Current Research in Microbial Sciences最新文献

{"title":"Pyricularia pennisetigena and Pyricularia oryzae isolates from Paraguay's wheat-growing regions and the impact on wheat","authors":"Cinthia Carolina Cazal-Martínez ,&nbsp;Yessica Magaliz Reyes-Caballero ,&nbsp;Alice Rocio Chávez ,&nbsp;Pastor Enmanuel Pérez-Estigarribia ,&nbsp;Man Mohan Kohli ,&nbsp;Alcides Rojas ,&nbsp;Andrea Alejandra Arrua ,&nbsp;Juliana Moura-Mendes ,&nbsp;Ramón Souza-Perera ,&nbsp;José Juan Zúñiga Agilar ,&nbsp;Emile Gluck-Thaler ,&nbsp;Horacio Lopez-Nicora ,&nbsp;Julio Cesar Masaru Iehisa","doi":"10.1016/j.crmicr.2025.100361","DOIUrl":"10.1016/j.crmicr.2025.100361","url":null,"abstract":"<div><div>The <em>Pyricularia</em> genus includes species causing blast disease in monocots, posing significant challenges for disease management due to their ability to infect multiple hosts. This study aimed to identify the pathogenicity and species identity of <em>Pyricularia</em> isolates from 11 plant species in wheat-growing regions of Paraguay and assess their capacity to infect wheat. Twenty-four monosporic isolates were analyzed based on macroscopic and microscopic and phylogenetic characteristics. Three phylogenetic clades corresponding to <em>P. oryzae, P. grisea</em>, and <em>P. pennisetigena</em> were identified through five barcoding genes. For the first time, wheat blast was reported in San Pedro Department, and blast disease was observed in weeds in Cordillera and Central Departments. In greenhouse trials, <em>P. oryzae</em> isolates from wheat successfully infected both susceptible and resistant wheat cultivars, whereas isolates from non-wheat hosts did not elicit symptoms. Notably, <em>P. pennisetigena</em> isolates derived from <em>Cenchrus echinatus</em> were capable of infecting wheat spikes, producing typical blast symptoms, highlighting the potential for cross-species pathogen transmission. This finding suggests <em>P. pennisetigena</em> may pose an emerging threat to wheat in Paraguay, as its primary host is prevalent near wheat fields. These results highlight the critical importance of integrated disease management strategies, particularly the identification of inoculum sources, to mitigate cross-species pathogen transmission. This approach aligns with the One Health paradigm by addressing interconnected risks to plant health, food security, and environmental sustainability.</div></div>","PeriodicalId":34305,"journal":{"name":"Current Research in Microbial Sciences","volume":"8 ","pages":"Article 100361"},"PeriodicalIF":4.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cooperative mechanisms of LexA and HtpG in the regulation of virulence gene expression in Pseudomonas plecoglossicida","authors":"Rongchao He ,&nbsp;Yanfei Zuo ,&nbsp;Qiu Li ,&nbsp;Qingpi Yan ,&nbsp;Lixing Huang","doi":"10.1016/j.crmicr.2025.100351","DOIUrl":"10.1016/j.crmicr.2025.100351","url":null,"abstract":"<div><div>LexA is a well-known transcriptional repressor of DNA repair genes induced by DNA damage in <em>Escherichia coli</em> and other bacterial species. Recently, this paradigm—that LexA solely regulates the SOS response—has been challenged as studies reveal its involvement in various biological functions linked to virulence. <em>Pseudomonas plecoglossicida</em>, a major pathogen in mariculture, causes substantial economic losses annually in China. Our previous research suggested that LexA might collaboratively regulate virulence gene expression with HtpG during infection. This study aims to elucidate the molecular mechanism by which LexA controls virulence gene expression. We employed an array of methods including molecular dynamics simulations, molecular docking, ChIP-seq, RNA-seq, mass spectrometry, gene mutagenesis, LacZ reporter assays, electrophoretic mobility shift assays, co-immunoprecipitation, and in vitro LexA degradation experiments. Our findings identified 36 