ACS Infectious Diseases最新文献

Coinfection of Mycobacterium tuberculosis (Mtb) and human immunodeficiency virus-1 (HIV) is a significant public health concern. Treatment is challenging due to prolonged duration of therapy and drug interactions between antiretroviral therapy (ART) and anti-TB drugs. Noniron gallium meso-tetraphenyl porphyrin (GaTP), a heme mimetic, has shown broad antimicrobial activity. Here, we investigated the efficacy of nanoparticle encapsulating GaTP (GaNP) for the treatment of HIV and Mtb coinfection or single infection in in vitro granuloma structures. GaNP significantly reduced viable Mtb within primary human in vitro granuloma structures infected with Mtb H37Rv-lux and significantly reduced levels of HIV in CD4+ T cells infected with the virus axenically. Similarly, GaNP exhibited significant antimicrobial activity against HIV/Mtb-coinfected granuloma structures created in vitro, which contain the primary immune cells seen in human TB granulomas, including CD4+ T cells and macrophages, as assessed by a luciferase assay for Mtb and p24 ELISA for HIV detection. Furthermore, mechanistic studies revealed that GaTP increases the level of reactive oxygen species and inhibits catalase in Mtb. A significant increase in Mtb nitrate reductase activity was also observed when Mtb was incubated with GaTP and sodium nitrate. Overall, increased oxidative stress and nitrite levels induced by GaTP are consistent with the possibility that GaTP inhibits Mtb aerobic respiration, which leads to incomplete O₂ reduction and a shift to respiration using exogenous NO₃. These cumulative data continue to support the potential for developing the noniron heme analog GaTP and its nanoparticle GaNP as new therapeutic approaches for the treatment of HIV/Mtb coinfection.

Anisakis are foodborne parasites that opportunistically parasitize humans, leading to acute abdominal symptoms and allergies. Besides gastroscopy, no other diagnostic technique is available. Consequently, it is necessary to identify specific biomarkers and then develop molecular techniques for diagnosing Anisakis infection. In the present study, we used immunoproteomic and immunoinformatic approaches to identify sensitive antigens for diagnosing Anisakis pegreffii infection. A total of three proteins, including Ani609 (VDK51609), Ani941 (VDK75941), and AniS13, were identified based on immunoinformatic results. Then, the indirect ELISA method was developed based on the recombinant proteins, showing a similar diagnostic capability to that of parasitic soluble proteins. Next, a Gaussia luciferase immunoprecipitation assay (LIPS) was further developed upon the fusion of the proteins and Gaussia luciferase. The LIPS method indicated that A. pegreffii infection could be detected in rats as early as 1 week post infection, especially for Ani941. Overall, we identified the novel antigens using immunoproteomic and immunoinformatic approaches and then developed a sensitive method for diagnosing A. pegreffii infection, particularly for the early stage.

Polymicrobial wound infections caused by Gram-negative bacteria and associated inflammation are challenging to manage, as many antibiotics do not work against these infections. Utilizing adjuvants to repurpose the existing antibiotics for mitigating microbial infections presents an alternative therapeutic strategy. We designed and developed a niacin-cholic acid-peptide conjugate (1) to rejuvenate the therapeutic efficacy of macrolide antibiotics against Gram-negative pathogens. We conjugated niacin with anti-inflammatory properties at the carboxyl terminal of the cholic acid and dipeptide (glycine-valine) at the three hydroxyl terminals of cholic acid to obtain the amphiphile 1. Our findings demonstrated that amphiphile 1 serves as a microbial membrane disruptor that facilitates the entry of erythromycin (ERY) in bacterial cells. The combination of amphiphile 1 and ERY is bactericidal and can effectively eliminate monomicrobial and polymicrobial Gram-negative bacterial biofilms. We further demonstrated the antibacterial effectiveness of combining 1 and ERY against monomicrobial and polymicrobial wound infections. Together, these findings indicate that amphiphile 1 revitalizes the remedial efficacy of ERY against Gram-negative bacteria.

