Human Infection With IsrRAPXV: A Novel Zoonotic Bat-Derived Poxvirus.

Background: Bats are recognized as the natural reservoir of several zoonotic viruses that pose a threat to public health worldwide. In our recent reports, we describe the identification of a novel poxvirus, IsrRAPXV, in Egyptian fruit bats. This poxvirus is associated with high morbidity and mortality in bats.

Identification, Isolation, and Molecular Characterization of in .

Coronaviruses (CoVs) are enveloped viruses with a large RNA genome (26 to 32 kb) and are classified into four genera: , , and . CoV infections cause respiratory, enteric, and neurologic disorders in mammalian and avian species. In 2019, Oryx leucoryx animals suffered from severe hemorrhagic diarrhea and high morbidity rates.

5' Untranslated mRNA Regions Allow Bypass of Host Cell Translation Inhibition by Legionella pneumophila.

Legionella pneumophila grows within membrane-bound vacuoles in alveolar macrophages during human disease. Pathogen manipulation of the host cell is driven by bacterial proteins translocated through a type IV secretion system (T4SS). Although host protein synthesis during infection is arrested by the action of several of these translocated effectors, translation of a subset of host proteins predicted to restrict the pathogen is maintained.

Identification and Genetic Characterization of Viral Pathogens in Ruminant Gestation Abnormalities, Israel, 2015-2019.

Infectious agents including viruses are important abortifacients and can cause fetal abnormalities in livestock animals. Here, samples that had been collected in Israel from aborted or malformed ruminant fetuses between 2015 and 2019 were investigated for the presence of the following viruses: the reoviruses bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV), the flaviviruses bovine viral diarrhea virus (BVDV) and border disease virus (BDV), the peribunyaviruses Shuni virus (SHUV) and Akabane virus (AKAV), bovine herpesvirus type 1 (BoHV-1) and bovine ephemeral fever virus (BEFV). Domestic (cattle, sheep, goat) and wild/zoo ruminants were included in the study.

Characterization of Winter Dysentery Bovine Coronavirus Isolated from Cattle in Israel.

Bovine coronavirus (BCoV) is the causative agent of winter dysentery (WD). In adult dairy cattle, WD is characterized by hemorrhagic diarrhea and a reduction in milk production. Therefore, WD leads to significant economic losses in dairy farms.

Israeli Pox Virus (IsrRAPXV) Infection in Juvenile Egyptian Fruit Bat (): Clinical Findings and Molecular Detection.

During 2019, five carcasses of juvenile Egyptian fruit bats () were submitted to the Kimron Veterinary Institute. These bats exhibited typical poxvirus like lesion plaques of different sizes on the skin, abdomen and the ventral side of the wings. Clinical and histopathological findings suggested a poxvirus infection.

Seroprevalence and Risk Factors for Exposure to Equine Coronavirus in Apparently Healthy Horses in Israel.

Equine coronavirus (ECoV) infection is the cause of an emerging enteric disease of adult horses. Outbreaks have been reported in the USA, EU and Japan, as well as sporadic cases in the UK and Saudi Arabia. Infection of ECoV in horses in Israel has never been reported, and the risk of exposure is unknown.

LL-37-mediated activation of host receptors is critical for defense against group A streptococcal infection.

Group A Streptococcus (GAS) causes diverse human diseases, including life-threatening soft-tissue infections. It is accepted that the human antimicrobial peptide LL-37 protects the host by killing GAS. Here, we show that GAS extracellular protease ScpC N-terminally cleaves LL-37 into two fragments of 8 and 29 amino acids, preserving its bactericidal activity.

Breast cancer colonization by Fusobacterium nucleatum accelerates tumor growth and metastatic progression.

Fusobacterium nucleatum is an oral anaerobe recently found to be prevalent in human colorectal cancer (CRC) where it is associated with poor treatment outcome. In mice, hematogenous F. nucleatum can colonize CRC tissue using its lectin Fap2, which attaches to tumor-displayed Gal-GalNAc.

translocated translation inhibitors are required for bacterial-induced host cell cycle arrest.

The cell cycle machinery controls diverse cellular pathways and is tightly regulated. Misregulation of cell division plays a central role in the pathogenesis of many disease processes. Various microbial pathogens interfere with the cell cycle machinery to promote host cell colonization.

Histones bundle F-actin filaments and affect actin structure.

Histones are small polycationic proteins complexed with DNA located in the cell nucleus. Upon apoptosis they are secreted from the cells and react with extracellular polyanionic compounds. Actin which is a polyanionic protein, is also secreted from necrotic cells and interacts with histones.

Host Cell S Phase Restricts Intracellular Replication by Destabilizing the Membrane-Bound Replication Compartment.

grows within cells ranging from environmental amoebae to human macrophages. In spite of this conserved strategy of pathogenesis, identification of host factors that restrict intracellular replication has not been extended outside components of the mammalian innate immune response. We performed a double-stranded RNA (dsRNA) screen against more than 50% of the annotated open reading frames (ORFs) to identify host cell factors that restrict The majority of analyzed dsRNAs that stimulated intracellular replication were directed against host proteins involved in protein synthesis or cell cycle control.

Interactions of histatin-3 and histatin-5 with actin.

Background: Histatins are histidine rich polypeptides produced in the parotid and submandibular gland and secreted into the saliva. Histatin-3 and -5 are the most important polycationic histatins. They possess antimicrobial activity against fungi such as Candida albicans.