downstream virulence genes regulated by LexA, define three critical LexA binding motifs, and provide an in-depth analysis of LexA's recognition and binding to promoters, thereby regulating virulence gene expression. Additionally, we confirm the cooperative regulatory roles of HtpG, RecA, and LexA in virulence gene modulation. This is the first report of an endogenous accessory factor aiding in the binding of LexA to DNA. This study enhances our understanding of LexA's role in virulence regulation and offers a valuable theoretical and practical foundation for disease prevention and control.</div></div>","PeriodicalId":34305,"journal":{"name":"Current Research in Microbial Sciences","volume":"8 ","pages":"Article 100351"},"PeriodicalIF":4.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143105057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of synergistic fermentation of tea bee pollen with bacteria and enzymes on growth and intestinal health of Apis cerana cerana","authors":"Panpan Xue ,&nbsp;Le Xu ,&nbsp;Yakai Tian ,&nbsp;Mingkui Lv ,&nbsp;Pingping Fang ,&nbsp;Kun Dong ,&nbsp;Qiuye Lin ,&nbsp;Zhenhui Cao","doi":"10.1016/j.crmicr.2025.100343","DOIUrl":"10.1016/j.crmicr.2025.100343","url":null,"abstract":"<div><div>While the health benefits of lactic acid bacteria (LAB)-fermented feed on farmed animals are well-established, its potential benefits for honeybees, specifically <em>Apis cerana cerana</em>, remain largely unexplored. The present study aimed to optimize an enzymatic hydrolysis process for tea bee pollen, employing a complex enzyme comprising acid cellulase and pectinase, followed by fermentation with <em>Limosilactobacillus reuteri</em> LP4. <em>A. c. cerana</em> workers were subsequently fed tea bee pollen processed with this optimized method. Under the optimal processing condition of fermented tea bee pollen, the pH value was 4.41, the protein content was 27.75 %, and the viable count of LAB was 2.31×10⁹ CFU/g. No molds and yeasts as well as pathogens were detected. Compared to the unfermented pollen, honey bee workers administrated with fermented tea pollen with L. <em>reuteri</em> LP4 showed significantly increased survival rate by 24.34 % on day 15. Moreover, the relative abundances of <em>Lactobacillus</em> and <em>Bifidobacterium</em> were elevated, while those of <em>Enterococcus</em> and <em>Bacteroides</em> were diminished. Concurrently, the relative expression levels of immune-related genes including <em>Abaecin, PPO, Defensin</em>, and <em>Vg</em> were significantly upregulated. These findings provide a scientific foundation for application of fermented feeds to enhance the health of <em>A. c. cerana</em> populations and contribute to the sustainable development of apiculture in China.</div></div>","PeriodicalId":34305,"journal":{"name":"Current Research in Microbial Sciences","volume":"8 ","pages":"Article 100343"},"PeriodicalIF":4.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143105136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel mode of histone-like protein HupB regulating Sinorhizobium meliloti cell division through lysine acetylation","authors":"Ningning Li ,&nbsp;Huibo Jin ,&nbsp;Hongbo Li ,&nbsp;Huilin Yu ,&nbsp;Xiaoxu Wu ,&nbsp;Tianci Zhang ,&nbsp;Liangliang Yu ,&nbsp;Zhaoling Qin ,&nbsp;Li Luo","doi":"10.1016/j.crmicr.2025.100345","DOIUrl":"10.1016/j.crmicr.2025.100345","url":null,"abstract":"<div><div>HU, a small, basic histone-like protein, binds to bacterial genomic DNA, influencing DNA conformation, replication, and transcription. Its acetylation is a key post-translational modification affecting its DNA-binding activity. The role of HU acetylation in regulating cell division through the cell cycle regulatory system remained largely unknown. In this study, we find that stimulation of lysine acetylation or non-acetylation in HupB, a homolog of HU, differentially regulates the expression