ACS Infectious Diseases最新文献

Inflammasome-mediated pyroptosis and cytokine release are crucial host defenses against intracellular pathogens. Mycobacterium tuberculosis (M. tb) is a successful intracellular pathogen, and it is largely unclear how it evades immune clearance and persists in macrophages. This study investigated whether the Rv2647 protein acts as a key virulence factor of M. tb and explored the potential mechanism of inhibiting macrophage pyroptosis and promoting M. tb survival. The results showed Rv2647 promoted NLRP3 degradation via enhancing its ubiquitination, which led to the inactivation of NLRP3/caspase-1/GSDMD and reduction of IL-1β secretion, thereby inhibiting macrophage pyroptosis and facilitating M. tb survival. Furthermore, Rv2647-mediated enhancement of NLRP3 ubiquitination and degradation depended on its binding to ISG15, competitively inhibiting ISGylation of NLRP3. The study identified Rv2647 as the key virulence factor that promoted M. tb survival by inhibiting macrophage pyroptosis, whose mechanism was to competitively inhibit the ISGylation of NLRP3 and enhance its ubiquitination, thus suppressing NLRP3/caspase-1/GSDMD-mediated pyroptosis. This finding highlighted Rv2647 as a promising drug target or vaccine antigen for tuberculosis prevention and control.

Despite significant advances in human health, soil-transmitted helminths (STH) continue to pose a major public health challenge, particularly in impoverished regions. Albendazole has been used to treat STH for over 40 years and remains widely utilized in mass drug administration programs. However, it is estimated that over 1.5 billion people are still infected globally, with Brazil reporting a prevalence of 5.41% for human trichuriasis. The nematode Trichuris muris is widely used in murine models to study trichuriasis due to its impact on the epithelial mucosa, including tissue damage, dysbiosis, bacterial translocation, inflammatory infiltrate, and intestinal layer hypertrophy. These effects contribute to the more severe consequence of high parasite load infections, such as rectal prolapse. Currently, research on the interaction between intestinal helminths and bacteria remains limited, despite its potential contribution to pathological synergy. Drug resistance in conventional STH treatments is a growing concern, highlighting the need for new therapeutic approaches. This study aimed to evaluate the impact of combining the anthelmintic albendazole with the antibiotics piperacillin sodium plus tazobactam on the inflammatory process during chronic experimental trichuriasis. Swiss Webster mice were infected with 150 embryonated T. muris eggs. After 35 days, the mice were divided into four groups: Group 1 (antibiotic treatment), Group 2 (anthelmintic treatment), Group 3 (combined treatment), and Group 4 (control, no treatment). After treatments, the mice were euthanized, and different analyses were conducted. Results showed that untreated mice had a significantly higher number of peritoneal macrophages compared to those that received treatment. Antibiotic-treated mice did not show invading bacteria in the epithelial submucosa, unlike untreated infected mice. The groups that received anthelmintic treatment exhibited a higher number of dead worms compared to the antibiotic-only group. Additionally, the combination of anthelmintic and antibiotic treatments demonstrated more effective control of nematode colonization and bacterial translocation, potentially reducing the secondary impacts of the infection, such as bacterial translocation and the associated inflammatory processes. These findings suggest that our results could pave the way for the development of new treatment protocols for STH, integrating both anthelmintic and antibiotic therapies.

Antimicrobial resistance (AMR) is rapidly emerging as one of the greatest threats to global health, with projections estimating 10 million deaths annually by 2050. The departure of major pharmaceutical companies from antibiotic research─driven by a combination of scientific complexity, low profitability, and complex regulatory hurdles─has left a serious innovation gap in the development of new antibiotics. This gap is being filled by entrepreneurial ventures in the Global South, particularly in India, South Africa, Brazil, and China, where small and medium enterprises (SMEs) now drive 80% of late-stage antibiotic development. The convergence of abundant scientific talent, cost-effective research capabilities, access to seed funding, and real-world experience with high-burden pathogens is fueling the discovery of innovative solutions to address multidrug-resistant infections. This perspective examines how these vibrant ecosystems are overcoming traditional barriers to innovation by leveraging scientific advancements, tapping into local talent, forming strategic partnerships, and developing novel business models to enable equitable access, thereby realigning public health obligations with commercial viability. This entrepreneurial endeavor in the Global South not only provides sustainable solutions to local health challenges but also contributes to the creation of a resilient global antibiotic ecosystem.

