Pub Date : 2025-10-09DOI: 10.1016/j.micres.2025.128359
Tao Su , Qimiao Shi , Liyao Bai , Xueru Xu , Xueyan Li , Shanshan Li , Can Chen , Mengdie Hu
The two-component systems (TCSs) are crucial for bacterial adaptation to environmental stresses and growth conditions. In Corynebacterium glutamicum, a model organism of Corynebacteriales, 13 TCSs have been identified, but only five of them have been characterized previously. The ncgl0269-ncgl0268 gene cluster, annotated as a putative TCS (designated as CgtSR1), remains unexplored in terms of its regulatory role and mechanism. In this study, we revealed that CgtSR1 might regulate the expression of antimicrobial efflux transporters (including secondary transporters and primary transporters-ATP-binding cassette (ABC)) by transcriptomic analysis. EMSA experiments confirmed that CgtR1 directly binds to the promoter regions of three secondary transporter genes (ncgl0887, ncgl1020, and ncgl1445). Phenotypic assays demonstrated that the deletion of cgtSR1 increased susceptibility to gentamicin and spectinomycin, whereas its overexpression conferred resistance. Additionally, overexpression of cgtSR1 enhanced tolerance of cells to resorcinol and 2,4-dihydroxybenzoate. This study elucidates the regulatory network of CgtSR1 and deepens the understanding of TCS-mediated stress adaptation in C. glutamicum, providing a basis for further mechanistic investigations.
{"title":"Biologically functional and regulatory analysis of a two-component signal transduction system CgtSR1 in Corynebacterium glutamicum","authors":"Tao Su , Qimiao Shi , Liyao Bai , Xueru Xu , Xueyan Li , Shanshan Li , Can Chen , Mengdie Hu","doi":"10.1016/j.micres.2025.128359","DOIUrl":"10.1016/j.micres.2025.128359","url":null,"abstract":"<div><div>The two-component systems (TCSs) are crucial for bacterial adaptation to environmental stresses and growth conditions. In <em>Corynebacterium glutamicum</em>, a model organism of <em>Corynebacteriales</em>, 13 TCSs have been identified, but only five of them have been characterized previously. The <em>ncgl0269</em>-<em>ncgl0268</em> gene cluster, annotated as a putative TCS (designated as CgtSR1), remains unexplored in terms of its regulatory role and mechanism. In this study, we revealed that CgtSR1 might regulate the expression of antimicrobial efflux transporters (including secondary transporters and primary transporters-ATP-binding cassette (ABC)) by transcriptomic analysis. EMSA experiments confirmed that CgtR1 directly binds to the promoter regions of three secondary transporter genes (<em>ncgl0887</em>, <em>ncgl1020</em>, and <em>ncgl1445</em>). Phenotypic assays demonstrated that the deletion of <em>cgtSR1</em> increased susceptibility to gentamicin and spectinomycin, whereas its overexpression conferred resistance. Additionally, overexpression of <em>cgtSR1</em> enhanced tolerance of cells to resorcinol and 2,4-dihydroxybenzoate. This study elucidates the regulatory network of CgtSR1 and deepens the understanding of TCS-mediated stress adaptation in <em>C. glutamicum</em>, providing a basis for further mechanistic investigations.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"302 ","pages":"Article 128359"},"PeriodicalIF":6.9,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-08DOI: 10.1016/j.micres.2025.128360
Xinyu Zhou , Jun-Hu Cheng , Xiao Yang , Da-Wen Sun
Microbial contamination in food has long posed a significant global public health challenge. The growing antibiotic resistance of foodborne pathogens, particularly multidrug-resistant bacteria, has diminished the effectiveness of traditional antibiotic treatments and increased the public health burden. There is an urgent need for innovative strategies to control foodborne pathogenic bacteria and their resistance. Since the discovery of ferroptosis, a regulatory modality of cell death, researchers have advanced our understanding of its mechanisms. While ferroptosis is primarily observed in eukaryotic cells, some studies indicate that microbial cells also undergo a similar process. This ferroptosis-like death depends on the Fenton reaction and is triggered by iron overload, leading to excessive reactive oxygen species (ROS) and lipid peroxidation. However, current knowledge on ferroptosis-mediated control of foodborne pathogenic bacteria and antimicrobial resistance remains limited. Ferroptosis is primarily triggered by excess intracellular ferrous ions (Fe2+) and disruptions in antioxidant systems. Several studies have utilized this feature to design antimicrobial experiments, which have been successfully applied to antimicrobial infection treatment. Additionally, ferroptosis affects antibiotic-resistant bacteria mainly by inducing direct lethal effects through iron-dependent lipid peroxidation, and disrupting iron homeostasis, which bypasses traditional resistance mechanisms and enhances antibiotic efficacy. This review aims to summarize the concepts, mechanisms, and regulatory measures of ferroptosis while discussing its application in controlling pathogenic bacteria. Further insights into the specific molecular mechanisms of ferroptosis in foodborne pathogenic bacteria are essential to enhance inactivation precision and modulate antimicrobial resistance, thereby facilitating its practical application in food safety.
