Folia microbiologica最新文献

{"title":"Diversity and antimicrobial potential of endophytic fungi from Egyptian desert medicinal plants.","authors":"Tereza Ježková, Mo'men Hamed El-Katatny, Mohamed A Mawhoup, Usama Ramadan Abdelmohsen","doi":"10.1007/s12223-026-01560-9","DOIUrl":"https://doi.org/10.1007/s12223-026-01560-9","url":null,"abstract":"<p><p>Fungal endophytes from desert medicinal plants represent a promising yet underexplored source of bioactive secondary metabolites. In this study, 33 ascomycetous endophytes were isolated from five desert medicinal plant species collected in Egypt: Thymelaea hirsuta (L.) Endl., Zygophyllum album L.f., Zygophyllum coccineum L., Asparagus horridus L., and Asphodelus ramosus L. Molecular analyses revealed several species with potential thermotolerance or plant-growth-promoting capabilities, suggesting that they may contribute to host resilience in harsh arid environments. Ethyl acetate extracts of 29 isolates were screened for their antimicrobial activities against Escherichia coli, Klebsiella pneumoniae, methicillin-resistant Staphylococcus aureus, and Candida albicans. Several strains exhibited notable inhibitory effects. In particular, Canariomyces notabilis (GenBank accession nos. PZ502997, PZ530688) and Taifanglania parvispora (GenBank accession nos. PZ503016, PZ530694) displayed pronounced antimicrobial activity. Taifanglania parvispora CCF 6980 exhibited the strongest activity against MRSA (28 mm inhibition zone), whereas Canariomyces notabilis CCF 6973 showed broad-spectrum antimicrobial activity, producing inhibition zones of 20-31 mm, with the highest activity observed against Candida albicans. These findings highlight their potential for further investigation, especially as their secondary metabolites remain uncharacterised. Overall, this study expands the known diversity of fungal endophytes associated with Egyptian desert medicinal plants and highlights several taxa as potential sources of novel antimicrobial compounds.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148619034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Myco-synthesized silver nanoparticles from Aspergillus niger AH1 as multifunctional anti-Helicobacter pylori agents: Antibacterial, antibiofilm, anti-urease, and antibiotic-synergistic activities.","authors":"Mohammed S Abdulrahman, Amr H Hashem, Ebrahim Saied, Rafik Abdellatif Metwally, Fathy M Elkady","doi":"10.1007/s12223-026-01559-2","DOIUrl":"https://doi.org/10.1007/s12223-026-01559-2","url":null,"abstract":"<p><p>Helicobacter pylori remains a primary driver of chronic gastritis, peptic ulcers, and stomach cancer. However, surging antimicrobial resistance now causes treatment to fail in a significant number of patients. Because of their multi-target bactericidal processes, silver nanoparticles (AgNPs) have become a viable alternative antimicrobial therapy. In the current research, AgNPs were greenly synthesized employing Aspergillus niger AH1 (A. niger AH1) through an ecofriendly method. The biosynthesized AgNPs showed a characteristic surface plasmon resonance (SPR) peak at 420 nm, validating successful nanoparticles (NPs) development. Transmission electron microscope (TEM) analysis discovered primarily spherical and well-dispersed NPs with a size range of 8-38 nm, while dynamic light scattering (DLS) analysis exhibited an average hydrodynamic diameter of approximately 40 nm and a low polydispersity index (PDI = 0.122), indicating high colloidal stability. Furthermore, the X-ray diffraction (XRD) analysis illustrated the crystalline nature of the obtained AgNPs with characteristic face-centered cubic (FCC) diffraction peaks and 38.3 nm average crystallite size. The biosafety of the biosynthesized AgNPs was assessed toward normal cell lines; results revealed that the biosynthesized AgNPs are safe in use, where the IC50 was 306.4 and 336.9 µg/ml toward Wi-38 and Vero cell lines, respectively. The destructive ability of AgNPs against 17 clinical H. pylori isolates was thoroughly assessed using different microbiological assays. The minimum inhibitory concentration (MIC) values varied from 64 to 256 µg/mL, while minimum bactericidal concentration (MBC) values ranged from 64 to 1024 