determinants involved in the molecular pathogenesis of melioidosis. Virulence analysis in murine models of acute or latent melioidosis established that both strains belong to the highly virulent class of Burkholderia pseudomalleii.</p

Figure 1. <b>Phylogenetic tree </b><b><i>Burkholderia pseudomallei</i></b><b> strains</b>

Phylogenetic tree of Burkholderia pseudomallei (BP) strains. The genetic similarity of the strains.BP1, BP2, MAA2018, MWH2021 and MST 2022 to other BP strains was determined by comparative sequence analysis of all complete genomes of 128 BP strains available in the NCBI data base as of June 2023. The five clinical strains BP1, BP2, MAA2018, MWH2021 and MST 2022 were isolated from Melioidosis cases diagnosed in Israel in the past 6 years. See references 1 and 2 (below) for BP1, BP2 and MAA2018 (NCBI accession number SAMN11081001). The genomes of the novel clinical strains MWH2021 and MST2022 are available in the NCBI data base as: GCF_030913145.1 and GCA_030144945.1, respectively.Israeli O, Cohen-Gihon I, Brosh-Nissimov T, Zvi A, Beth-Din A, Shifman O, Israeli M, Elia U, Lazar S, Bar-Haim E, Cohen O, Chitlaru T. Draft Genome Sequence of a Rare Israeli Clinical Isolate of Burkholderia pseudomallei. Microbiol Resour Announc. 2019 May 9;8(19):e00281-19. doi: 10.1128/MRA.00281-19. Erratum in: Microbiol Resour Announc. 2019 Oct 3;8(40): PMID: 31072902; PMCID: PMC6509527.Brosh-Nissimov T, Grupel D, Abuhasira S, Leskes H, Israeli M, Lazar S, Elia U, Israeli O, Beth-Din A, Bar-Haim E, Cohen-Gihon I, Zvi A, Cohen O, Chitlaru T. Case Report: Imported Melioidosis from Goa, India to Israel, 2018. Am J Trop Med Hyg. 2019 Sep;101(3):580-584. doi: 10.4269/ajtmh.19-0303. Erratum in: Am J Trop Med Hyg. 2019</p

Insights from genomic analysis of a novel Coxiella burnetii strain isolated in Israel

The diagnosis of Q fever is challenging due to nonspecific symptoms and negative standard blood culture results. Serological testing through immunofluorescence assay (IFA) is the most commonly used method for diagnosing this disease. Polymerase chain reaction (PCR) tests can also be used to detect bacterial DNA if taken at an appropriate time. Once the presence of bacteria is confirmed in a sample, an enrichment step is required before characterizing it through sequencing. Cultivating C. burnetii is challenging as it can only be isolated by inoculation into cell culture, embryonated eggs, or animals. In this article, we describe the isolation of C. burnetii from a valve specimen in Vero cells. We conducted genome sequencing and taxonomy profiling of this isolate and were able to determine its taxonomic affiliation. Furthermore, Multispacer sequence typing (MST) analysis suggests that the infection originated from a local strain of C. burnetii found around northern Israel and Lebanon. This novel strain belongs to a previously described genotype MST6, harboring the QpRS plasmid, never reported in Israel