of cell cycle regulators, as well as cell growth and division in <em>Sinorhizobium meliloti</em>. Lys3, Lys13, and Lys83 in HupB were identified as acetylated residues by mass spectrometry. Mutating these residues to arginine (stimulating non-acetylation) in HupB impedes normal cell division, while substituting them with glycine (mimicking acetylation) allows for rapid cell duplication. The mimicry of non-acetylated HupB leads to enlarged abnormal cells, while stimulating acetylated HupB only reduces cell length. Transcription activation was observed in the mutant cells. Cell cycle regulators such as CtrA, GcrA and DnaA were differentially expressed in the mutants. HupB substitutions differentially bound to these cell cycle regulatory genes. These findings suggest that the appropriate acetylation of HupB regulates the expression of cell cycle regulators, thereby controlling <em>S. meliloti</em> cell division.</div></div>","PeriodicalId":34305,"journal":{"name":"Current Research in Microbial Sciences","volume":"8 ","pages":"Article 100345"},"PeriodicalIF":4.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143105138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-omics unveils strain-specific neuroactive metabolite production linked to inflammation modulation by Bacteroides and their extracellular vesicles","authors":"Basit Yousuf ,&nbsp;Walid Mottawea ,&nbsp;Galal Ali Esmail ,&nbsp;Nazila Nazemof ,&nbsp;Nour Elhouda Bouhlel ,&nbsp;Emmanuel Njoku ,&nbsp;Yingxi Li ,&nbsp;Xu Zhang ,&nbsp;Zoran Minic ,&nbsp;Riadh Hammami","doi":"10.1016/j.crmicr.2025.100358","DOIUrl":"10.1016/j.crmicr.2025.100358","url":null,"abstract":"<div><div><em>Bacteroides</em> species are key members of the human gut microbiome and play crucial roles in gut ecology, metabolism, and host-microbe interactions. This study investigated the strain-specific production of neuroactive metabolites by 18 Bacteroidetes (12 <em>Bacteroides</em>, 4 <em>Phocaeicola</em>, and 2 <em>Parabacteroides</em>) using multi-omics approaches. Genomic analysis revealed a significant potential for producing GABA, tryptophan, tyrosine, and histidine metabolism-linked neuroactive compounds. Using untargeted and targeted metabolomics, we identified key neurotransmitter-related or precursor metabolites, including GABA, <span>l</span>-tryptophan, 5-HTP, normelatonin, kynurenic acid, <span>l</span>-tyrosine, and norepinephrine, in a strain- and media-specific manner, with GABA (1–2 mM) being the most abundant. Additionally, extracellular vesicles (EVs) produced by <em>Bacteroides</em> harbor multiple neuroactive metabolites, mainly GABA, and related key enzymes. We used CRISPR/Cas12a-based gene engineering to create a knockout mutant lacking the glutamate decarboxylase gene (<em>gadB</em>) to demonstrate the specific contribution of <em>Bacteroides finegoldii</em>-derived GABA in modulating intestinal homeostasis. Cell-free supernatants from wild-type (WT, GABA+) and Δ<em>gadB</em> (GABA-) provided GABA-independent reinforcement of epithelial membrane integrity in LPS-treated Caco-2/HT29-MTX co-cultures. EVs from WT and Δ<em>gadB</em> attenuated inflammatory immune response of LPS-treated RAW264.7 macrophages, with reduced pro-inflammatory cytokines (IL-1β and IL-6), downregulation of TNF-α, and upregulation of IL-10 and TGF-β. GABA production by <em>B. finegoldii</em> had a limited impact on gut barrier integrity but a significant role in modulating inflammation. This study is the first to demonstrate the presence of a myriad of neuroactive metabolites produced by <em>Bacteroides</em> species in a strain- and media-specific manner in supernatant and EVs, with GABA being the most dominant metabolite and influencing immune responses.</div></div>","PeriodicalId":34305,"journal":{"name":"Current Research in Microbial Sciences","volume":"8 ","pages":"Article 100358"},"PeriodicalIF":4.