µg/mL. All isolates had MIC/MBC ratios of ≤ 4, indicating the bactericidal mode of action of AgNPs. In addition, AgNPs exhibited dose-dependent biofilm inhibition at sub-MIC concentrations, ranging from 1.31 to 60.42%. Mechanistic studies were subsequently performed using Hp13, the most susceptible isolate. In this representative isolate, AgNPs combined with amoxicillin and clarithromycin showed synergistic interactions in the checkerboard assay. AgNPs also suppressed urease activity in a concentration-dependent manner (IC₅₀ = 7.05 µg/mL), a concentration well below the isolate's MIC. Time-kill kinetics confirmed rapid bactericidal activity, while increased protein leakage indicated membrane disruption. These findings demonstrate that AgNPs possess potent antibacterial activity against clinical H. pylori isolates, whereas the mechanistic evidence was obtained using the representative isolate Hp13.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148619017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Taxonomic and functional inferences of cultivable endophytic fungi in two endemic Cerrado plants: dominance of Diaporthe across contrasting host phenologies.","authors":"Mayara Oliveira Sousa Rodrigues, Jefferson Brendon Almeida Dos Reis, Alexandra Martins, Danilo Batista Pinho, Lorena Carneiro Albernaz, Helson Mario Martins do Vale","doi":"10.1007/s12223-026-01533-y","DOIUrl":"https://doi.org/10.1007/s12223-026-01533-y","url":null,"abstract":"<p><p>Host phenology is an important determinant of the microbial community, yet how it shapes the evolution and function of endophytic fungi in native plants of the Cerrado remains poorly understood. We investigated cultivable foliar fungal communities in Connarus suberosus (evergreen) and Diospyros lasiocalyx (deciduous) using an integrative approach. A total of 365 isolates were obtained, and most belonged to the genus Diaporthe. Both host plants harbored communities with similar alpha and beta diversity patterns, characterized by high taxonomic dominance and consistent composition. Beta diversity analyses revealed no significant differences in community composition between host species (PERMANOVA, p > 0.05). The high abundance of Diaporthe in both hosts likely contributed to the observed compositional similarity. Phylogenetic community structure was consistent between hosts, characterized by stochastic assembly for most taxa. The only distinct signal was a significant phylogenetic clustering for the genus Diaporthe in the deciduous D. lasiocalyx (NTI = 0.75; p = 0.042), whereas Diaporthe in C. suberosus followed a stochastic pattern (NTI = -0.60; p = 0.677). For non-dominant genera, assembly rules remained stochastic in both host species (p > 0.05). The bipartite network analysis indicated compartmentalization, with 72.4% of genera classified as specialists. Diaporthe showed significant negative correlations with Penicillium and Colletotrichum (p < 0.001), indicating non-random association patterns among dominant taxa. Functionally, Mantel analyses indicated that variation in plant-pathogen and litter-saprotroph guilds was associated with taxonomic community structure. Overall, our results indicate that contrasting host phenologies had limited effects on the diversity and composition of cultivable foliar endophytic fungal communities. Instead, both hosts were characterized by similar community structures dominated by Diaporthe, with only a subtle phylogenetic signal detected for this genus in the deciduous host.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148619027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From mycelium to medicine: fungal strategies in the fight against resistance, cancer, and viral infections-insights from egyptian studies.","authors":"Ramy M Shady, Eman El-Gebaly, Mahmoud A Yassein, Mona H El-Gayar","doi":"10.1007/s12223-026-01547-6","DOIUrl":"https://doi.org/10.1007/s12223-026-01547-6","url":null,"abstract":"<p><p>The increasing prevalence of antimicrobial resistance (AMR), alongside the global burden of cancer and viral infections, poses a major threat to human health and challenges existing therapeutic options. Multidrug-resistant pathogens, treatment failures in cancer, and