MicrobiologyOpen最新文献

{"title":"The Mycorrhizal Fungal Species Funneliformis mosseae Reshapes Rhizosphere Microbial Metabolic Pathways of Soybeans Under Tetracycline Stress","authors":"Chao Yang,&nbsp;Baiyan Cai,&nbsp;Harry Lye Hin Chong,&nbsp;Juan Li,&nbsp;Linghui Li,&nbsp;Jean Wan Hong Yong,&nbsp;Khim Phin Chong","doi":"10.1002/mbo3.70385","DOIUrl":"https://doi.org/10.1002/mbo3.70385","url":null,"abstract":"<p>Studies have demonstrated that arbuscular mycorrhizal fungi (AMF) can alter the rhizosphere microbial communities during exposure to tetracycline, thereby alleviating the adverse effects of antibiotics. We hypothesized that <i>Funneliformis mosseae</i> (<i>F. mosseae</i>) reshapes soil metabolite composition and associated-microbial pathways under tetracycline stress and that these metabolite changes are associated with the rhizosphere microbial communities. To test this hypothesis, microbiological profiling with metabolomics approaches were carried out to investigate how AMF reshape rhizosphere metabolite profiles in soybeans undergoing tetracycline stress. Specifically, inoculation with <i>F. mosseae</i> altered the soil metabolite profiles, with 34 differential metabolites identified, including 14 upregulated and 20 downregulated compounds, mainly amino acids, sugar phosphates, fatty acids, polyphenols, triterpenes, and heterocyclic compounds. In addition, 19 differential metabolic pathways were identified and classified into four metabolic clusters: polyunsaturated fatty acids and oxidative stress-related metabolism, carbon source and energy metabolism, amino acid and sulfur-containing metabolism, and secondary metabolism and defense responses. The correlation analysis between soil metabolites and published rhizosphere microbial data revealed 14 metabolites, including Trehalose-6-phosphate, increased with bacterial abundance, while five metabolites decreased; similarly, four metabolites increased and three decreased with fungal abundance. Correlation network analysis further indicated that 16 differential metabolites were significantly associated with 8 differential bacterial genera, and 12 differential metabolites were significantly associated with six fungal genera. Overall, our findings demonstrated that <i>F. mosseae</i> plays a crucial role in regulating microbial metabolism and interactions in tetracycline-contaminated soils, providing valuable insights into the mechanisms by which AMF alleviate tetracycline-induced stress in soils.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 5","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70385","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148860045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unlocking the Bioactive Potential of Streptomyces: A Multidisciplinary Approach to Strain Improvement","authors":"Anum Goraya,&nbsp;Anila Fariq,&nbsp;Aneela Fatima,&nbsp;Syed Hussain Imam Abidi,&nbsp;Sohail Ameer Marwat,&nbsp;Gholamreza Abdi","doi":"10.1002/mbo3.70379","DOIUrl":"10.1002/mbo3.70379","url":null,"abstract":"<p><i>Streptomyces</i> is a genus of Gram-positive bacteria renowned for its remarkable ability to produce a diverse array of secondary metabolites (SMs), many of which possess significant pharmaceutical and agricultural value. Unlocking the full biopotential of <i>Streptomyces</i> is increasingly important in the quest for new therapeutics and sustainable solutions to global challenges, such as antibiotic resistance and food security. This review paper aims to bridge gaps in the literature by providing a comprehensive, integrative overview of recent advances in <i>Streptomyces</i> strain improvement. It discusses optimization of SM production in <i>Streptomyces</i> through a multidisciplinary approach. It also highlights the integration of traditional methods with modern genetic and metabolic engineering techniques to improve biosynthetic pathways, as well as adaptive laboratory evolution for strain development, systems, and fermentation, aiming to maximize the production of valuable bioactive compounds. While previous studies have explored individual aspects of strain optimization, this review presents a unified perspective on how these strategies can be applied effectively. This review not only enhances the understanding of <i>Streptomyces</i> biopotential but also addresses the need for a holistic framework that considers both established and emerging techniques in strain improvement. By filling these gaps, this review contributes to a more complete understanding of how to optimize <i>Streptomyces</i> for the production of valuable bioactive compounds, guiding future innovations and applications in biotechnology and pharmaceuticals.