{"title":"Ferroptosis for food safety: An innovative and sustainable strategy in pathogenic bacteria inactivation and antimicrobial resistance modulation","authors":"Xinyu Zhou , Jun-Hu Cheng , Xiao Yang , Da-Wen Sun","doi":"10.1016/j.micres.2025.128360","DOIUrl":"10.1016/j.micres.2025.128360","url":null,"abstract":"<div><div>Microbial contamination in food has long posed a significant global public health challenge. The growing antibiotic resistance of foodborne pathogens, particularly multidrug-resistant bacteria, has diminished the effectiveness of traditional antibiotic treatments and increased the public health burden. There is an urgent need for innovative strategies to control foodborne pathogenic bacteria and their resistance. Since the discovery of ferroptosis, a regulatory modality of cell death, researchers have advanced our understanding of its mechanisms. While ferroptosis is primarily observed in eukaryotic cells, some studies indicate that microbial cells also undergo a similar process. This ferroptosis-like death depends on the Fenton reaction and is triggered by iron overload, leading to excessive reactive oxygen species (ROS) and lipid peroxidation. However, current knowledge on ferroptosis-mediated control of foodborne pathogenic bacteria and antimicrobial resistance remains limited. Ferroptosis is primarily triggered by excess intracellular ferrous ions (Fe<sup>2+</sup>) and disruptions in antioxidant systems. Several studies have utilized this feature to design antimicrobial experiments, which have been successfully applied to antimicrobial infection treatment. Additionally, ferroptosis affects antibiotic-resistant bacteria mainly by inducing direct lethal effects through iron-dependent lipid peroxidation, and disrupting iron homeostasis, which bypasses traditional resistance mechanisms and enhances antibiotic efficacy. This review aims to summarize the concepts, mechanisms, and regulatory measures of ferroptosis while discussing its application in controlling pathogenic bacteria. Further insights into the specific molecular mechanisms of ferroptosis in foodborne pathogenic bacteria are essential to enhance inactivation precision and modulate antimicrobial resistance, thereby facilitating its practical application in food safety.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"303 ","pages":"Article 128360"},"PeriodicalIF":6.9,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145459161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-08DOI: 10.1016/j.micres.2025.128358
Haoyuan Ding , Zehua Zheng , Peherden Ahat , Wei Song , Yibei Zhang , Qiyao Wang
Pseudomonas plecoglossicida is an important pathogen causing diseases in various fish including large yellow croaker leading to severe economic losses. Type VI secretion system (T6SS) has been established essential for its invasion and colonization in hosts, but the mechanism underlying regulation of virulence gene expression in vivo in physical conditions is still lacking. In this study, we identified that histidine kinase PvgS and response regulator PvgA consist a cognate two-component system (TCS) that has been established to regulate expression of key virulence genes including T6SS-1. Chromatin immuno-precipitation sequencing (ChIP-seq) technology, qRT-PCR and electrophoretic mobility shift assay (EMSA) revealed the specific PvgA binding Logos present in the ∼106 genes directly controlled by PvgA in P. plecoglossicida. Structural models of PvgS bound to Na+ and K+ ions and mutation analysis indicated that PvgS mediated an osmolality dependent virulence gene expression, i.e. T6SS-1 and pvgAS. PvgAS switch T6SS-1 expression by responding to different osmolality of Na+, K+, or Li+, but not sucrose. Moreover, we showed distinct roles of osmolality and temperature in the hierarchical regulatory mechanism to control the virulence gene expression in P. plecoglossicida, i.e. while temperature synergistically affects the T6SS-1 secretion at low osmotic environment, osmotic pressure dominates the expression of T6SS-1 at both high and low temperatures. Taken together, our study provided a new paradigm for PvgAS mediated virulence gene expression in P. plecoglossicida by responding to ion mediated osmolality variations, and facilitated the understanding of its in vivo and in vitro lifestyle switching and bacterial pathogenesis.