emerging viral strains demand the urgent development of safer and more effective alternatives. Natural products, particularly fungal metabolites, have long been recognized as valuable sources of bioactive compounds with diverse pharmacological activities. Mushrooms, in particular, are rich in polysaccharides, terpenoids, flavonoids, phenolics, and other metabolites that exhibit antimicrobial, antiviral, antioxidant, immunomodulatory, and cytotoxic properties. Historical and modern evidence highlights their therapeutic potential against infections and malignancies, offering both preventive and curative benefits. In Egypt, where liver, breast, and colorectal cancers are highly prevalent, and AMR rates continue to rise, the search for novel natural agents is especially critical. Medicinal mushrooms such as Ganoderma lucidum, Lentinula edodes, Pleurotus spp., and Hericium erinaceus have demonstrated promising activities in vitro and in vivo, supporting their role as complementary or alternative therapies. Advances in extraction methods, from conventional hot water and solvent techniques to enzyme-assisted and supercritical fluid extraction, have further enhanced the recovery of potent fungal metabolites. This review summarizes the global and regional burden of AMR, cancer, and viral infections with particular emphasis on the Egyptian context, explores the bioactive potential of mushrooms, highlights key groups of fungal metabolites with therapeutic applications, and presents recent findings from Egyptian studies on locally sourced medicinal mushrooms. Harnessing these natural compounds offers a sustainable strategy for developing next-generation agents to overcome resistance, improve treatment outcomes, and support global health.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148590879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into the genomic features of the emerging pathogens Cronobacter malonaticus and Cronobacter turicensis.","authors":"Felipe Pinheiro Vilela, Laura Toniolo Dias, Juliana Pfrimer Falcão","doi":"10.1007/s12223-026-01561-8","DOIUrl":"https://doi.org/10.1007/s12223-026-01561-8","url":null,"abstract":"<p><p>Cronobacter spp. are emerging opportunistic bacteria that are able to survive to diverse stresses. They infect mainly children through contaminated food. Despite the growing concern surrounding them, Cronobacter malonaticus (C. malonaticus) and Cronobacter turicensis (C. turicensis) remain understudied. This study aimed to characterize the genomic traits of C. malonaticus and C. turicensis isolated worldwide. A total of 104 C. malonaticus and 89 C. turicensis genomes from eight countries and diverse sources were screened for antimicrobial resistance and virulence genes, plasmids, and prophages. Genotyping was performed by Multi-Locus Sequence Typing (MLST), core-genome MLST, and Single-Nucleotide Polymorphism (SNP) clusters. Only six C. malonaticus genomes harbored resistance genes, while all C. turicensis genomes harbored the fosfomycin resistance gene fos. The IncFIB(pCTU1) and IncFIB(pCTU3) plasmid replicons and the prophage 118970_sal3 were the most frequent. Seventy-one virulence genes related to chemotaxis, flagella, hemolysins, intra-macrophage survival, outer membrane proteins, stress response and transcriptional regulation were found in all genomes. All molecular typing methods suggested a high intra-species genomic diversity, regardless of the isolation source or country. In conclusion, the high frequency of virulence genes in C. malonaticus and C. turicensis suggests their pathogenic potential and capacity to cause infection in humans, reinforcing the need to not underestimate the potential hazard of understudied Cronobacter species. The high genetic diversity, the presence of certain antimicrobial resistance genes, and the variety of plasmids and prophages reinforce the importance of monitoring C. malonaticus and C. turicensis worldwide by public health and food safety authorities.