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification and characterization of amphipathic antimicrobial peptides with broad spectrum activity against multi-drug resistant bacteria.","authors":"Mireia López-Siles ,&nbsp;Ana Tajuelo ,&nbsp;Pau Caravaca-Fuentes ,&nbsp;Marta Planas ,&nbsp;Lidia Feliu ,&nbsp;Michael J. McConnell","doi":"10.1016/j.crmicr.2025.100363","DOIUrl":"10.1016/j.crmicr.2025.100363","url":null,"abstract":"<div><div>Antimicrobial peptides (AMPs) are potential alternatives to antibiotics given the reduced likelihood of resistance and their high selectivity towards bacteria. AMPs with activity against antibiotic-resistant bacteria have been reported. The aim of this study is to characterize the activity of novel <strong>BP100</strong> analogues against multidrug-resistant bacteria. Eleven bacterial strains representing five pathogenic species were used to evaluate the antimicrobial activity of 26 peptides. An initial screen was performed at 50 µg/ml, and those peptides that inhibited ≈90 % of growth of all strains were selected. Minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC), inhibition in biofilm formation, time kill assays, stability in human serum and <em>in vivo</em> toxicity were assessed. <strong>BP607, BP76</strong> and <strong>BP145,</strong> had broad activity against multidrug-resistant bacteria. MICs ranged between 3.13 and 50 µg/ml, whereas MBCs ranged between 6.25 and 100 µg/ml. <em>Acinetobacter baumannii, Klebsiella pneumoniae</em> and <em>Escherichia coli</em> were the most susceptible species. At 2x the MIC, all compounds were bactericidal after 6h. <strong>BP76</strong> inhibited ≥ 76.77 % of <em>K. pneumoniae</em> and <em>E. coli</em> biofilm formation at subinhibitory concentrations. <strong>BP145</strong> had improved serum stability and lower toxicity compared to <strong>BP607</strong>. In conclusion, <strong>BP145</strong> and <strong>BP76</strong> demonstrate broad antimicrobial activity, are active at non-toxic concentrations, feature bactericidal activity at 6h and inhibit biofilm formation.</div></div>","PeriodicalId":34305,"journal":{"name":"Current Research in Microbial Sciences","volume":"8 ","pages":"Article 100363"},"PeriodicalIF":4.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143463426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kingella kingae cytotoxin RtxA induces an innate immune response in oral epithelial cells","authors":"Eliska Ruzickova ,&nbsp;Karyna Zhuk ,&nbsp;Kevin Munoz Navarrete ,&nbsp;Adriana Osickova ,&nbsp;Radim Osicka","doi":"10.1016/j.crmicr.2025.100393","DOIUrl":"10.1016/j.crmicr.2025.100393","url":null,"abstract":"<div><div>The genus <em>Kingella</em> comprises four common species: the commensals <em>K. oralis</em> and <em>K. denitrificans</em>, the emerging paediatric pathogen <em>K. kingae</em> and the novel species <em>K. negevensis</em>. Improved diagnostic methods have led to the recognition of <em>K. kingae</em> as a major cause of septic arthritis in young children. The key virulence factor responsible for the pathogenesis of <em>K. kingae</em> is its cytotoxin RtxA, which is thought to facilitate host invasion. After binding to target cells, RtxA inserts into the host cell membrane and forms ion-conducting membrane pores that disrupt normal cell physiology and ultimately lead to cell death. In this study, we analysed the pro-inflammatory response of oral epithelial cells to a clinical isolate of <em>K. kingae</em>, its isogenic RtxA-deficient mutant and the commensals <em>K. oralis</em> and <em>K. denitrificans</em>, which do not produce RtxA. The results show that infection of cells with <em>K. kingae</em>, but not with the RtxA-deficient mutant and the commensal species, leads to increased expression and secretion of certain pro-inflammatory cytokines and chemokines. Furthermore, the RtxA-producing <em>K. kingae</em>, but not the RtxA-deficient mutant, upregulated the expression of <em>DEFB4A</em> and <em>SLPI</em> genes encoding antimicrobial peptides. These findings demonstrate that the RtxA toxin induces an innate immune response in oral epithelial cells.