{"title":"The two-component system PvgAS orchestrates virulence gene expression in response to osmolality in Pseudomonas plecoglossicida","authors":"Haoyuan Ding , Zehua Zheng , Peherden Ahat , Wei Song , Yibei Zhang , Qiyao Wang","doi":"10.1016/j.micres.2025.128358","DOIUrl":"10.1016/j.micres.2025.128358","url":null,"abstract":"<div><div><em>Pseudomonas plecoglossicida</em> is an important pathogen causing diseases in various fish including large yellow croaker leading to severe economic losses. Type VI secretion system (T6SS) has been established essential for its invasion and colonization in hosts, but the mechanism underlying regulation of virulence gene expression <em>in vivo</em> in physical conditions is still lacking. In this study, we identified that histidine kinase PvgS and response regulator PvgA consist a cognate two-component system (TCS) that has been established to regulate expression of key virulence genes including T6SS-1. Chromatin immuno-precipitation sequencing (ChIP-seq) technology, qRT-PCR and electrophoretic mobility shift assay (EMSA) revealed the specific PvgA binding Logos present in the ∼106 genes directly controlled by PvgA in <em>P. plecoglossicida</em>. Structural models of PvgS bound to Na<sup>+</sup> and K<sup>+</sup> ions and mutation analysis indicated that PvgS mediated an osmolality dependent virulence gene expression, i.e. T6SS-1 and <em>pvgAS</em>. PvgAS switch T6SS-1 expression by responding to different osmolality of Na<sup>+</sup>, K<sup>+</sup>, or Li<sup>+</sup>, but not sucrose. Moreover, we showed distinct roles of osmolality and temperature in the hierarchical regulatory mechanism to control the virulence gene expression in <em>P. plecoglossicida</em>, i.e. while temperature synergistically affects the T6SS-1 secretion at low osmotic environment, osmotic pressure dominates the expression of T6SS-1 at both high and low temperatures. Taken together, our study provided a new paradigm for PvgAS mediated virulence gene expression in <em>P. plecoglossicida</em> by responding to ion mediated osmolality variations, and facilitated the understanding of its <em>in vivo</em> and <em>in vitro</em> lifestyle switching and bacterial pathogenesis.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"302 ","pages":"Article 128358"},"PeriodicalIF":6.9,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145266975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-01DOI: 10.1016/j.micres.2025.128357
Francisco Javier Marcos-Torres, Juana Pérez, David Torrens-González, Miguel Ángel García-Pedrosa, Francisco Javier Contreras-Moreno, Aurelio Moraleda-Muñoz
Copper accumulation in agricultural soils poses environmental challenges by selecting copper-resistant bacteria and also contributing to the co-selection of antibiotic-resistant bacteria. In addition, copper influences bacterial predator-prey interactions, potentially altering microbial ecosystems. Myxococcus xanthus, a soil-dwelling bacterium, preys on other microorganisms, including Sinorhizobium meliloti, a symbiotic nitrogen-fixing bacterium associated with leguminous plants. The role of copper in M. xanthus interactions remains poorly understood, although it accumulates at the predator-prey interface. In this study, we explore the transcriptomic response of M. xanthus to copper stress in both monocultures and co-cultures with S. meliloti. Our analysis identified many myxobacterial copper-regulated transcripts, and studies on mutant strains in some copper-induced genes revealed the role of two efflux pumps in cross-resistance to copper and tetracyclines. These findings provide new insights into the adaptive mechanisms of M. xanthus in response to copper, with implications for the co-selection of antibiotic resistance and the broader impact of copper on microbial community dynamics in soil ecosystems.