Mycobacterium tuberculosis is the most ancient human tuberculosis pathogen and has been the leading cause of death from bacterial infectious diseases throughout human history. According to the World Health Organization Global Tuberculosis Report, in 2022, 7.5 million new tuberculosis cases were identified, marking the highest number of cases since the World Health Organization initiated its worldwide tuberculosis surveillance program in 1995. The 2019 peak was 7.1 million cases, with 5.8 million cases in 2020 and 6.4 million in 2021. The increase in 2022, which may be attributed to the COVID-19 pandemic complicating tuberculosis case tracing, has raised concerns. To better understand the regulation spectrum of Mycobacterium smegmatis mraZ under hypoxia, we performed a transcriptome analysis of M. smegmatis mutant and wild-type strains using Illumina Agilent 5300 sequencing. The study identified 6898 differentially expressed genes, which were annotated with NCBI nonredundant protein sequences, a manually annotated and reviewed protein sequence database, Pfam, Clusters of Orthologous Groups of Proteins, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes. Several mycobacteria transcriptional regulators, virulence genes, membrane transporters, and cell wall biosynthesis genes were annotated. These data serve as a valuable resource for future investigations and may offer insight into the development of drugs to combat M. tuberculosis infection.

Enteroviruses cause significant morbidity and mortality worldwide, and Coxsackievirus B3 (CVB3) is one of the most commonly reported. Coxsackieviruses establish persistent infection, characterized as infection that is not cleared from host cells generating a continuous infection. No antivirals targeting persistent or acute infection are available, and CVB3 may respond differently depending on the type of infection. Therefore, there is an urgent need for new antiviral drugs to combat acute and persistent CVB3 infection. We developed a system to study persistent CVB3 infection with pancreatic ductal cell line PANC-1, and we used an epithelial cell line, Vero-E6 cells, to study acute CVB3 infection. We maintained persistently infected cells for over a year. Now, in an effort to identify antivirals, using the National Institutes of Health's Developmental Therapeutics Program (DTP), we screened thousands of compounds for activity against acute and persistent CVB3 infection, and among the hits was Ro 5-3335, a 1,4-benzodiazepine nordazepam that acts as a RUNX1-CBFβ leukemia inhibitor. Ro 5-3335 has previously been reported to inhibit HIV-1 gene expression through interference with Tat-mediated transactivation. We confirmed Ro 5-3335's antiviral activity against CVB3 in both acute and persistent infection, in several cell types and at pharmacologically favorable conditions. We show that Ro 5-3335 has minimal cytotoxicity and is antiviral over several rounds of replication. We identified viral egress as a putative target. We also show efficacy against other RNA viruses, but it is ineffective against a model DNA virus. Overall, Ro 5-3335 is a promising antiviral that may target CVB3 infection.

Fascioliasis, a zoonotic disease caused by liver flukes of the genus Fasciola, poses significant health threats to both humans and livestock. While some infections remain asymptomatic, others can lead to fatal outcomes, particularly during the acute phase characterized by the migration of immature parasites causing severe liver damage. Through the combination of data acquired via high-spatial-resolution atmospheric-pressure scanning microprobe matrix-assisted laser desorption/ionization mass spectrometry imaging (AP-SMALDI MSI) and nanohydrophilic interaction chromatography tandem mass spectrometry, we investigated glycosphingolipids (GSLs) in both adult and immature parasite stages as well as the host liver and bile duct to unravel the intricacies of the host-pathogen interplay and associated pathology. Several GSLs showed characteristic distribution patterns within the parasite depending on the fatty acid composition of their ceramides, notably including GSLs carrying very long-chain fatty acids. Additionally, GSL compositions within the tegument of immature versus adult parasites varied, suggestive of tissue remodeling upon maturation. AP-SMALDI MSI further enabled the identification of GSLs potentially involved in in vivo interactions between the host and immature parasites. Moreover, our experiments unveiled alterations in other lipid classes during Fasciola infection, providing a broader understanding of lipidomic changes associated with the disease. Collectively, our findings contribute to a deeper comprehension of the molecular intricacies underlying fascioliasis, with a specific focus on GSLs.