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 4","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13501113/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148808972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Involvement of the Cryptococcal Yeast Kexin Protease in the Proteolytic Activation of the Uncleaved Influenza Virus Hemagglutinin Glycoprotein","authors":"Nolwazi F. Ntshangase,&nbsp;Khwezi Mdana,&nbsp;Nozethu Mjokane,&nbsp;Winschau F. van Zyl,&nbsp;Jacobus Albertyn,&nbsp;Olihile M. Sebolai","doi":"10.1002/mbo3.70384","DOIUrl":"10.1002/mbo3.70384","url":null,"abstract":"<p>Infectious diseases typically involve a single pathogen harming its host. However, in clinical settings, co-infections also occur. This study investigated the potential interaction between <i>Cryptococcus</i> (<i>C</i>.) <i>neoformans</i> and influenza virus by assessing whether the cryptococcal yeast kexin protease (Kex2p) could activate the uncleaved hemagglutinin glycoprotein. Protein-protein docking was performed using HADDOCK and independently validated using AlphaFold3. 6x His-tagged truncated <i>KEX2</i> gene was expressed in <i>E. coli</i> BL 21 (DE3), and the recombinant protein was purified using nickel ion affinity chromatography. Successful protein production was confirmed by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, anti-His immunoblotting, and mass spectrometry. Recombinant Kex2p was evaluated in a biochemical peptide cleavage assay using a fluorogenic 12-mer peptide mimicking the hemagglutinin HA1/HA2 site as substrate, with furin serving as the reference protease. HADDOCK predicted favorable binding of Kex2p to hemagglutinin (HADDOCK score = −119.2 ± 8.7; RMSD = 1.1 ± 0.2 Å), comparable to the furin-hemagglutinin complex (HADDOCK score = −115.9 ± 5.7; RMSD = 2.1 ± 1.3 Å). AlphaFold 3 independently reproduced the HADDOCK-predicted binding orientations, yielding moderate-confidence complexes for hemagglutinin-furin (ipTM = 0.50, pTM = 0.56; RMSD = 3.634 Å) and hemagglutinin-Kex2p (ipTM = 0.41, pTM = 0.58; RMSD = 3.243 Å). In enzymatic assays, recombinant Kex2p exhibited a significantly higher Vmax than furin (<i>p</i> = 0.0411), indicating greater catalytic activity toward the hemagglutinin cleavage peptide. These findings provide the first biochemical and complementary computational evidence that <i>C. neoformans</i> Kex2p may recognize influenza hemagglutinin, supporting its potential role in hemagglutinin activation during cryptococcal-influenza co-infection.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 4","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13504229/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148812810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genomic Epidemiology of Multidrug-Resistant Clinical Klebsiella pneumoniae From Pakistan","authors":"Hakeem Zada,&nbsp;Muhammad Qasim,&nbsp;Mubashir Hussain,&nbsp;Abdul Rehman,&nbsp;Hassan Naveed,&nbsp;Noor Bahadar,&nbsp;Najibullah Anwari","doi":"10.1002/mbo3.70381","DOIUrl":"10.1002/mbo3.70381","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Antimicrobial-resistant <i>Klebsiella pneumoniae</i> is a major clinical threat in Pakistan and the wider South Asian region, where genomic surveillance remains limited. We analyzed 122 publicly available human clinical <i>K. pneumoniae</i> whole-genome sequencing datasets from Pakistan to define lineage structure, antimicrobial-resistance determinants, virulence-associated loci, surface-antigen profiles, plasmid replicons, and genomic relatedness.