Orally available nucleoside analog UMM-766 provides protection in a murine model of orthopox disease.

Although smallpox has been eradicated, other orthopoxviruses continue to be a public health concern as exemplified by the ongoing Mpox (formerly monkeypox) global outbreak. While medical countermeasures (MCMs) previously approved by the Food and Drug Administration for the treatment of smallpox have been adopted for Mpox, previously described vulnerabilities coupled with the questionable benefit of at least one of the therapeutics during the 2022 Mpox outbreak reinforce the need for identifying and developing other MCMs against orthopoxviruses. Here, we screened a panel of Merck proprietary small molecules and identified a novel nucleoside inhibitor with potent broad-spectrum antiviral activity against multiple orthopoxviruses.

Modification of N-hydroxycytidine yields a novel lead compound exhibiting activity against the Venezuelan equine encephalitis virus.

Nucleoside and nucleobase analogs capable of interfering with nucleic acid synthesis have played essential roles in fighting infectious diseases. However, many of these agents are associated with important and potentially lethal off-target intracellular effects that limit their use. Based on the previous discovery of base-modified 2'-deoxyuridines, which showed high anticancer activity while exhibiting lower toxicity toward rapidly dividing normal human cells compared to antimetabolite chemotherapeutics, we hypothesized that a similar modification of the N-hydroxycytidine (NHC) molecule would provide novel antiviral compounds with diminished side effects.

A Novel Toll-Like Receptor 2 Agonist Protects Mice in a Prophylactic Treatment Model Against Challenge With .

Current therapies for anthrax include the use of antibiotics (i.e., doxycycline, and ciprofloxacin), an anthrax vaccine (BioThrax) and -specific, monoclonal antibody (mAb) (i.

Screening of a Focused Ubiquitin-Proteasome Pathway Inhibitor Library Identifies Small Molecules as Novel Modulators of Botulinum Neurotoxin Type A Toxicity.

Botulinum neurotoxins (BoNTs) are known as the most potent bacterial toxins, which can cause potentially deadly disease botulism. BoNT Serotype A (BoNT/A) is the most studied serotype as it is responsible for most human botulism cases, and its formulations are extensively utilized in clinics for therapeutic and cosmetic applications. BoNT/A has the longest-lasting effect in neurons compared to other serotypes, and there has been high interest in understanding how BoNT/A manages to escape protein degradation machinery in neurons for months.

In vitro and in vivo activity of GT-1, a novel siderophore cephalosporin, and GT-055, a broad-spectrum β-lactamase inhibitor, against biothreat and ESKAPE pathogens.

Antimicrobial-resistance (AMR) has become an increasingly difficult issue to overcome for bacteria associated with both community- and hospital-acquired infections as well as potential biodefense threats. The need to identify new therapeutics of novel classes and/or with unique mechanisms is critical to combatting AMR in the coming years. GT-1 (LCB10-0200), a siderophore-linked cephalosporin, is one such novel option and is formulated to be used either alone or in combination with a novel broad-spectrum β-lactamase inhibitor, GT-055 (LCB18-055).

A direct spectropolarimetric assay of arabinose 5-phosphate isomerase.

Arabinose 5-phosphate isomerase (API) catalyzes the reversible isomerization of Ribulose 5-phosphate (Ru5P) to Arabinose 5-Phosphate (Ar5P) for the production of 3-deoxy-2-octulosonic acid 8-phosphate (KDO), a component of bacterial lipopolysaccharide (LPS) of gram-negative bacteria. API is an attractive target for therapeutic development against gram-negative bacterial pathogens. The current assay method of API activity utilizes a general reaction for keto sugar determination in a secondary, 3-h color development reaction with 25 N sulfuric acid which poses hazard to both personnel and instrumentation.

Combinations of early generation antibiotics and antimicrobial peptides are effective against a broad spectrum of bacterial biothreat agents.