Pseudomonas aeruginosa is a leading bacterial pathogen that causes persistent infections. One major reason that antibiotics fail to clear such infections is the presence of a dormant subpopulation called persister cells. To eradicate persister cells, it is important to change drug development from traditional strategies that focus on growth inhibition to the search for new leads that can kill dormant cells. In this study, we demonstrate that eravacycline can effectively accumulate in P. aeruginosa persister cells, leading to strong killing during wakeup, including persister cells in both planktonic cultures and biofilms of the wild-type strain and its mucoid mutant. The effects of eravacycline on persister control were further validated in vivo using a lung infection model in mice. Collectively, these results demonstrate the possibility to control persister cells of bacterial pathogens by targeting dormancy.

Chronic Chagas cardiomyopathy is associated with an unbalanced immune response and impaired heart function, and available drugs do not prevent its development. Zileuton (Zi), a 5-lypoxigenase inhibitor, affects inflammatory/pro-resolution mediators. Herein, Zi treatment in the early phase of infection reduced parasitemia associated mainly with the direct effect of Zi on the parasite, and the enzyme epoxide hydrolase was the potential molecular target behind the trypanocidal effect. In the intermediate acute phase of infection, Zi reduced the number of innate and adaptive inflammatory cells, increased the level of SOCS2 expression in the heart associated with lower inflammation, and improved cardiac function. Zi treatment initiated in the chronic stage increased the level of SOCS2 expression in the heart, reduced inflammation, and improved cardiac function. Our data suggest that Zi protects against Trypanosoma cruzi infection by acting directly on the parasite and reducing heart damage and is a promising option for the treatment of Chagas disease.

To combat the rise of antibiotic-resistance in bacteria and the resulting effects on healthcare worldwide, new technologies are needed that can perform rapid antibiotic susceptibility testing (AST). Conventional clinical methods for AST rely on growth-based assays, which typically require long incubation times to obtain quantitative results, representing a major bottleneck in the determination of the optimal antibiotic regimen to treat patients. Here, we demonstrate a rapid AST method based on the metabolic activity measured by fluorescence lifetime imaging microscopy (FLIM). Using lab strains and clinical isolates of Escherichia coli with tetracycline-susceptible and resistant phenotypes as models, we demonstrate that changes in metabolic state associated with antibiotic susceptibility can be quantitatively tracked by FLIM. Our results show that the magnitude of metabolic perturbation resulting from antibiotic activity correlates with susceptibility evaluated by conventional metrics. Moreover, susceptible and resistant phenotypes can be differentiated in as short as 10 min after antibiotic exposure. This FLIM-AST (FAST) method can be applied to other antibiotics and provides insights into the nature of metabolic perturbations inside bacterial cells resulting from antibiotic exposure with single cell resolution.

Antibiotic resistance in bacteria is a major global health concern. The wide spread of carbapenemases, bacterial enzymes that degrade the last-resort carbapenem antibiotics, is responsible for multidrug resistance in bacterial pathogens and has further significantly exacerbated this problem. Acinetobacter baumannii is one of the leading nosocomial pathogens due to the acquisition and wide dissemination of carbapenem-hydrolyzing class D β-lactamases, which have dramatically diminished available therapeutic options. Thus, new antibiotics that are active against multidrug-resistantA. baumannii and carbapenemase inhibitors are urgently needed. Here we report characterization of the interaction of the C5α-methyl-substituted carbapenem NA-1-157 with one of the clinically important class D carbapenemases, OXA-58. Antibiotic susceptibility testing shows that the compound is more potent than commercial carbapenems against OXA-58-producingA. baumannii, with a clinically sensitive MIC value of 1 μg/mL. Kinetic studies demonstrate that NA-1-157 is a very poor substrate of the enzyme due mainly to a significantly reduced deacylation rate. Mass spectrometry analysis shows that inhibition of OXA-58 by NA-1-157 proceeds through both the classical acyl-enzyme intermediate and a reversible covalent species. Time-resolved X-ray crystallographic studies reveal that upon acylation of the enzyme, the compound causes progressive decarboxylation of the catalytic lysine residue, thus severely impairing deacylation. Overall, this study demonstrates that the carbapenem NA-1-157 is highly resistant to degradation by the OXA-58 carbapenemase.