We developed a magnetic affinity probe (MAP), consisting of iron oxide magnetic nanoparticles (MNP) functionalized with a photoaffinity labeling agent perfluorophenyl azide (PFPA), to characterize the internalization of nanoparticles by Mycobacterium smegmatis. Two MAPs were synthesized: a trehalose-functionalized MAP, PFPA-MNP-Tre, and an ethanol-functionalized MAP, PFPA-MNP-OH. Following incubation of MAP with bacteria, the samples were irradiated to trigger covalent bond formation between PFPA and bacterial proteins. The captured proteins were isolated by cleaving the disulfide bond in the linkers and removing the magnetic nanoparticles by using a magnet. For PFPA-MNP-Tre incubated with M. smegmatis for 24 h, proteomic analysis revealed that the captured proteins are cytoplasmic mycobacterial proteins, which provided biochemical evidence for the internalization of nanoparticles in bacteria. Additionally, PFPA-MNP-Tre accumulated at the poles of the mycobacteria, and the amount of captured proteins decreased with increasing concentration of added free trehalose. These results underscore the role the surface ligand plays in modulating the uptake of nanoparticles. The modular MAP platform may find broad applications in studying mechanisms and processes involving nanoparticle–cell interactions.

Since its emergence in late 2019, SARS-CoV-2, the causative agent of COVID-19, has continued to spread globally, with more than 7 million reported deaths as of March 2025. Among the viral nonstructural proteins, nsp12 serves as the RNA-dependent RNA polymerase (RdRp), mediating viral genome replication and transcription in concert with its cofactors nsp7 and nsp8. To date, only two nucleoside analogs specifically targeting SARS-CoV-2 nsp12, remdesivir and molnupiravir, have been authorized by the FDA for COVID-19 treatment. In response to the need for additional safe and effective antiviral agents, we screened two extensive in silico libraries of safe-in-man compounds (>9,000) and natural compounds (>249,000), against the SARS-CoV-2 nsp12/7/8 complex, targeting the orthosteric and two allosteric nsp12 sites, using the EXSCALATE (EXaSCale smArt pLatform Against paThogEns) platform. Compounds were then selected based on docking score significance, novelty for the target, and clinical safety profiles. The top 119 candidates were subsequently evaluated in a biochemical assay to assess their potential to inhibit SARS-CoV-2 nsp12/7/8 polymerase activity, identifying 42 compounds able to block it, among which four showed IC₅₀ and EC₅₀ values in the nanomolar or low micromolar range. When tested in cell-based assays to evaluate their efficacy on SARS-CoV-2 replication, they proved to inhibit it in the same concentration ranges. Mechanism of action studies revealed different modalities of inhibition. These results provide the basis for the development of novel antiviral compounds against SARS-CoV-2, targeting both the RdRp active site and an allosteric site, further suggesting that the Computer-Aided Drug Discovery (CADD) approach, together with experimental validation, can provide the basis for accelerated antiviral drug development.

Nipah (NiV) and Hendra viruses (HeV) have emerged as deadly zoonotic pathogens over the last three decades. Like all paramyxoviruses, Henipaviruses utilize a surface glycoprotein to attach to and invade targeted cells. Inhibiting this attachment glycoprotein is a promising strategy for developing effective antihenipaviral drugs. A multidisciplinary approach has been employed to investigate the structures of HeV and NiV attachment glycoproteins, identifying a flexible region near their binding site. This region, loop 240, can adopt an open conformation in unliganded attachment glycoproteins and a closed “latch” conformation in the presence of their cognate receptor Ephrin B2. Site-directed mutagenesis of the HeV attachment glycoproteins has shown that the engagement of R242 with Ephrin B2 plays an important role in the binding mechanism. This discovery provides greater insight into the dynamic nature of henipaviral attachment proteins and has implications for antiviral drug development.

Dengue remains one of the most important mosquito-borne diseases. Currently, in the absence of targeted antiviral therapy, the treatment of dengue remains supportive. In this study, we found that the neurokinin-1 receptor antagonist fosaprepitant dimeglumine, an FDA-approved drug for the prevention of nausea and vomiting, efficiently inhibited dengue virus (DENV) infection in vitro. Fosaprepitant dimeglumine dose-dependently inhibited DENV replication in several cell lines, including A549 cells and THP-1-derived macrophages, with IC₅₀ values of 3.26 and 4.20 μM, respectively. The time-of-drug-addition and time-of-drug-elimination assays revealed that fosaprepitant dimeglumine acted at late stages after virus entry. Fosaprepitant dimeglumine efficiently inhibited DENV genome replication in a stable reporter DENV-3 replicon cell line. The immune-mediated cytokine storm is known to play a key role in the severe manifestation of dengue. The interferon γ-inducible protein 10 (IP-10) and IL-6 are upregulated in severe dengue. For the first time, we report that fosaprepitant dimeglumine significantly suppressed the levels of the proinflammatory cytokines IL-6 and IP-10 in differentiated THP-1 macrophages infected with DENV-2. Fosaprepitant dimeglumine not only effectively inhibits DENV replication but also attenuates virus-induced inflammatory responses, which makes it a promising candidate for drug repurposing in the treatment of severe dengue.