{"title":"Global copper response of the soil bacterial predator Myxococcus xanthus and its contribution to antibiotic cross-resistance","authors":"Francisco Javier Marcos-Torres, Juana Pérez, David Torrens-González, Miguel Ángel García-Pedrosa, Francisco Javier Contreras-Moreno, Aurelio Moraleda-Muñoz","doi":"10.1016/j.micres.2025.128357","DOIUrl":"10.1016/j.micres.2025.128357","url":null,"abstract":"<div><div>Copper accumulation in agricultural soils poses environmental challenges by selecting copper-resistant bacteria and also contributing to the co-selection of antibiotic-resistant bacteria. In addition, copper influences bacterial predator-prey interactions, potentially altering microbial ecosystems. <em>Myxococcus xanthus</em>, a soil-dwelling bacterium, preys on other microorganisms, including <em>Sinorhizobium meliloti</em>, a symbiotic nitrogen-fixing bacterium associated with leguminous plants. The role of copper in <em>M. xanthus</em> interactions remains poorly understood, although it accumulates at the predator-prey interface. In this study, we explore the transcriptomic response of <em>M. xanthus</em> to copper stress in both monocultures and co-cultures with <em>S. meliloti</em>. Our analysis identified many myxobacterial copper-regulated transcripts, and studies on mutant strains in some copper-induced genes revealed the role of two efflux pumps in cross-resistance to copper and tetracyclines. These findings provide new insights into the adaptive mechanisms of <em>M. xanthus</em> in response to copper, with implications for the co-selection of antibiotic resistance and the broader impact of copper on microbial community dynamics in soil ecosystems.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"302 ","pages":"Article 128357"},"PeriodicalIF":6.9,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145251443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-30DOI: 10.1016/j.micres.2025.128355
Jun Zhang , Xiaobing Zhou , Xiaoying Rong , Benfeng Yin , Lei Zhang , Yuanming Zhang
Phyllosphere microorganisms play a vital role in enhancing the adaptability and functionality of their host plants. Although the effects of phyllosphere microbial communities on host functional traits and their association with host phylogeny has been widely investigated, it remains unclear whether host selection consistently drives the assembly of these communities. In this study, bacterial and fungal communities on the surfaces of 734 leaf samples were characterized using bacterial and fungal amplicon sequencing. These microbial communities were associated with 42 plant species native to the Gurbantunggut Desert, a representative temperate desert located in Central Asia. The research assessed the relative contributions of plant-related factors, abiotic environmental variables (such as climate and soil), and spatial components to the observed variation in phyllosphere microbial communities, and further inferred the topological structure of plant-microbe interaction networks. The results indicate that plant phylogeny, plant functional traits, abiotic environment conditions, and spatial factors account for variations in the bacterial community composition (36.4 %, 4.6 %, 1.0 %, and 0.1 %, respectively) and the fungal community composition (28.6 %, 3.0 %, 1.5 %, and 1.2 %, respectively), following a hierarchical trend of plant phylogeny > plant functional traits > abiotic environment > space. Plant phylogeny and functional traits play a central role in shaping the assembly of phyllosphere microbial communities, indicating that plant filtering effects significantly influence microbial composition. Analysis of plant-microbe interactions reveals distinct preferences of microbial taxa for plant hosts across different taxonomic levels and geographic regions. Bipartite network analysis further illustrates that plant-microbe networks are highly specialized and modular, with plant-fungal networks exhibiting greater host specificity compared to plant-bacterial networks. Collectively, these findings underscore plant filtering as the primary determinant of microbial community assembly in the desert phyllosphere and provide valuable insights into the macroecological patterns shaping plant-microbe interactions in arid ecosystems.