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Reads were extracted, quality-filtered and assembled de novo, and assembly quality was assessed. Assemblies were characterized using Kleborate and ABRicate with the PlasmidFinder database. Trimmed reads were mapped to the <i>K. pneumoniae</i> MGH 78578 reference genome, and high-confidence biallelic SNPs (QUAL ≥ 30; per-isolate depth ≥ 10) were used to calculate pairwise genomic distances.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The cohort contained 23 sequence types and was dominated by ST15 (41/122, 33.61%), followed by ST48 (17/122, 13.93%), ST336 (11/122, 9.02%), ST711 (7/122, 5.74%), and ST3805 (7/122, 5.74%). Acquired resistance profiling detected 48 distinct antimicrobial-resistance genes. <i>bla</i>_CTX-M-15 was present in 121 isolates (99.18%), <i>bla</i>_VEB-5 in 45 (36.89%), and <i>bla</i>_NDM-1 in 16 (13.11%). <i>bla</i>_NDM-1-positive isolates occurred in four principal ST/capsule/O-locus backgrounds. Yersiniabactin and aerobactin loci were detected in 48 (39.34%) and 43 (35.25%) isolates, respectively; 43 isolates had a Kleborate virulence score ≥ 3, whereas colibactin and <i>rmpADC</i> were not detected. IncFIB(K)_1_Kpn3 was the most frequent plasmid replicon marker (101/122, 82.79%). Analysis of 169,220 high-confidence biallelic SNP sites yielded 7381 pairwise comparisons, with a median distance of 30,224 SNPs and no pairs differing by ≤ 10 SNPs.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The cohort showed broad genomic diversity, near-universal <i>bla</i>_CTX-M-15 carriage, lineage-structured <i>bla</i>_NDM-1 backgrounds, frequent siderophore-associated virulence loci, and distinct plasmid-replicon profiles. The findings support multiple co-circulating multidrug-resistant genomic backgrounds rather than a single clonal expansion and provide a reference point for genomic surveillance in Pakistan.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 4","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13500998/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148808994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Green-Synthesized Silver Nanoparticles Against Acinetobacter baumannii: A Systematic Review of Antibacterial Activity, Mechanisms of Action, Toxicity, and Antibiofilm Effects","authors":"Shahla Shahbazi,&nbsp;Kimia Rafieibuzhani,&nbsp;Keyghobad Ghadiri,&nbsp;Yadollah Bahrami,&nbsp;Roya Chegene Lorestani,&nbsp;Maryam Meskini,&nbsp;Samira Sabzi,&nbsp;Mosayeb Rostamian","doi":"10.1002/mbo3.70378","DOIUrl":"10.1002/mbo3.70378","url":null,"abstract":"<p><i>Acinetobacter baumannii</i> is a major multidrug-resistant nosocomial pathogen, and new antimicrobial strategies are urgently needed. Green-synthesized silver nanoparticles (AgNPs) have emerged as promising candidates because of their broad antibacterial activity and potentially improved biocompatibility. This systematic review evaluated the antibacterial effects of pure, plant-mediated AgNPs against <i>A. baumannii</i> isolates. PubMed, Scopus, and Web of Science were searched from database inception to October 5, 2025 according to PRISMA guidelines. Eligible studies were original English-language reports assessing pure green-synthesized AgNPs against <i>A. baumannii</i>. Sixty-three studies met the inclusion criteria. Green AgNPs were generally active against <i>A. baumannii</i> and more often showed stronger effects than the corresponding plant extracts. The most commonly proposed mechanisms were reactive oxygen species generation, membrane and cell–wall disruption, increased permeability, and damage to proteins, lipids, or DNA. Biofilm data were limited but suggested promising inhibitory potential. Toxicity findings were mixed, ranging from good biocompatibility to cytotoxicity in sensitive cell models. Plant-mediated AgNPs show credible antibacterial potential against <i>A. baumannii</i>, but standardized synthesis, rigorous characterization, biofilm-focused testing, and in vivo safety studies are still needed before clinical translation.