Background The relationship between Streptococcus pyogenes (Group A Streptococcus) and COVID‐19 has been of interest because of possible coinfections and their clinical implications. This discussion examines the interaction between these pathogens and focuses on rates of coinfection, effects, and diagnostic considerations. Materials and Methods This study on 119 COVID‐19 patients involved sampling pharyngeal and nasal secretions for streptococcal culture and PCR testing. RNA extraction, cDNA synthesis, and RT‐qPCR targeted the N gene of SARS‐CoV‐2. Results This study on 119 COVID‐19 patients revealed a prevalence of 52.94%, with higher rates among women and older individuals. Streptococcal infection prevalence was 34.45%, significantly elevated in COVID‐19 patients compared with noninfected individuals ( p < 0.001). Notably, streptococcal infection rates were higher in men, older age groups, and those exhibiting symptoms like shortness of breath, cough, fever, weakness, and lethargy ( p < 0.001). Conclusion The co‐occurrence of S . pyogenes infections with COVID‐19 complicates diagnosis, necessitating comprehensive laboratory testing. Understanding their epidemiology informs public health strategies for surveillance, prevention, and control, highlighting the complexities in infectious disease management.
Plasmodium infects hepatocytes prior to establishing a pathogenic blood stage infection. During liver stage development, parasites modulate their host cells to survive, grow, and multiply, resulting in the formation of merozoites that are released into the blood stream. Compared with the number of parasite proteins that are exported into the erythrocyte, evidence exists for the export of only a very few parasite proteins into the host hepatocyte. Here, we screened multiple Plasmodium berghei candidate proteins for liver stage expression and export into the hepatocyte. To ascertain expression and export, proteins were tagged with either mCherry or 3xcMyc. This screening resulted in the identification of a novel liver stage exported protein, that is, LSEP. Although LSEP fused to mCherry failed to translocate into the hepatocyte, cMyc-tagged LSEP was exported into the hepatocyte cytosol, indicating that the tag structure or size influences export into the hepatocyte. In addition, the known liver stage-specific and exported protein LISP2 was tagged with mCherry/cMyc in multiple locations (N-terminal, internal, and C-terminal). Notably, only LISP2 tagged with cMyc at its N-terminus translocated into the hepatocyte, showing that both the choice of the tag and the location of the tag are important for identifying proteins that are exported into the hepatocyte cytosol. Identifying novel exported proteins may, in turn, lead to the identification of potential targets for possible therapeutics.
Porphyromonas gulae has been established as a pathogen in animal periodontal disease and expresses several virulence factors, including fimbriae, lipopolysaccharide, and proteases. P. gulae fimbriae are classified into three genotypes (A, B, and C) based on the fimbrillin (fimA) gene encoding a fimbrial subunit protein. We previously reported that P. gulae organisms with type C fimbriae were clearly more virulent as compared to those with other fimbria types, though the basic function of this is not fully understood. Here, we investigated the function of fimbriae using fimA-deficient mutants. In the present study, bacterial fimbriae were related to biofilm tenacity, whereas biofilm formation was not. Also, P. gulae fimbriae are involved in bacterial adhesion and entry into gingival epithelial cells. The role of P. gulae fimbriae in bacterial pathogenicity was then determined using fimA-deficient mutants with a silkworm infection model. Additionally, P. gulae infection can induce inflammatory responses in gingival epithelial cells and also inhibit cell migration and proliferation. In contrast, a P. gulae fimA-deficient mutant did not cause several of those cellular responses. Together, the results show that fimbriae contribute to the pathogenicity of P. gulae by affecting bacterial functions and host cell interactions.