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148577330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of cultivation mode for pilot-scale biomass and B-phycoerythrin production by red microalgae Porphyridium purpureum in different seasons.","authors":"Andrei B Borovkov, Alexander S Lelekov, Irina N Gudvilovich, Anna L Avsiyan, Olga A Rylkova, Yana D Zhondareva, Viktoria S Klochkova, Tatyana M Novikova","doi":"10.1007/s12223-026-01558-3","DOIUrl":"https://doi.org/10.1007/s12223-026-01558-3","url":null,"abstract":"<p><p>Development of sustainable technologies for production of the red microalga Porphyridium purpureum is an important objective to reduce the production costs and expand its incorporation into food, feed, and nutraceutical products. The aim of this study was to evaluate the production potential of P. purpureum under different cultivation modes and to optimize its pilot-scale cultivation in open ponds under mid-latitude climate conditions (spring-summer and autumn). Batch and semicontinuous photoautotrophic cultivation, as well as batch mixotrophic cultivation (with glycerol), were compared in terms of biomass and B-phycoerythrin (B-PE) productivity. The highest biomass productivity (22.3 g m^-2 day^-1) was obtained under mixotrophic cultivation in summer, which was 2-3 times higher than in photoautotrophic modes. However, mixotrophic growth markedly reduced the B-PE content in the biomass (down to 2.85% vs. 6-7% under photoautotrophic conditions). In photoautotrophic batch and semicontinuous cultures, the areal biomass productivity reached 10.5 and 13.8 g m^-2 day^-1, respectively, with B-PE productivity up to 0.71 g m^-2 day^-1. A strong correlation was found between productivity and the daily solar energy input; the optimal daily irradiance was ≥ 5 MJ m^-2 day^-1. The associated bacterial biomass remained below 0.014% of the total biomass and did not significantly affect culture performance.We conclude that photoautotrophic batch and semicontinuous cultivation are preferable for producing B-PE-rich biomass, whereas mixotrophic cultivation is advantageous for rapid biomass accumulation but not for pigment synthesis. Greenhouse pond systems provide a feasible and scalable platform for industrial cultivation of P. purpureum.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148561283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antioxidant and antibacterial potency of Pleurotus citrinopileatus: by GC-MS characterization, bioactive compound profiling, synergy analysis, and In-Silico validation of microbial target interactions.","authors":"Anupriya Chaudhary, Saba Ehsan, Supriya Maurya, Shivanand Yadav, Mohan P Singh","doi":"10.1007/s12223-026-01555-6","DOIUrl":"https://doi.org/10.1007/s12223-026-01555-6","url":null,"abstract":"<p><p>The rapid development of antimicrobial resistance has intensified the demand for safe, multifunctional, and mechanistically validated natural antimicrobials beyond conventional antibiotics. Edible mushrooms, particularly Pleurotus species, represent an underexplored reservoir of bioactive metabolites; however, most studies remain limited to preliminary bioactivity screening without mechanistic confirmation. In this study, the antibacterial and antioxidant potential of Pleurotus citrinopileatus was systematically assessed through integrated experimental and in-silico methods. Aqueous (AEPC), ethanolic (EEPC), and methanolic (MEPC) extracts were subjected to GC-MS profiling, antioxidant assays, antibacterial activity, synergistic interaction study of Mushroom with plants, molecular docking, and 100-ns molecular dynamics (MD) simulations. GC-MS analysis identified 9, 19, and 25 bioactive compounds in AEPC, EEPC, and MEPC, respectively, with sterols such as ergosterol and cholesta-8,24-dien-3-ol predominating in MEPC. Methanolic extract exhibited the strongest antioxidant activity (91.18% DPPH scavenging; IC₅₀ ≈ 8 µL/mL), while EEPC demonstrated superior antibacterial efficacy, producing pronounced inhibition zones against Proteus vulgaris, Pseudomonas aeruginosa, and Staphylococcus aureus. All extracts showed bactericidal activity with MIC values ranging from 25-150 mg/mL and MBC/MIC ratios ≤ 2. Synergistic combinations with neem and tulsi enhanced antibacterial zones by 5-7 mm and increased antioxidant activity up to 92.28%. Molecular docking revealed strong binding affinities (- 7.2 to - 11.9 kcal/mol) of key sterols against multiple bacterial