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 4","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13487469/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148795264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Standardized 16S Meta-Analysis Reveals Consistent Host-Associated Patterns in Laminariales Epiphytic Microbiomes","authors":"J. Z. Florez,&nbsp;A. Zárate,&nbsp;P. Bruna,&nbsp;B. Leyton-Carcaman,&nbsp;V. Molina,&nbsp;M. B. Hengst,&nbsp;C. Camus,&nbsp;M. Abanto,&nbsp;L. Barrientos,&nbsp;A. H. Buschmann","doi":"10.1002/mbo3.70372","DOIUrl":"https://doi.org/10.1002/mbo3.70372","url":null,"abstract":"<p>Macroalgae and their associated microbes form tightly integrated holobionts, yet cross-study comparisons of epiphytic microbiomes remain constrained by heterogeneous sampling designs, primer selection, and analytical pipelines. We performed a harmonized meta-analysis of publicly available 16S rRNA gene datasets to examine diversity, community structure, and inferred functional profiles within a common analytical framework. A structured search identified 16 studies, totaling 763 samples, from macroalgae and adjacent seawater across four oceanic regions. All datasets were reprocessed using a standardized workflow to ensure cross-study comparability. The compiled dataset was strongly skewed towards brown macroalgae (Phaeophyceae) and the V4 region of the 16S gene, highlighting both the prominence of Laminariales in current research and the need for methodological harmonization. Within this framework, alpha diversity differed among macroalgal orders, with Fucales hosting the richest epiphytic assemblages, Desmarestiales intermediate diversity, and Laminariales the lowest, while seawater exhibited intermediate values. Community composition was structured by host taxonomic identity and sample type. Within Laminariales, thalli supported assemblages distinct from seawater, sharing a limited taxonomic core and displaying reproducible genus-level signatures. Trait-based functional annotation indicated enrichment of aerobic chemoheterotrophy and polysaccharide-associated metabolisms in Laminariales communities, whereas seawater showed greater representation of nitrogen- and sulfur-related processes. These findings demonstrate that cross-study reprocessing resolves consistent host-associated patterns and establishes a quantitative framework for future multi-omics and experimental investigations.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 4","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70372","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148783597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of ClpX and MsrA/B in the Oxidative and Cell Wall Stress Response in Bacillus anthracis Sterne","authors":"Aeron B. Pennington,&nbsp;Salina Hona,&nbsp;Josey I. Austin,&nbsp;Kelsey C. Waite,&nbsp;Mikaela D. Stewart,&nbsp;Shauna M. McGillivray","doi":"10.1002/mbo3.70377","DOIUrl":"10.1002/mbo3.70377","url":null,"abstract":"<p>ClpX functions as a component of the ClpXP protease, a conserved intracellular protease that regulates protein turnover, stress responses, and virulence in multiple bacterial species. Our lab has established that <i>clpX</i> is necessary for resistance to cell envelope targeting antibiotics, such as penicillin and daptomycin in <i>Bacillus anthracis</i> Sterne. Previous microarray data identified the <i>msrA/B</i> gene encoding a bifunctional methionine sulfoxide reductase as upregulated in the Δ<i>clpX</i> mutant. Methionine sulfoxide reductases (Msr) repair oxidatively damaged proteins by reducing methionine sulfoxide residues back to methionine. While Msr enzymes are primarily associated with oxidative stress, cell wall antibiotics induce expression of <i>msrA1</i> and <i>msrB</i> in <i>S. aureus</i>. Here, we investigated the role of MsrA/B in oxidative and cell envelope stress. Our results show that although hydrogen peroxide and paraquat induce <i>msrA/B</i> expression, the Δ<i>msrA/B</i> strain was not susceptible to either oxidant, whereas the Δ<i>clpX</i> strain was sensitive to both. We also found that loss of <i>msrA/B</i> conferred penicillin-specific sensitivity, but, unlike Δ<i>clpX</i>, increased sensitivity was not seen with other cell wall or cell membrane targeting antibiotics. Inactivation of the catalytic cysteine of either Msr domain of MsrA/B failed to complement, suggesting that the reducing activity of MsrA/B is required for penicillin resistance. These findings indicate that while MsrA/B contributes to penicillin resistance, other proteins in the ClpXP modulon must also play a role in oxidative and cell envelope stress.