</div></div>","PeriodicalId":34305,"journal":{"name":"Current Research in Microbial Sciences","volume":"8 ","pages":"Article 100393"},"PeriodicalIF":4.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plant-derived nodule-specific cysteine-rich peptides as potent antifungal agents against Cryptococcus neoformans: mechanisms of action, chimeric peptide enhancement, and immunomodulatory effects","authors":"Bettina Szerencsés ,&nbsp;Csaba Papp ,&nbsp;Alexandra Pál ,&nbsp;Sándor Jenei ,&nbsp;Nelli Németh ,&nbsp;Csaba Vágvölgyi ,&nbsp;Ferhan Ayaydin ,&nbsp;Gabriella Endre ,&nbsp;Éva Kondorosi ,&nbsp;Ilona Pfeiffer","doi":"10.1016/j.crmicr.2025.100407","DOIUrl":"10.1016/j.crmicr.2025.100407","url":null,"abstract":"<div><div>The basidiomycetous yeast <em>Cryptococcus neoformans</em> is classified among the four critical fungal pathogens due to its capability of inducing life-threatening meningitis in immunocompromised individuals, particularly AIDS patients. The increasing prevalence of antifungal resistance and limitations of current treatments highlight the urgent need for novel therapeutic strategies. Antimicrobial peptides (AMPs), including plant-derived nodule-specific cysteine-rich (NCR) peptides, offer promising alternatives due to their broad-spectrum activity, multiple cellular targets, and minimal cytotoxic effects on mammalian cells. The aim of this study was to evaluate the anti-cryptococcal efficacy of NCR247, NCR335, NCR169C derivatives, and three synthetic chimeric peptides. Fifteen peptide derivatives and all three chimeras exhibited potent antifungal activity while demonstrating negligible cytotoxicity against murine macrophages. Among them, the X1-NCR247C chimera was the most effective, acting rapidly at low concentrations. Notably, its attachment to the yeast cells augmented the uptake of the cells by murine macrophages, suggesting that in addition to their direct fungicidal effects, antimicrobial peptides can intensify the immune response. These findings underscore the potential of NCR peptide derivatives as anti-cryptococcal agents and highlight the advantages of chimera peptides in improving therapeutic efficacy.</div></div>","PeriodicalId":34305,"journal":{"name":"Current Research in Microbial Sciences","volume":"9 ","pages":"Article 100407"},"PeriodicalIF":4.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144178560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Pseudomonas aeruginosa biofilm formation by different sequence types on treating lower limb vascular infections","authors":"Yudi Wang ,&nbsp;Qian Xiao ,&nbsp;Qiong Yang ,&nbsp;Yulin Long ,&nbsp;Zhibiao Jiang ,&nbsp;Tantao Zhang ,&nbsp;Ying Hu ,&nbsp;Bingru Gao ,&nbsp;Xuanyu Chen ,&nbsp;Ting Wang ,&nbsp;Linlin Xiao","doi":"10.1016/j.crmicr.2025.100379","DOIUrl":"10.1016/j.crmicr.2025.100379","url":null,"abstract":"<div><div><em>Pseudomonas aeruginosa</em> is a major contributor to persistent chronic infections in clinical practice, owing to its robust biofilm formation capacity and frequent antimicrobial resistance acquisition. However, most current studies focus on single strains and thus overlook phenotypic differences among coexisting strains within the same host. With that in mind, we proposed a hypothesis that <em>P. aeruginosa</em> strains from the same patient, yet with distinct genetic backgrounds, might exhibit differing resistance profiles and virulence genes. To test this hypothesis, we selected three strains with different sequence types (STs), all isolated from the chronic wounds of a patient with long-term bilateral lower limb infections. By employing multilocus sequence typing, antimicrobial susceptibility testing, biofilm