The misuse of infectious disease pathogens as agents of deliberate attack on civilians and military personnel is a serious national security concern, which is exacerbated by the emergence of natural or genetically engineered multidrug resistant strains. In this study, the therapeutic potential of combinations of an antibiotic and a broad-spectrum antimicrobial peptide (AMP) was evaluated against five bacterial biothreats, the etiologic agents of glanders (Burkholderia mallei), melioidosis (Burkholderia pseudomallei), plague (Yersinia pestis), tularemia (Francisella tularensis), and anthrax (Bacillus anthracis). The therapeutics included licensed early generation antibiotics which are now rarely used.

Development of a Coxiella burnetii culture method for high-throughput assay to identify host-directed therapeutics.

The intracellular Gram-negative bacterium, Coxiella burnetii, is a worldwide zoonotic pathogen and the causative agent of Q fever. The standard of care for C. burnetii infections involves extended periods of antibiotic treatment and the development of doxycycline-resistant strains stress the need for new treatment strategies.

Enhancing the antibacterial activity of polymyxins using a nonantibiotic drug.

The rapid emergence of multidrug-resistant (MDR) bacteria and the lack of new therapies to eliminate them poses a major threat to global health. With the alarming rise in antimicrobial resistance (AMR), focus has now shifted to the use of the polymyxin class of antibiotics as the last line of defense for treatment of Gram-negative infections. Unfortunately, the growing resistance of bacteria against polymyxins is threatening the treatment of MDR infections, necessitating the need for novel strategies.

Aminomethyl spectinomycins: a novel antibacterial chemotype for biothreat pathogens.

New antibiotics that are active against multi-drug-resistant strains and difficult-to-treat bacterial infections are needed. Synthetic modification of spectinomycin, a bacterial protein synthesis inhibitor, has been shown to increase antibacterial activity compared with spectinomycin. Aminomethyl spectinomycins are active against Gram-negative and Gram-positive bacterial pathogens.

Robust biofilm assay for quantification and high throughput screening applications.

Bacterial biofilms are populations of bacteria within a self-produced adherent extracellular matrix that are notoriously resistant to treatment. Existing methods for biofilm quantification are often limited in their dynamic range of detection (signal-to-background), throughput, and require modifications to the protocol depending on the bacterial species. To address these limitations, a broad utility, high-throughput (HTP) method was required.

Characterization of the plasma proteome of nonhuman primates during Ebola virus disease or melioidosis: a host response comparison.

Background: In-depth examination of the plasma proteomic response to infection with a wide variety of pathogens can assist in the development of new diagnostic paradigms, while providing insight into the interdependent pathogenic processes which encompass a host's immunological and physiological responses. Ebola virus (EBOV) causes a highly lethal infection termed Ebola virus disease (EVD) in primates and humans. The Gram negative non-spore forming bacillus () causes melioidosis in primates and humans, characterized by severe pneumonia with high mortality.

The Biophysical Interaction of the Danger-Associated Molecular Pattern (DAMP) Calreticulin with the Pattern-Associated Molecular Pattern (PAMP) Lipopolysaccharide.

The endoplasmic reticulum (ER) chaperone protein, calreticulin (CRT), is essential for proper glycoprotein folding and maintaining cellular calcium homeostasis. During ER stress, CRT is overexpressed as part of the unfolded protein response (UPR). In addition, CRT can be released as a damage-associated molecular pattern (DAMP) molecule that may interact with pathogen-associated molecular patterns (PAMPs) during the innate immune response.

Second generation of diazachrysenes: Protection of Ebola virus infected mice and mechanism of action.

Ebola virus (EBOV) causes a deadly hemorrhagic fever in humans and non-human primates. There is currently no FDA-approved vaccine or medication to counter this disease. Here, we report on the design, synthesis and anti-viral activities of two classes of compounds which show high potency against EBOV in both in vitro cell culture assays and in vivo mouse models Ebola viral disease.

Bioengineering of bacterial pathogens for noninvasive imaging and in vivo evaluation of therapeutics.