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 4","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13478556/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148761881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental, Genomic, and Structural Evidence Supporting Putative PET-Hydrolases in Thermophilic Bacteria Isolated From Hot Springs in Cajamarca, Peru","authors":"Marco A. Rivera-Jacinto,&nbsp;Claudia Rodríguez-Ulloa,&nbsp;Sara R. Briones-Ramírez,&nbsp;Betsy Quispe-Cruz,&nbsp;Sandra Carrasco-Tarrillo,&nbsp;Diego A. Leonardo,&nbsp;Juan P. Cardenas","doi":"10.1002/mbo3.70376","DOIUrl":"https://doi.org/10.1002/mbo3.70376","url":null,"abstract":"<p>Polyethylene terephthalate (PET) waste represents a major environmental challenge due to limited recycling solutions. Thermophilic bacteria from geothermal environments harbor diverse enzymatic machinery adapted to extreme conditions, offering promising biocatalysts for plastic degradation; however, biological resources from Peru and other South American countries remain scarce. We characterized four bacterial strains isolated from two geothermal sites in Cajamarca, Peru, screened for PET hydrolysis at 50°C. Whole-genome sequencing using hybrid assembly achieved near-complete circular genomes. GTDB-Tk classification identified three species: <i>Neobacillus thermocopriae</i> (strain 19A), <i>Bacillus licheniformis</i> (strains 16P and BI2), and <i>Brevibacillus agri</i> (strain BI8). Quantitative assays revealed that strain 16P achieved the highest mass loss (0.598%), followed by strain BI8 (0.449%). ATR-FTIR analysis of the incubated sheets showed a significant reduction of the ester carbonyl index in strains 16P, 19A, and BI8 relative to both non-incubated PET and an abiotic control, whereas strain BI2 did not differ from the controls, indicating preferential modification of ester bonds at the sheet surface. Genome mining and structure-based homology searches identified multiple candidate enzymes similar to validated PETases and carboxylesterases, including PETase46-like homologs in strains BI8 and 16P and a terephthalate-active carboxylesterase homolog in strain 16P. Molecular docking supported the conservation of catalytic geometry and substrate-binding sites in these candidates. This work represents one of the first systematic genomic and structural characterizations of putative PET-hydrolases in Peruvian geothermal bacteria, expanding knowledge of extremophile diversity and advancing thermostable enzymes for sustainable plastic waste management.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 4","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70376","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beyond the Standard Antibiogram: Unveiling the Roles of pH and Salinity in Modulating Gentamicin Efficacy Against Escherichia coli in Urinary Tract Infections","authors":"Abdelwahab Rai,&nbsp;Mahdia El-djohra El-amina Saoud,&nbsp;Nesrine Tabchouche,&nbsp;Hamdi Bendif,&nbsp;Stefania Garzoli,&nbsp;Lotfi Mouni","doi":"10.1002/mbo3.70375","DOIUrl":"10.1002/mbo3.70375","url":null,"abstract":"<p>Urinary tract infections are highly prevalent diseases with a broad spectrum of clinical manifestations. This study investigates the influence of two key abiotic factors, pH and salinity, on the growth and antibiotic susceptibility of <i>Escherichia coli</i> ATCC 25922, <i>Pseudomonas aeruginosa</i> ATCC 27853, and a clinical <i>E. coli</i> isolate obtained from a human urine sample. Growth kinetics and gentamicin susceptibility were evaluated