{"title":"Host phylogeny and traits shape the composition and network structure of the phyllosphere microbial communities in temperate desert plants","authors":"Jun Zhang , Xiaobing Zhou , Xiaoying Rong , Benfeng Yin , Lei Zhang , Yuanming Zhang","doi":"10.1016/j.micres.2025.128355","DOIUrl":"10.1016/j.micres.2025.128355","url":null,"abstract":"<div><div>Phyllosphere microorganisms play a vital role in enhancing the adaptability and functionality of their host plants. Although the effects of phyllosphere microbial communities on host functional traits and their association with host phylogeny has been widely investigated, it remains unclear whether host selection consistently drives the assembly of these communities. In this study, bacterial and fungal communities on the surfaces of 734 leaf samples were characterized using bacterial and fungal amplicon sequencing. These microbial communities were associated with 42 plant species native to the Gurbantunggut Desert, a representative temperate desert located in Central Asia. The research assessed the relative contributions of plant-related factors, abiotic environmental variables (such as climate and soil), and spatial components to the observed variation in phyllosphere microbial communities, and further inferred the topological structure of plant-microbe interaction networks. The results indicate that plant phylogeny, plant functional traits, abiotic environment conditions, and spatial factors account for variations in the bacterial community composition (36.4 %, 4.6 %, 1.0 %, and 0.1 %, respectively) and the fungal community composition (28.6 %, 3.0 %, 1.5 %, and 1.2 %, respectively), following a hierarchical trend of plant phylogeny > plant functional traits > abiotic environment > space. Plant phylogeny and functional traits play a central role in shaping the assembly of phyllosphere microbial communities, indicating that plant filtering effects significantly influence microbial composition. Analysis of plant-microbe interactions reveals distinct preferences of microbial taxa for plant hosts across different taxonomic levels and geographic regions. Bipartite network analysis further illustrates that plant-microbe networks are highly specialized and modular, with plant-fungal networks exhibiting greater host specificity compared to plant-bacterial networks. Collectively, these findings underscore plant filtering as the primary determinant of microbial community assembly in the desert phyllosphere and provide valuable insights into the macroecological patterns shaping plant-microbe interactions in arid ecosystems.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"302 ","pages":"Article 128355"},"PeriodicalIF":6.9,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145244386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lipid metabolism is essential for maintaining cellular homeostasis and human health, and its dysregulation can contribute to metabolic disorders such as obesity and diabetes. As one of the most prevalent RNA modifications, the N6-methyladenosine (m6A) modification plays a pivotal role in regulating gene expression and metabolic pathways. The gut microbiota influences lipid metabolism by modulating the host's m6A modification patterns. Research has shown that the gut microbiota can regulate the levels of the m6A modification in host tissues, while the m6A modification also impacts the composition and functionality of the gut microbiota. This review comprehensively examines the interaction between the m6A modification and the gut microbiota, elucidating its underlying mechanisms in lipid metabolism and highlighting the potential applications of this crosstalk in addressing metabolic diseases. Future investigations should aim to further elucidate the precise molecular mechanisms governing the interplay between the m6A modification and the gut microbiota, thereby providing novel therapeutic targets and strategies for metabolic disease management.
{"title":"Crosstalk between the m6A modification and the gut microbiota in lipid metabolism","authors":"Haiyan Chen, Yaolin Ren, Jie Yu, Jing Ren, Yuan Zeng, Yifan Wu, Qian Zhang, Xinhua Xiao","doi":"10.1016/j.micres.2025.128356","DOIUrl":"10.1016/j.micres.2025.128356","url":null,"abstract":"<div><div>Lipid metabolism is essential for maintaining cellular homeostasis and human health, and its dysregulation can contribute to metabolic disorders such as obesity and diabetes. As one of the most prevalent RNA modifications, the N6-methyladenosine (m6A) modification plays a pivotal role in regulating gene expression and metabolic pathways. The gut microbiota influences lipid metabolism by modulating the host's m6A modification patterns. Research has shown that the gut microbiota can regulate the levels of the m6A modification in host tissues, while the m6A modification also impacts the composition and functionality of the gut microbiota. This review comprehensively examines the interaction between the m6A modification and the gut microbiota, elucidating its underlying mechanisms in lipid metabolism and highlighting the potential applications of this crosstalk in addressing metabolic diseases. Future investigations should aim to further elucidate the precise molecular mechanisms governing the interplay between the m6A modification and the gut microbiota, thereby providing novel therapeutic targets and strategies for metabolic disease management.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"302 ","pages":"Article 128356"},"PeriodicalIF":6.9,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145220713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-26DOI: 10.1016/j.micres.2025.128354
Carla García , Luis Saralegui , Beatriz Morales , Paula Jurado , M. Teresa Bes , Clara Marín , Jesús Arenas
Streptococcus suis is a zoonotic pathogen that affects pigs and humans. In this study, we characterised ShgH, a predicted substrate-binding component of an ABC transporter. Immunoassays confirmed that ShgH is expressed, secreted and surface-exposed in S. suis, in agreement with its proposed transporter function. Isothermal titration calorimetry demonstrated that ShgH binds glutamine and histidine, with a higher affinity for histidine. Deletion of the shgH gene significantly impaired uptake of both radiolabelled amino acids confirming its role as part of a transporter. Functional analysis revealed that shgH deletion results in a marked reduction in virulence in a murine infection model, while host colonization remained unaffected. ShgH contributes to infection by facilitating evasion of phagocytosis and resistance to oxidative stress through impaired nutrient acquisition and reduced capsule production. In addition, ShgH regulates biofilm formation and architecture. Notably, ShgH is highly conserved among pathogenic streptococci, suggesting a broader functional relevance. Altogether, our findings identify ShgH as a dual glutamine/histidine- binding protein essential for nutrient uptake and virulence in S. suis, and a promising target for future therapeutic interventions.