targets, comparable to ciprofloxacin, with ergosterol exhibiting the highest affinity toward P. aeruginosa alginate lyase. MD simulations confirmed the stability of protein-ligand complexes, supported by low RMSD, stable radius of gyration, and persistent hydrogen-bond interactions. Overall, P. citrinopileatus emerges as a promising natural reservoir of antibacterial and antioxidant agents, offering a synergistically enhanced, mechanistically validated strategy for combating pathogenic bacteria. These findings support the potential of Pleurotus citrinopileatus as a natural source of antioxidant and antibacterial agents, warranting further toxicological and in vivo investigations for therapeutic applications.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148535615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection and molecular characterization of hepatitis E virus in food-producing animals in Slovakia.","authors":"Alica Pavlova, Bozena Kocikova, Michaela Urda Dolinska, Anatolij Kovalenko, Rene Mandelik, Jaroslav Novotny, Anna Jackova","doi":"10.1007/s12223-026-01554-7","DOIUrl":"https://doi.org/10.1007/s12223-026-01554-7","url":null,"abstract":"<p><p>Hepatitis E virus (HEV) is an emerging public health concern in developed countries, with most infections linked to the foodborne transmission of the zoonotic genotype HEV-3. With increasing number of viral hepatitis E cases in human population in Slovakia, knowledge of the situation in the food-producing animal population is becoming increasingly important. Detection of HEV RNA was performed in 290 samples (collected during period of March 2023 to August 2025) from four different species of food-producing animals - pigs, cows, sheep and goats. The presence of HEV RNA was confirmed by real-time RT-PCR in 5 out of 120 (4.2%) fecal samples from pigs in fattening stage originated from a same farm. Prevalence of HEV RNA was relatively lower than in previous findings, what may reflect limitation in sampling strategy. Phylogenetic analyses of selected ORF1 and ORF2 sequences showed that they clustered within genotype HEV-3f (HEV-3 group 1). Presence of this genotype in Slovak pigs supports possibility of zoonotic transmission, since it is most commonly described in the Slovak human patients with severe course of infection. Despite the fact that HEV is circulating in pigs from Slovakia (n = 5/120), we did not detect HEV RNA in cows, sheep or goats (n = 0/170). The absence of HEV RNA in food-producing ruminants has been confirmed during our study period in Slovakia, which point to the fact that these species are probably not the main HEV reservoir compared to pigs. Ongoing research will be essential for tracking HEV circulation across reservoirs.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148520042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome-wide analysis of the Escherichia coli Keio collection reveals genetic determinants associated with ferulic acid responses.","authors":"Merve Sezer Kürkçü, Hatice Öztürkel Kabakaş, Kadriye Aslıhan Onat Taşdelen, Esra Dibek, Bekir Çöl","doi":"10.1007/s12223-026-01556-5","DOIUrl":"https://doi.org/10.1007/s12223-026-01556-5","url":null,"abstract":"<p><p>Ferulic acid (FA) is a widespread plant derived phenolic compound with diverse biological activities, including antimicrobial, antioxidant, and anti-inflammatory properties. In addition to its importance in food, cosmetic, and pharmaceutical applications, FA is abundant in lignocellulosic biomass, where it functions both as a microbial stress factor and as a metabolizable aromatic intermediate during bioconversion processes. Despite its broad biological and biotechnological relevance, the genetic basis underlying bacterial adaptation and tolerance to FA remains poorly understood. In this study, we performed a genome-wide screen using the Escherichia coli Keio knockout collection to identify genes associated with FA sensitivity and tolerance. The analysis revealed that bacterial responses to FA involve multiple interconnected cellular systems rather than a single resistance mechanism. Mutants defective in outer membrane lipid homeostasis (Mla system) and aromatic acid efflux functions (aaeA/aaeR, acrB) displayed