Leishmaniasis is a neglected tropical disease with limited treatment options and significant unmet medical need. Here, we report the development of a bioluminescence resonance energy transfer (BRET)-based target engagement assay in live cells to identify and validate cell-permeable, ATP-competitive inhibitors of Leishmania mexicana (Lmx)CLK1. LmxCLK2, a closely related paralog with an identical protein kinase domain, is also considered in our analysis. Genetic and pharmacological evidence indicates that simultaneous deletion or inhibition of both LmxCLK1/2 is lethal to the parasite. Using our newly developed assay, we screened a library of human kinase inhibitors and identified WZ8040, a third-generation EGFR inhibitor, as a potent LmxCLK1 ligand. WZ8040 demonstrated robust target engagement in both promastigotes and macrophage-internalized amastigotes, with an EC₅₀ value of 2.1 μM for amastigote killing and minimal toxicity to host macrophages. Biochemical assays confirmed that WZ8040 covalently binds and inhibits LmxCLK1, with mass spectrometry identifying Cys172 as the primary site of modification. Genetic validation using overexpression and knockout lines supports LmxCLK1 as the primary target of WZ8040. However, the retained activity of WZ8040 in mutant lines with the Cys172Ala substitution suggests that covalent binding is not essential for compound efficacy. Our findings highlight the utility of BRET-based assays for target validation in kinetoplastid parasites and underscore the potential of CLK1/2 as druggable kinases in Leishmania. This integrated approach provides a framework for accelerating the discovery of novel antileishmanial agents through target engagement-guided strategies.

Bacterial glycans play a crucial role in survival and pathogenesis, making them attractive antibiotic targets. Unlike mammalian glycans, bacterial glycans incorporate rare sugars such as bacillosamine, N-acetylfucosamine, and 2,4-diacetamido-2,4,6-trideoxy galactose. To probe the role of bacterial glycans, we previously developed O-benzyl glycosides that metabolically inhibit Helicobacter pylori glycan biosynthesis and impair bacterial fitness. Here, we probed the efficacy of O-naphthylmethyl and O-anthracenemethyl glycosides, which bear larger aglycones relative to previously reported bacterial metabolic inhibitors. O-Naphthylmethyl d-N-acetylfucosamine inhibited H. pylori glycan biosynthesis, reduced biofilm formation, and impeded H. pylori growth at lower concentrations than its O-benzyl analog while leaving glycosylation of the commensal bacterium Bacteroides fragilis intact. By contrast, the O-anthracenemethyl glycosides tested were not effective metabolic glycan inhibitors. These metabolic inhibitors expand the bacterial glycoscience toolkit for probing protein glycosylation, help refine metabolic glycan inhibitor design parameters, and have the potential to set the stage for a glycan-based strategy to selectively target pathogens.

The increasing threat of antimicrobial resistance necessitates developing novel strategies to enhance the efficacy of existing antibiotics. This review explores the potential of antimicrobial photodynamic therapy (aPDT) as an adjunctive approach to antibiotic therapy. A systematic literature search was conducted in major scientific databases, focusing on studies published in the past decade investigating the synergistic effects of aPDT with antibiotics. Selected articles were analyzed based on their experimental approaches, bacterial targets, photodynamic parameters, and reported treatment outcomes. aPDT induces bacterial cell damage by generating reactive oxygen species (ROS), enhancing antibiotic susceptibility, and reducing required dosages. Furthermore, the review highlights promising research on optimizing treatment parameters and antibiotic combination strategies to maximize therapeutic outcomes. Despite its potential, aPDT faces obstacles to treatment standardization, variability in bacterial responses, and clinical implementation hurdles. These challenges require standardized protocols, further in vivo studies, and regulatory advancements to integrate aPDT into mainstream antimicrobial therapy. Conclusion: The synergy between aPDT and antibiotics represents a promising frontier in infection control, offering a safer, more effective, and resistance-mitigating strategy for bacterial infections. Future research should focus on refining treatment parameters, assessing long-term clinical impacts, and facilitating the widespread adoption of aPDT as a complementary antimicrobial approach.