Candida albicans (C. albicans) is an opportunistic yeast that forms biofilms, which confer increased resistance to antifungal agents, making infections very difficult to treat. One of the mechanisms regulating this virulence is quorum sensing (QS), which can be defined as a cellular communication mechanism based on the production of autoinducer, namely, farnesol. We previously reported that the essential oils of Cistus ladanifer, Matricaria chamomilla, and Pistacia lentiscus inhibit C. albicans. In this context, a virtual screening of 48 molecules derived from these plants, as well as their ADMET property predictions, was undertaken to identify the most promising ligands for inhibiting QS receptors (CYC and RAS1) compared to farnesol. The latter exhibited a binding affinity of -7.0 kcal/mol for both CYC and RAS1. Two phytomolecules, namely, chamazulene and gamma-muurolene, exhibited stronger binding affinities of -7.6 and -8.1 kcal/mol, respectively, for CYC, while toward the RAS1 receptor, they showed identical binding affinities of -7.1 kcal/mol. According to the binding free energy calculations performed using Prime MM-GBSA, the complexes formed by gamma-muurolene exhibited high stability, maintained by coulombic, lipophilic, and Van der Waals interactions, demonstrating that gamma-muurolene is a promising inhibitor of QS. Molecular dynamic simulations confirmed the conformational stability of the CYC-gamma-muurolene and RAS1-gamma-muurolene complexes, characterized by low RMSD values, suggesting favorable dynamic behavior. The results as a whole provide a solid foundation for further experimental validation.
Candida albicans is a commensal fungus of the vaginal and reproductive tract microbiota, but its overgrowth contributes to mucosal infections and reproductive dysfunctions. The fungus secretes exosomes carrying virulence factors, including secreted aspartyl proteinase (SAP) genes, which are critical for tissue invasion and immune modulation. Acarbose, an alpha-glucosidase inhibitor, has been shown to suppress C. albicans biofilm formation and hyphal transition. This study is aimed at evaluating the effects of acarbose on the ovarian microbiota, gut-ovary axis, and SAP gene expression profile in a rat model following exposure to C. albicans exosomes. Rats were divided into two groups: the control group received intraperitoneal C. albicans exosomes (8 log(10) CFU/mL), whereas the acarbose group received the same exosomes followed by oral acarbose (25 mg/kg/day). Exosomes were characterized by NTA and SEM. Ovarian tissue gene expression (SAP1-10) was analyzed by qRT-PCR. Inflammatory cytokines and tight junction proteins were assessed via ELISA, and microbiota composition was determined using 16S rRNA sequencing. Acarbose significantly reduced IL-8 and TNF-alpha levels while increasing IL-10, ZO-1, claudin-5, and occludin expression compared with Candida-infected controls (p < 0.05). Gut microbiota diversity and classification success were higher in the acarbose group, indicating microbial balance restoration. Acarbose mitigated C. albicans exosome-induced inflammation and barrier dysfunction while enhancing microbial diversity, suggesting its potential role in modulating the ovarian-gut axis and reducing fungal virulence through SAP gene suppression.
Nonpathogenic microorganisms confer various health benefits, including potential anticancer activity. Lactobacillus strains may influence tumor cell fate through immune modulation and microbial metabolites, with potential effects on apoptosis-related signaling networks. In this study, the cytotoxic/antiproliferative activity of cell-free supernatants (CFSs) from Lactobacillus fermentum PTCC 1744 and Lactobacillus casei PTCC 1608 was investigated in human gastric adenocarcinoma (AGS) cells. AGS cells were treated with graded concentrations of CFS for 24, 48, and 72 h, and cell viability/metabolic activity was assessed using the MTT assay. Based on the maximal cytotoxic effect, 12.5% CFS was selected for qRT-PCR. At 72 h, qRT-PCR was performed to evaluate the expression of apoptosis-related genes (BCL2, PTEN, AKT1, and BAX), with GAPDH as the normalizer. Both CFSs induced a time-dependent reduction in MTT signal; however, no linear concentration-response relationship was observed, and lower concentrations showed a stimulatory pattern. Gene expression analysis revealed strain-specific transcriptional responses: L. casei CFS was associated with upregulation of BCL2 and downregulation of PTEN, AKT1, and BAX, whereas L. fermentum CFS was associated with marked upregulation of PTEN and downregulation of BCL2, AKT1, and BAX. Collectively, these findings suggest strain-specific cytotoxic/antiproliferative activity and differential modulation of apoptosis-related gene expression in AGS cells, with L. fermentum showing a transcriptional profile more consistent with attenuation of PI3K/Akt-associated survival signaling under the tested conditions. Further studies using orthogonal assays are needed to confirm the mechanisms of cell death.