Sustained Release of Antibacterial Lipopeptides from Biodegradable Polymers against Oral Pathogens.

The development of antibacterial drugs to overcome various pathogenic species, which inhabit the oral cavity, faces several challenges, such as salivary flow and enzymatic activity that restrict dosage retention. Owing to their amphipathic nature, antimicrobial peptides (AMPs) serve as the first line of defense of the innate immune system. The ability to synthesize different types of AMPs enables exploitation of their advantages as alternatives to antibiotics.

Actin and DNA Protect Histones from Degradation by Bacterial Proteases but Inhibit Their Antimicrobial Activity.

Histones are small polycationic proteins located in the cell nucleus. Together, DNA and histones are integral constituents of the nucleosomes. Upon apoptosis, necrosis, and infection - induced cell death, histones are released from the cell.

Fap2 Mediates Fusobacterium nucleatum Colorectal Adenocarcinoma Enrichment by Binding to Tumor-Expressed Gal-GalNAc.

Fusobacterium nucleatum is associated with colorectal cancer and promotes colonic tumor formation in preclinical models. However, fusobacteria are core members of the human oral microbiome and less prevalent in the healthy gut, raising questions about how fusobacteria localize to CRC. We identify a host polysaccharide and fusobacterial lectin that explicates fusobacteria abundance in CRC.

Interaction of the core fragments of the LL-37 host defense peptide with actin.

Host defense peptides are effector molecules of the innate immunity that possess antimicrobial and health-promoting properties. Due to their potential therapeutic activities, host defense peptides are being explored as alternatives for antibiotics. The human LL-37 and its shorter, cost-effective, bactericidal core peptide derivates have been suggested for their therapeutic potential.

Streptococcus pyogenes Sortase Mutants Are Highly Susceptible to Killing by Host Factors Due to Aberrant Envelope Physiology.

Cell wall anchored virulence factors are critical for infection and colonization of the host by Gram-positive bacteria. Such proteins have an N-terminal leader sequence and a C-terminal sorting signal, composed of an LPXTG motif, a hydrophobic stretch, and a few positively charged amino acids. The sorting signal halts translocation across the membrane, allowing sortase to cleave the LPXTG motif, leading to surface anchoring.

Biohybrid polymer-antimicrobial peptide medium against Enterococcus faecalis.

Antimicrobial peptides (AMPs) are conserved evolutionary components of the innate immune system that are being tested as alternatives to antibiotics. Slow release of AMPs using biodegradable polymers can be advantageous in maintaining high peptide levels for topical treatment, especially in the oral environment in which dosage retention is challenged by drug dilution with saliva flow and by drug inactivation by salivary enzymatic activity. Enterococcus faecalis is a multidrug resistant nosocomial pathogen and a persistent pathogen in root canal infections.

Actin enables the antimicrobial action of LL-37 peptide in the presence of microbial proteases.

Host defense peptides play an important host-protective role by their microcidal action, immunomodulatory functions, and tissue repair activities. Proteolysis is a common strategy of pathogens used to neutralize host defense peptides. Here, we show that actin, the most abundant structural protein in eukaryotes, binds the LL-37 host defense peptide, protects it from degradation by the proteases of Pseudomonas aeruginosa and Porphyromonas gingivalis, and enables its antimicrobial activity despite the presence of the proteases.

LL-37 opsonizes and inhibits biofilm formation of Aggregatibacter actinomycetemcomitans at subbactericidal concentrations.

Host defense peptides are immediate responders of the innate immunity that express antimicrobial, immunoregulatory, and wound-healing activities. Neutrophils are a major source for oral host defense peptides, and phagocytosis by neutrophils is a major mechanism for bacterial clearance in the gingival tissue. Dysfunction of or reduction in the numbers of neutrophils or deficiency in the LL-37 host defense peptide was each previously linked with proliferation of oral Aggregatibacter actinomycetemcomitans which resulted in an aggressive periodontal disease.

Oxygen deprivation affects the antimicrobial action of LL-37 as determined by microplate real-time kinetic measurements under anaerobic conditions.

Some agents, including Escherichia coli and group A Streptococcus pyogenes cause infections in oxygen depleted sites. LL-37 is a human host defence peptide shown previously to play an important role in controlling infections caused by these bacteria. However, the effect of oxygen levels on the antimicrobial activity of LL-37 remains obscure.

Changes in gene expression of Streptococcus mutans in planktonic environment following CO2 laser irradiation.

Unlabelled: Abstract Objective: The aim of this work was to study the effect of CO2 laser light on gene expression of Streptococcus mutans in a planktonic environment irradiated by sublethal energies.

Background Data: The use of the CO2 laser for oral clinical applications has great benefits over the traditional procedures, including a reduced bacterial environment.

Materials And Methods: In order to determine the sublethal irradiation dose, S.

LL-37 induces polymerization and bundling of actin and affects actin structure.

Actin exists as a monomer (G-actin) which can be polymerized to filaments) F-actin) that under the influence of actin-binding proteins and polycations bundle and contribute to the formation of the cytoskeleton. Bundled actin from lysed cells increases the viscosity of sputum in lungs of cystic fibrosis patients. The human host defense peptide LL-37 was previously shown to induce actin bundling and was thus hypothesized to contribute to the pathogenicity of this disease.