{"title":"Identification of ShgH as a dual histidine/glutamine transporter component essential for Streptococcus suis virulence and biofilm modulation","authors":"Carla García , Luis Saralegui , Beatriz Morales , Paula Jurado , M. Teresa Bes , Clara Marín , Jesús Arenas","doi":"10.1016/j.micres.2025.128354","DOIUrl":"10.1016/j.micres.2025.128354","url":null,"abstract":"<div><div><em>Streptococcus suis</em> is a zoonotic pathogen that affects pigs and humans. In this study, we characterised ShgH, a predicted substrate-binding component of an ABC transporter. Immunoassays confirmed that ShgH is expressed, secreted and surface-exposed in <em>S. suis,</em> in agreement with its proposed transporter function. Isothermal titration calorimetry demonstrated that ShgH binds glutamine and histidine, with a higher affinity for histidine. Deletion of the <em>shgH</em> gene significantly impaired uptake of both radiolabelled amino acids confirming its role as part of a transporter. Functional analysis revealed that <em>shgH</em> deletion results in a marked reduction in virulence in a murine infection model, while host colonization remained unaffected. ShgH contributes to infection by facilitating evasion of phagocytosis and resistance to oxidative stress through impaired nutrient acquisition and reduced capsule production. In addition, ShgH regulates biofilm formation and architecture. Notably, ShgH is highly conserved among pathogenic streptococci, suggesting a broader functional relevance. Altogether, our findings identify ShgH as a dual glutamine/histidine- binding protein essential for nutrient uptake and virulence in <em>S. suis</em>, and a promising target for future therapeutic interventions.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"302 ","pages":"Article 128354"},"PeriodicalIF":6.9,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145213105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The difficulty of accurately identifying Candidozyma auris (formerly Candida auris) and the high resistance rates presented have increased the concern in the healthcare setting. Due to this, the aim of this study was to analyse the fungal response to oxidative stress. To achieve this goal, gene and protein expression were examined using qPCR and two-dimensional electrophoresis, respectively, peroxiredoxin Tsa1b being found to be upregulated under oxidative stress. Subsequently, the significance of Tsa1b was next investigated by characterizing the C. auris Δtsa1b and C. auris Δtsa1b::TSA1B strains generated by CRISPR-Cas9. The findings demonstrated that the Δtsa1b strain was more susceptible to oxidative and cell wall stressors than the wild-type strain, which was consistent with an increase in the cell wall β-glucan amounts when grown in the presence of oxidative stress. Importantly, Tsa1b has also been detected as an antigen by patient sera. Furthermore, the Δtsa1b strain was also more vulnerable to the presence of dendritic cells and bone marrow-derived macrophages. Finally, in vivo infections performed in Galleria mellonella and mice showed a slower progression of the disease in animals infected with the mutant strain. In conclusion, the peroxiredoxin Tsa1b has been identified as a potential candidate to be studied as a virulence factor implicated in the oxidative stress response of C. auris. These findings advance the knowledge of the pathobiology of C. auris and point out the potential of Tsa1b for the development of new diagnostic and therapeutic approaches.