(-)-Globulol is a sesquiterpenoid with a variety of biological activities such as antifungal, antiparasitic, and anticomplexinase. However, the potential antibacterial properties of (-)-globulol remain uncertain. Here, the antibacterial effects of (-)-globulol against Staphylococcus aureus (S. aureus) were evaluated by assays of bacterial growth profiles, cell surface hydrophobicity (CSH), and growth phenomenon of bacteria in the liquid culture medium, cellular microstructure, permeability of cell envelopes, and liquid chromatography-mass spectrometer (LC-MS) nontargeted metabolomics. The result of the bacterial growth assay showed that the minimum inhibitory concentration (MIC) value of (-)-globulol against S. aureus was 7.81 mu g/mL. When exposed to (-)-globulol, dose-dependent aggregation of S. aureus was observed, triggered by increased CSH, disruption of the cell envelope, and cell wall integrity. Metabolomic analysis exhibited fluctuations in metabolites associated with S. aureus cell membranes, such as upregulation of N-acetyl glutamic acid and biotin and downregulation of cytidine diphosphoglycerol and D-glucaric acid, indicating their inhibition. Simultaneously, cell wall synthesis was also disrupted by the upregulation of L-tryptophan and palmitoleic acid. In summary, we confirm that cell membrane disruption by (-)-globulol plays a key role in its antimicrobial activity.
The morphological transition of Candida spp. is a key virulence factor that enables these fungi to cause infections in humans. This ability to shift between yeast-like, hyphal, and pseudohyphal forms allows Candida species to adapt to diverse environments and hostile conditions, playing a critical role in pathogenicity. In this study, we investigated the effects of synthetic chalcones on the morphological transition of Candida albicans and Candida tropicalis, alongside an in silico evaluation of the compounds' pharmacokinetic properties, including absorption, distribution, metabolism, excretion, and toxicity (ADMET). To assess the inhibitory effects of chalcones and fluconazole on morphological transition, humid chambers were prepared and analyzed through optical microscopy. The predictions were performed using MarvinSketch (ChemAxon method), pkCSM, SMARTCyp, and Pred-Skin 3.0 platforms. The chalcones (1E,4E)-1,5-diphenylpenta-1,4-dien-3-one (DB-Acetone), (1E,3E,6E,8E)-1,9-diphenylnona-1,3,6,8-tetraen-5-one (DB-CNM), and (1E,4E)-1,5-bis (4-methoxyphenyl)penta-1,4-dien-3-one (DB-Anisal), as well as fluconazole, completely inhibited fungal morphological transition at the tested concentrations (MC, 1024 mu g/mL, and MC/2, 512 mu g/mL). In silico analyses revealed high intestinal absorption for all chalcones, with DB-Acetone and DB-Anisal showing potential for significant oral bioavailability. Moreover, all compounds demonstrated extensive tissue distribution and the ability to cross the blood-brain barrier. Despite some limitations, DB-Acetone, DB-CNM, and DB-Anisal were predicted to be well tolerated at high doses, with DB-Anisal emerging as the safest candidate based on toxicity profiles. Overall, these findings suggest that the synthetic chalcones studied are promising agents for inhibiting the morphological transition of C. albicans and C. tropicalis, with DB-Anisal showing the most favorable pharmacokinetic and safety profile.
Extracellular vesicles (EVs) are nanovesicles secreted by cells with lipid bilayer structure, which play a key role in the communication between bacteria and host cells. This paper reviews the role of EVs, particularly bacterial‐derived EVs (bEVs) and host cell (e.g., macrophage)‐derived exosomes, in the regulation of macrophage polarization during bacterial infection. Macrophages can differentiate into M1 and M2 types with different functions, which is very important in the innate immune response. bEVs and exosomes influence the polarization state of macrophages by carrying a variety of bioactive molecules, such as bacterial effectors, nucleic acids, and lipids, and finally, they are involved in the regulation of host immune and inflammatory responses. In addition, EVs show great potential in early disease diagnosis, vaccine development, and targeted therapy. However, the application of EVs still faces many challenges, including the development of isolation and purification techniques, the establishment of standardized processes, and the clarity of specific mechanisms. In this review, the mechanism of bEVs and exosomes in regulating macrophage polarization is systematically summarized, their potential applications in infectious diseases are explored, and directions for future research are proposed. With a deeper understanding of the function and regulatory mechanisms, EVs are expected to become a new diagnostic marker and a therapeutic tool, providing new strategies for the prevention and treatment of infectious diseases.