pronounced sensitivity to FA, highlighting the importance of membrane integrity and transport systems during phenolic stress. Genes involved in Fe-S cluster biogenesis (sufS, sufA), hydrogenase maturation (hypD, hybF), molybdenum transport and cofactor metabolism (modB, modC, modE) and electron transport associated functions (ccmE) were also associated with altered FA responses. In addition, disruption of global regulatory genes (seqA, dksA, and rlmE) impaired tolerance, whereas deletion of mutL increased resistance. Functional enrichment and network analyses further linked FA responses to pathways associated with membrane homeostasis, redox-associated processes, transport systems, and metabolic adaptation. Overall, this study provides a genome wide genetic framework for understanding bacterial responses to FA and identifies candidate genes and cellular systems potentially involved in phenolic stress adaptation. These findings expand current knowledge of microbial adaptation to plant derived phenolic compounds and provide a basis for future studies investigating microbial stress physiology, phenolic tolerance mechanisms, and strategies to modulate bacterial sensitivity under phenolic stress conditions.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148497405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Precision repurposing of clinically characterized molecules targeting dengue virus RNA-dependent RNA polymerase: an in silico identification and in vitro validation.","authors":"Hrithika Panday, Babita Bohra, Rahul Shukla, Vivek Dhar Dwivedi, Abhimanyu Kumar Jha","doi":"10.1007/s12223-026-01552-9","DOIUrl":"https://doi.org/10.1007/s12223-026-01552-9","url":null,"abstract":"<p><p>The dengue virus has developed an effective replication mechanism that enables rapid viral replication in human hosts. The use of a molecular bottleneck offers an ideal approach for antiviral intervention, especially when no clinically authorized antivirals are available against dengue. The replication process is challenging due to functional redundancy. One of the core antiviral targets is the viral RNA-dependent RNA polymerase (RdRp), a conserved and essential component of the DENV replication machinery with no mammalian homolog, which represents a promising target for antiviral intervention. This study employed a multi-tiered drug repurposing approach integrating computational screening, high-throughput virtual screening (HTVS), standard precision (SP), and extra precision (XP) molecular docking of SelleckChem FDA-approved & Passed Phase I Drug Library compounds against the DENV RdRp (PDB:5K5M), followed by 200 ns molecular dynamics (MD) simulations, free binding energy analysis, free energy landscape (FEL) analysis, and in vitro antiviral validation. From the screening cascade, Proanthocyanidin and Stachyose were identified as lead candidates with Glide XP docking scores of -11.34 and - 13.08 kcal/mol and Molecular Mechanics/Generated Born Surface Area (MM-GBSA) binding free energies of -52.35 ± 5.29 kcal/mol, respectively. These lead candidates established stable interactions with important catalytic and regulatory residues, including Arg⁷²⁹, Thr⁷⁹⁴, Ser⁷⁹⁶, Asp⁶⁶⁴, and Tyr^766, indicating their ability to disrupt key polymerase activity. The stability of the candidates was further confirmed by Molecular dynamics simulations based on the minimal variations of RMSD and compactness of the protein compared with the lead structures, which collectively indicated their compatibility with the polymerase allosteric site. Critically, in vitro assays conducted on DENV infected cells confirmed the Proanthocyanidin exhibited potent dose-dependent antiviral activity with IC₅₀ values of 4.26-7.07 µM across DENV serotypes 1-4, with CC₅₀ >100 µM and selectivity indices > 14, indicating a favorable therapeutic window. These findings identify Proanthocyanidin as a promising RdRp-targeting antiviral candidate and demonstrate the value of integrating computational and experimental approaches for dengue drug discovery.</p>","PeriodicalId":12346,"journal":{"name":"Folia microbiologica","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148469810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}