Critical bacterial pathogens of public health and biodefense concerns were engineered to constitutively express Escherichia coli enzyme thymidine kinase (TK) that allows for noninvasive nuclear imaging via phosphorylation and entrapment of radiolabeled nucleoside analog 1-(2'deoxy-2'-fluoro-β-D-arabinofuranosyl)-5-iodouracil (FIAU). Expression of functional TK was established using a nucleoside analog Zidovudine that impeded the growth of tk-engineered bacteria. Significantly, no observable growth differences were detected for FIAU.

Mitigating the Impact of Antibacterial Drug Resistance through Host-Directed Therapies: Current Progress, Outlook, and Challenges.

Increasing incidences of multidrug resistance in pathogenic bacteria threaten our ability to treat and manage bacterial infection. The development and FDA approval of novel antibiotics have slowed over the past decade; therefore, the adoption and improvement of alternative therapeutic strategies are critical for addressing the threat posed by multidrug-resistant bacteria. Host-directed therapies utilize small-molecule drugs and proteins to alter the host response to pathogen infection.

Bacterial genome engineering and synthetic biology: combating pathogens.

Background: The emergence and prevalence of multidrug resistant (MDR) pathogenic bacteria poses a serious threat to human and animal health globally. Nosocomial infections and common ailments such as pneumonia, wound, urinary tract, and bloodstream infections are becoming more challenging to treat due to the rapid spread of MDR pathogenic bacteria. According to recent reports by the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC), there is an unprecedented increase in the occurrence of MDR infections worldwide.

Biochip for the Detection of Bacillus anthracis Lethal Factor and Therapeutic Agents against Anthrax Toxins.

Tethered lipid bilayer membranes (tBLMs) have been used in many applications, including biosensing and membrane protein structure studies. This report describes a biosensor for anthrax toxins that was fabricated through the self-assembly of a tBLM with B. anthracis protective antigen ion channels that are both the recognition element and electrochemical transducer.

L1000CDS: LINCS L1000 characteristic direction signatures search engine.

The library of integrated network-based cellular signatures (LINCS) L1000 data set currently comprises of over a million gene expression profiles of chemically perturbed human cell lines. Through unique several intrinsic and extrinsic benchmarking schemes, we demonstrate that processing the L1000 data with the characteristic direction (CD) method significantly improves signal to noise compared with the MODZ method currently used to compute L1000 signatures. The CD processed L1000 signatures are served through a state-of-the-art web-based search engine application called L1000CDS.

Characterization of the murine macrophage response to infection with virulent and avirulent Burkholderia species.

Background: Burkholderia pseudomallei (Bp) and Burkholderia mallei (Bm) are Gram-negative facultative intracellular pathogens, which are the causative agents of melioidosis and glanders, respectively. Depending on the route of exposure, aerosol or transcutaneous, infection by Bp or Bm can result in an extensive range of disease - from acute to chronic, relapsing illness to fatal septicemia. Both diseases are associated with difficult diagnosis and high fatality rates.

A reverse-phase protein microarray-based screen identifies host signaling dynamics upon Burkholderia spp. infection.

Burkholderia is a diverse genus of gram-negative bacteria that causes high mortality rate in humans, equines and cattle. The lack of effective therapeutic treatments poses serious public health threats. Developing insights toward host-Burkholderia spp.

Evaluation of Ebola Virus Inhibitors for Drug Repurposing.

A systematic screen of FDA-approved drugs was performed to identify compounds with in vitro antiviral activities against Ebola virus (EBOV). Compounds active (>50% viral inhibition and <30% cellular toxicity) at a single concentration were tested in dose-response assays to quantitate the antiviral activities in replication and viral entry assays as well as cytotoxicity in the Vero cell line used to conduct these assays. On the basis of the approved human dosing, toxicity/tolerability, and pharmacokinetic data, seven of these in vitro hits from different pharmacological classes (chloroquine (CQ), amiodarone, prochlorperazine, benztropine, azithromycin, chlortetracycline, and clomiphene) were evaluated for their in vivo efficacy at a single dose and were administered via either intraperitoneal (ip) or oral route.