Objective: The objective of the study is to investigate the epidemiological characteristics of Mycoplasma pneumoniae (MP) infection in the central region of Inner Mongolia from November 2023 to October 2024 and to provide evidence for the effective prevention and control of MP infections. Methods: A cross-sectional study design was employed, retrospectively including patients from the People ' s Hospital of Inner Mongolia Autonomous Region who underwent both MP nucleic acid (MP-DNA) testing and MP-IgM antibody testing during the same period. Chi-square tests were used to compare the positive rates among different sexes, age groups, and seasons. McNemar ' s test was applied to evaluate the differences in positive rates between the two methods, and kappa values were used to assess the consistency between the two detection methods. During the study period, 19,330 MP-DNA tests and 15,335 MP-IgM tests were conducted. There was no statistically significant difference in the positive rate of MP-DNA between males and females (28.37% vs. 29.18%, p > 0.05), but there was a significant difference in the positive rate of MP-IgM (18.41% vs. 21.07%, p < 0.001). The highest positive rates were observed in the pediatric group (0-17 years old) for both MP-DNA (34.77%) and MP-IgM (24.23%). Overall, the positive rates differed significantly among the age groups (MP-DNA chi(2) = 1215.31, p < 0.001; MP-IgM chi(2) = 725.42, p < 0.001). Seasonal analysis revealed that the highest positive rates for both MP-DNA and MP-IgM occurred in autumn (August to October) (36.45% vs. 28.23%). The highest positive detection rates for both MP-DNA and MP-IgM were found in patients diagnosed with lower respiratory tract infections. Analysis of 3140 subjects who underwent both nucleic acid and antibody testing revealed a statistically significant difference in positive rates between the two methods (p < 0.001), but the consistency level was low (kappa = 0.26). Conclusion: The results indicate that MP infection is prevalent among children and peaks in autumn. The low consistency between the MP-DNA and MP-IgM detection methods underscores the importance of combined diagnostic approaches. This study highlights the need for targeted disease surveillance and preventive measures on the basis of demographic and seasonal characteristics in the region.
Research on Fusarium oxysporum f. sp. lini (Foln), a fungal pathogen of Linum usitatissimum L. (flax) responsible for significant crop losses, requires effective methods for visualizing fungus-plant interactions to improve understanding of this pathosystem. In this study, transgenic Foln strains expressing GFP or dsRed fluorescent markers were generated via Agrobacterium-mediated transformation. Several Agrobacterium tumefaciens strains were tested, and those with the highest transformation efficiency were selected. Transformants were screened based on phenotypic characteristics and further validated using molecular biology techniques. Since transgenesis can influence a fungus ' s ability to infect its host, the pathogenicity of the generated Foln lines was assessed by measuring the expression levels of pathogenesis-related genes and ROS metabolism-related genes, alongside quantifying O2- and H2O2 levels in the infected plant tissue. The presence of dsRed and GFP fluorescent markers was confirmed using fluorescence microscopy. Ultimately, two transformants exhibiting pathogenic characteristics similar to the wild-type Foln strain were selected. These transformants represent valuable tools for further studies of Foln pathogenesis in flax. Additionally, the workflow developed here can be adapted to generate fluorescent transformants of other F. oxysporum pathogenic strains.
AimsPorphyromonas gingivalis is a keystone pathogen in periodontitis that releases bacterial extracellular vesicles (bEVs) with a content derived from the membrane and cytosol of the bacteria itself. The bEVs are taken up by host tissue cells, such as oral fibroblasts, yet their effects on human cells remain incompletely understood.MethodsThe aim of this study was to investigate the impact of bEVs on human oral fibroblasts. Targeted liquid chromatography-mass spectrometry was used to assess changes in the metabolome of these cells following exposure to bEVs from three strains of P. gingivalis (ATCC 33277, A7A1-28, and W83). Metabolite content of the bEVs from each strain was also characterized.ResultMetabolomic analyses revealed both common and strain-specific metabolites in the bEVs from these strains. Additionally, pathways mainly associated with amino acid metabolism were enriched for all. Following exposure to bEVs, the fibroblasts exhibited a metabolic shift in energy metabolism. In particular, fibroblasts incubated with bEVs from ATCC 33277 had a unique profile of enriched pathways after 10 min. However, after 24 h, this profile changed and became more similar to the profile in fibroblasts incubated with bEVs from the two more pathogenic strains. Pathway analysis revealed enrichment of glycerophospholipid and butanoate metabolism for fibroblasts exposed to all the bEVs. Additionally, altered sphingolipid metabolism was observed in fibroblasts following exposure to bEVs from ATCC 33277.ConclusionOur findings demonstrate that bEVs derived from P. gingivalis strains can induce changes in cellular processes in fibroblasts. This suggests a role of bEVs in the pathogenesis of periodontitis.