{"title":"The oxidative stress-related peroxiredoxin Tsa1b of Candidozyma (Candida) auris contributes to virulence and infection","authors":"Maialen Areitio , Oier Rodriguez-Erenaga , Leire Aparicio-Fernandez , Lucía Abio-Dorronsoro , Leire Martin-Souto , Uxue Perez-Cuesta , Idoia Buldain , Beñat Zaldibar , Alba Ruiz-Gaitan , Javier Pemán , Salomé LeibundGut-Landmann , Aitor Rementeria , Aitziber Antoran , Andoni Ramirez-Garcia","doi":"10.1016/j.micres.2025.128353","DOIUrl":"10.1016/j.micres.2025.128353","url":null,"abstract":"<div><div>The difficulty of accurately identifying <em>Candidozyma auris</em> (formerly <em>Candida auris</em>) and the high resistance rates presented have increased the concern in the healthcare setting. Due to this, the aim of this study was to analyse the fungal response to oxidative stress. To achieve this goal, gene and protein expression were examined using qPCR and two-dimensional electrophoresis, respectively, peroxiredoxin Tsa1b being found to be upregulated under oxidative stress. Subsequently, the significance of Tsa1b was next investigated by characterizing the <em>C. auris</em> Δ<em>tsa1b</em> and <em>C. auris</em> Δ<em>tsa1b::TSA1B</em> strains generated by CRISPR-Cas9. The findings demonstrated that the Δ<em>tsa1b</em> strain was more susceptible to oxidative and cell wall stressors than the wild-type strain, which was consistent with an increase in the cell wall β-glucan amounts when grown in the presence of oxidative stress. Importantly, Tsa1b has also been detected as an antigen by patient sera. Furthermore, the Δ<em>tsa1b</em> strain was also more vulnerable to the presence of dendritic cells and bone marrow-derived macrophages. Finally, <em>in vivo</em> infections performed in <em>Galleria mellonella</em> and mice showed a slower progression of the disease in animals infected with the mutant strain. In conclusion, the peroxiredoxin Tsa1b has been identified as a potential candidate to be studied as a virulence factor implicated in the oxidative stress response of <em>C. auris</em>. These findings advance the knowledge of the pathobiology of <em>C. auris</em> and point out the potential of Tsa1b for the development of new diagnostic and therapeutic approaches.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"302 ","pages":"Article 128353"},"PeriodicalIF":6.9,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145206891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-25DOI: 10.1016/j.micres.2025.128348
Nan Xu, Xiaojing Yang, Chenghao Li, Chen Zhang, Minliang Guo
Phenolic acids influence host-pathogen interactions and function as key signals in Agrobacterium-mediated transformation or plant-microbe symbiosis. Agrobacterium tumefaciens uses chemotaxis to detect plant-secreted phenolic compounds and migrates to infection sites, though the chemotactic mechanism remains unclear. In this study, starting with structurally simple phenolic acids, the chemotactic response of A. tumefaciens C58 was investigated. The chemotaxis of A. tumefaciens toward 4-hydroxybenzoate and protocatechuate is not impacted by the methyl-accepting chemotaxis proteins (MCPs) Atu0387 and Atu0738, which share a four-helix bundle domain with previously discovered phenolic-sensing MCPs. To identify chemoreceptors for phenolic acids, a heterologous expression and functional screening system was constructed in Escherichia coli. Among the 13 MCPs, Atu0872 could respond to both 4-hydroxybenzoate and protocatechuate. Furthermore, atu0872 deletion weakened chemotaxis toward vanillin, acetosyringone, guaiacol, caffeic, vanillic, salicylic, gallic, p-coumaric, syringic, and sinapinic acids. Although the ligand-binding domain of Atu0872 was predicted to be a nitrate- and nitrite-sensing domain, the A. tumefaciens deletion mutant Δatu0872 did not affect chemotaxis toward nitrate and nitrite. In addition to chemotaxis, atu0872 deletion decreased the tumor weight on Daucus carota roots, Kalanchoe daigremontiana leaves, and the number of bacterial colonies per 0.1 g of tumor, implying that atu0872 affects bacterial colonization on the host by regulating chemotactic behavior. To our knowledge, this is for the first study identifying Atu0872 as a core chemoreceptor in A. tumefaciens for phenolic compounds, providing a theoretical foundation for elucidating the chemotaxis–pathogenicity relationship in A. tumefaciens and optimizing its use in genetic transformations.