across a pH range (4.5–11.0) and NaCl concentrations (0–1000 mM) using Luria–Bertani and Mueller–Hinton (MH) media. In parallel, real urine was analyzed, and urine-mimicking MH media were prepared by adjusting pH and salinity independently and in combination. Gentamicin susceptibility was strongly influenced by environmental conditions. Salinity pre-exposure increased <i>E</i>. <i>coli</i> and <i>P</i>. <i>aeruginosa</i> resistance from 23.0 to 19.0 mm and from 25.5 to 18.5 mm at 800 mM, respectively. Direct pH modification enhanced gentamicin activity at extreme pH (up to 34.33 mm in <i>E. coli</i> and 33.5 mm in <i>P. aeruginosa</i>). In standard MH medium, the clinical <i>E</i>. <i>coli</i> isolate exhibited a 32.5-mm inhibition zone and a gentamicin minimum inhibitory concentration (MIC) of 4 µg/mL. Under urine-mimicking conditions, the inhibition zone decreased to 22.5 mm, while the MIC increased eightfold to 32 µg/mL, indicating a marked reduction in gentamicin efficacy under physiologically relevant urinary conditions. These findings demonstrate that environmental stress profoundly influences gentamicin efficacy and suggest that this effect may involve physiological adaptations, including RpoS-mediated stress responses, membrane remodeling, and osmoprotective mechanisms previously described in the literature.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 4","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70375","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148721702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbiome-Phytochemical Crosstalk Along the Gut-Brain Axis in Alzheimer and Parkinson's Disease","authors":"Md. Emon,&nbsp;Md. Mizanur Rahaman,&nbsp;Dhrubo Sarder,&nbsp;Md. Shadin,&nbsp;Shamima Akter Neela,&nbsp;Phurpa Wangchuk,&nbsp;Subir Sarker","doi":"10.1002/mbo3.70374","DOIUrl":"10.1002/mbo3.70374","url":null,"abstract":"<p>Gut-brain axis (GBA) has emerged as a bidirectional communication network linking the gut microbiota with central nervous system function and contributing to the pathogenesis of Alzheimer's disease (AD) and Parkinson's disease (PD). This study aimed to critically evaluate the current evidence on how phytochemicals modulate gut microbiota and GBA signaling to influence the progression of AD and PD. A systematic literature search was conducted using major scientific databases, and preclinical studies investigating microbiota-mediated mechanisms of phytochemicals were synthesized according to predefined inclusion criteria. The available evidence demonstrates that phytochemicals consistently remodel the gut microbiota by increasing beneficial taxa such as <i>Lactobacillus</i>, <i>Bifidobacterium</i>, <i>Akkermansia</i>, and short-chain fatty acid (SCFA)-producing bacteria while suppressing pro-inflammatory Gram-negative microorganisms. These microbial alterations were associated with reduced lipopolysaccharide (LPS) production, inhibition of TLR4/NF-κB and NLRP3 inflammasome signaling, enhancement of brain-derived neurotrophic factor (BDNF) activity, restoration of intestinal barrier integrity, attenuation of oxidative stress, and activation of autophagy-related pathways, including PI3K/AKT/mTOR and AMPK/mTOR, leading to reduced amyloid-β, tau, and α-synuclein pathology. A major contribution of this review is the integration of current evidence demonstrating the bidirectional crosstalk between phytochemicals and the gut microbiota as a central mechanism regulating GBA signaling in AD and PD. Available evidence suggests that phytochemical-mediated modulation of the gut microbiota represents a promising therapeutic strategy for slowing disease progression in AD and PD. However, further mechanistic investigations and well-designed clinical trials are required to validate these findings and facilitate their translation into clinical practice.</p>","PeriodicalId":18573,"journal":{"name":"MicrobiologyOpen","volume":"15 4","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.70374","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148725917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}