The alveolins are a family of intermediate filament-like proteins that form cytoskeletal structures in both free-living and parasitic members of the alveolate kingdom. Despite their important functions, the alveolins' biochemical properties and organizing principles are still poorly understood. Here, we characterize four alveolins of Plasmodium falciparum, the deadliest malaria parasite, to understand how alveolin domains mediate protein-protein interactions and highly specific recruitment to substructures of the cytoskeleton. Unexpectedly, we uncover variable dependence on alveolin domains for each substructure rather than an overarching mechanism. While PfIMC1e requires 1f to be sequentially recruited to the basal complex, PfIMC1c and PfIMC1g do not require interactions with each other to localize properly to the inner membrane complex. Moreover, alveolin domains are not interchangeable-they contain unique signatures for specialized localization. Finally, we identify a region outside the alveolin domain of PfIMC1e that is important for basal complex recruitment. These results provide direct evidence that alveolin domains mediate both alveolin-alveolin interactions and compartment-specific localization.
Glioblastoma, the most aggressive and fatal form of brain tumor, is characterized by rapid growth, extensive invasion of surrounding tissues, and significant angiogenesis. These and other types of cancer remain a leading cause of mortality worldwide, with conventional treatments such as chemotherapy, radiation, and surgery often limited by significant side effects. This has led to the pursuit of novel therapeutic approaches, including bacterial therapy, which utilizes bacteria's unique ability to target tumor microenvironments and deliver therapeutic agents. This research examines the antitumor effects of Streptomyces sp. M12 extract on the U87_MG glioblastoma cell line. The cytotoxicity of the extract was assessed using the MTT assay. Additionally, flow cytometry and scratch assays were conducted to evaluate cell migration. Furthermore, gene expression analysis for Bax, Bcl-2, Caspase-8, and Caspase-9 was performed to determine apoptotic effects. The MTT assay indicated strong anticancer activity with an IC50 value of 17.72 after 96 h of treatment. In vitro studies showed that the extract significantly promotes apoptosis, as evidenced by an 83.6% increase in apoptosis rates via flow cytometry. Moreover, the scratch assay demonstrated that the extract inhibited U87_MG cell migration, indicating antimetastatic potential. Real-time PCR analysis results revealed a 1.972-fold increase in Caspase-8 expression and a 0.468-fold decrease in Caspase-9 expression (p <= 0.001), suggesting that apoptosis is triggered through the extrinsic pathway. These findings emphasize the dual cytotoxic and antimigratory effects of the strain M12 extract, making it a promising candidate for glioblastoma treatment. Further investigation is necessary to clarify the molecular mechanisms involved and confirm its therapeutic potential in preclinical and clinical settings. This study highlights the significance of natural products, particularly those derived from Streptomyces sp. M12, an innovative cancer treatment strategy.
Klebsiella pneumoniae is a ubiquitous Gram-negative bacterium and a common cause of pneumonia, which leads to intense lung injury and mortality that are correlated with deregulated inflammation. Emerging evidence indicates that the NLRP3 inflammasome plays a critical part in regulating inflammatory processes in various infectious diseases. However, its role in K. pneumoniae infections remains elusive. In this study, we identified a siderophore, enterobactin (Ent), from K. pneumoniae as a key factor that induces NLRP3 activation in both the pulmonary epithelial cell line A549 and lung tissue from K. pneumoniae–infected mice. A549 epithelial cells infected with an Ent-deficient mutant (ΔentB) had lower Nlrp3, Asc, and Pro-caspase-1 gene expression, caspase-1 activity, and IL-18 secretion than cells infected with wild-type K. pneumoniae. No such effect was observed with THP-1 macrophages. Ent induced NLRP3 activation and IL-18 production in lung tissue of mice intranasally infected by K. pneumoniae strains. Interestingly, the recruitment of immune cells and production of inflammatory cytokines and chemokines were comparable in wild-type and ΔentB strain–infected mice. Taken together, our findings provide the first example of Ent playing a role in host inflammation control by targeting NLRP3.