gene quantification, growth kinetics assays, Galleria mellonella virulence experiments, and phylogenetic reconstruction, we systematically evaluated the relationships between these strains'biofilm formation and virulence. The results revealed significant genetic diversity and evolutionary origin variations among the three strains. Notably, ST2584 (WYDPA-23-3) exhibited multidrug resistance (resistant to 7 of the 12 tested antibiotics) and the highest growth rate, whereas ST270 (WYDPA-23-2)—despite the downregulation of <em>pelA</em>, a gene linked to extracellular matrix biogenesis—demonstrated a 2.3-fold increase in biofilm formation and the highest larval lethality. By comparing multiple strains coexisting in the same host, this study further elucidates the role of <em>P. aeruginosa</em> biofilm in sustaining chronic infections and offers valuable guidance for optimizing clinical treatment strategies and antibiotic selection. In light of these findings, developing rapid and precise biofilm detection methods and designing innovative drugs targeting high biofilm-producing strains should be prioritized.</div></div>","PeriodicalId":34305,"journal":{"name":"Current Research in Microbial Sciences","volume":"8 ","pages":"Article 100379"},"PeriodicalIF":4.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143895685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"L-serine-O-sulfate alters cellular ultrastructure and mitigates the capacity of biofilm formation in Streptococcus mutans UA159 via interfering with glutamate racemase","authors":"Jianying Zhang ,&nbsp;He-Ling Wang ,&nbsp;Tianyu Ding ,&nbsp;Yingjie Sun ,&nbsp;Shaotai Wang ,&nbsp;Chengcheng Yin","doi":"10.1016/j.crmicr.2025.100427","DOIUrl":"10.1016/j.crmicr.2025.100427","url":null,"abstract":"<div><div>Dental caries, primarily caused by <em>Streptococcus mutans</em> (<em>S. mutans</em>), remains a significant global health challenge. Conventional treatments often disrupt commensal oral flora, necessitating targeted antimicrobial strategies. This study investigated L‑serine-O-sulfate (LSOS), a substrate analog of glutamate racemase (MurI), as a potential agent for interfering with <em>S. mutans</em> UA159 virulence. Computational docking predicted LSOS binding to MurI, while circular dichroism spectroscopy confirmed LSOS-induced structural perturbations in recombinant MurI. LSOS exhibited concentration-dependent bactericidal effects, with 5.0 mM completely suppressing growth and 2.5 mM significantly extending doubling time (11.37 hrs vs. 5.68 hrs in controls). Transmission electron microscopy revealed progressive ultrastructural damage, characterized by membrane blebs and cell wall disintegration. Biofilm formation was severely impaired, with 63 % reduction in biomass and significant disruption of extracellular matrix integrity. Microarray-based gene expression analysis identified 119 differentially expressed genes, predominantly downregulated (111/119), affecting translation machinery, metabolic pathways, and transmembrane transport. Biosafety evaluation in L929 fibroblasts showed reduced proliferation (67.59 % of control at 2.5 mM after 48 hrs) with both G1-phase reduction and S-phase cell cycle accumulation. <em>Caenorhabditis elegans</em> demonstrated uncompromised survival and early development at concentrations &lt;10 mM, with developmental toxicity emerging only at higher doses (≥20 mM). These findings establish LSOS as a promising anti-virulence agent targeting MurI in <em>S. mutans</em> UA159, with favorable biosafety profiles that warrant further investigation for dental caries prevention and treatment.</div></div>","PeriodicalId":34305,"journal":{"name":"Current Research in Microbial Sciences","volume":"9 ","pages":"Article 100427"},"PeriodicalIF":4.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144471866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}