Inflammatory bowel diseases are a group of chronic diseases with increasing global incidence and rising morbidity and mortality, contributing to a significant health burden. Mainstream treatments for IBD are focused on controlling inflammation and alleviating the symptoms, also aiming for intestinal barrier repair. Understanding the cellular and molecular mechanisms underlying intestinal inflammatory disorders is the key to developing more targeted therapies to treat IBD. The growth, differentiation, and proliferation of intestinal epithelial cells require energy. Since mitochondria provide the energy also required for intestinal epithelial cells to maintain homeostasis and barrier integrity, their dysfunction can lead to cell death and inflammation. While several studies have confirmed the link between gut microbial metabolites and mitochondrial function, conflicting results from studies in IBD models have presented challenges to a detailed understanding of this area. This review focuses on presenting data from existing literature and highlighting the therapeutic potential of gut microbiota–derived metabolites in restoring mitochondrial function, which may likely develop into therapeutic interventions in IBD. Trial Registration: ClinicalTrials.gov identifier: NCT01473524, NCT03724175
The epidermal growth factor receptor (EGFR), a protein located on the cell surface, belongs to the tyrosine kinase family and plays a crucial role in cell development and proliferation. Abnormal expression or mutations in the EGFR gene can lead to non–small cell lung cancer. Although established EGFR inhibitors have been effective in the treatment of cancer, they are associated with several side effects. As a result, there is an urgent need to develop novel EGFR inhibitors that can effectively target the receptor while causing no adverse side effects. In this study, a series of bis(6‐amino‐1,3‐dimethylpyrimidine‐2,4(1 H ,3 H )‐dione derivatives was synthesized in water at room temperature without the use of any catalyst, and pharmaceutical properties are investigated. Computational methods, including density functional theory (DFT), molecular docking, and molecular dynamics (MD), were utilized to investigate the chemical properties, drug‐like characteristics, and anticancer potential of the molecule. Quantum chemical calculations indicated that the molecules are relatively stable and exhibit significant electrophilic properties. The analysis of HOMO‐LUMO contour maps was conducted to illustrate charge density distributions that may be associated with biological activity. Docking studies with EGFR enzymes indicated that all compounds demonstrated favorable binding affinities, with docking scores ranging from −4.412 to −6.158 kcal/mol. Particularly, Compound 3f, with an energy of −6.158 kcal/mol, showed the best binding affinity, outperforming the native ligand, which had a docking score of −5.076 kcal/mol. The stability of the EGFR‐3f complex is significantly enhanced by the formation of five conventional hydrogen bonds and one carbon–hydrogen bond in ligand–protein interactions. MD simulations, which included analyses such as root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration (rGyr), molecular surface area (MolSA), and polar surface area (PSA), were conducted on the EGFR‐3f complex. It was found that the EGFR‐3f complex is stable, and the results show that Compound 3f has a strong interaction with the target enzyme.
To explore the peculiarities of neutrophil motility, two models of chemoattraction were created: a horizontal model, where a container with bacterial chemoattractant was attached laterally to the endotheliocyte monolayer, and a vertical model, simulating a pyemic focus in the lower part of the modified Boyden chamber. Low-molecular weight product secretion and/or degradation of Enterococcus faecalis caused “disorientations” of neutrophil migration with hyperproduction reactive oxygen species (ROS) by immune cells, while Proteus mirabilis inhibited both migration of most neutrophils and the production of ROS by them, while the activity of the remaining uninhibited neutrophils increased. Neutrophils generated ROS during migration, especially actively in the case of a large number of mobile cells (under stimulation with low-molecular weight product secretion and/or degradation of Enterococcus faecalis and Escherichia coli). Using high-resolution microscopy, it was shown that low-activity neutrophils cause changes in the morphology of endothelial cells during migration more than high-activity neutrophils. In the vertical migration model, the morphology of endothelial cells significantly changed during neutrophils diapedesis. It was observed that space between endothelial cells was increased (especially in the case of neutrophil swarming).