{"title":"Identification and functional characterization of chemoreceptors for phenolic acids in Agrobacterium tumefaciens","authors":"Nan Xu, Xiaojing Yang, Chenghao Li, Chen Zhang, Minliang Guo","doi":"10.1016/j.micres.2025.128348","DOIUrl":"10.1016/j.micres.2025.128348","url":null,"abstract":"<div><div>Phenolic acids influence host-pathogen interactions and function as key signals in <em>Agrobacterium</em>-mediated transformation or plant-microbe symbiosis. <em>Agrobacterium tumefaciens</em> uses chemotaxis to detect plant-secreted phenolic compounds and migrates to infection sites, though the chemotactic mechanism remains unclear. In this study, starting with structurally simple phenolic acids, the chemotactic response of <em>A. tumefaciens</em> C58 was investigated. The chemotaxis of <em>A. tumefaciens</em> toward 4-hydroxybenzoate and protocatechuate is not impacted by the methyl-accepting chemotaxis proteins (MCPs) Atu0387 and Atu0738, which share a four-helix bundle domain with previously discovered phenolic-sensing MCPs. To identify chemoreceptors for phenolic acids, a heterologous expression and functional screening system was constructed in <em>Escherichia coli</em>. Among the 13 MCPs, Atu0872 could respond to both 4-hydroxybenzoate and protocatechuate. Furthermore, <em>atu0872</em> deletion weakened chemotaxis toward vanillin, acetosyringone, guaiacol, caffeic, vanillic, salicylic, gallic, <em>p</em>-coumaric, syringic, and sinapinic acids. Although the ligand-binding domain of Atu0872 was predicted to be a nitrate- and nitrite-sensing domain, the <em>A. tumefaciens</em> deletion mutant <em>Δatu0872</em> did not affect chemotaxis toward nitrate and nitrite. In addition to chemotaxis, <em>atu0872</em> deletion decreased the tumor weight on <em>Daucus carota</em> roots, <em>Kalanchoe daigremontiana</em> leaves, and the number of bacterial colonies per 0.1 g of tumor, implying that <em>atu0872</em> affects bacterial colonization on the host by regulating chemotactic behavior. To our knowledge, this is for the first study identifying Atu0872 as a core chemoreceptor in <em>A. tumefaciens</em> for phenolic compounds, providing a theoretical foundation for elucidating the chemotaxis–pathogenicity relationship in <em>A. tumefaciens</em> and optimizing its use in genetic transformations.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"302 ","pages":"Article 128348"},"PeriodicalIF":6.9,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145213127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-24DOI: 10.1016/j.micres.2025.128349
Lingling Zhao , Hengqi He , Zhaohui Luo , Liwen Jin , Bo Xiao
Gut microbiota intricately regulate host cells through diverse mechanisms, with numerous pathways involving protein post-translational modifications (PTMs). This review comprehensively summarizes the impacts of the gut microbiota on various PTMs in host cells. It elaborates on how these modifications contribute to the development of host diseases, delving into mediating pathways, including changes in microbial metabolites, key enzymes, and the microenvironment. Conversely, it also explores how PTMs influence gut microbiota abundance. To overcome current research limitations, such as narrow perspectives and monotonous methods, novel strategies are proposed. Applying single-cell/spatial omics could reveal cell-type-specific and spatial PTM responses to microbial signals, while integrating AI algorithms with traditional experiments may predict PTM regulatory networks using microbial and host data. These strategies aim to expand research approaches and promote the clinical translation of findings in this field.
{"title":"Advances in the interaction between gut microbiota and post-translational modifications of proteins","authors":"Lingling Zhao , Hengqi He , Zhaohui Luo , Liwen Jin , Bo Xiao","doi":"10.1016/j.micres.2025.128349","DOIUrl":"10.1016/j.micres.2025.128349","url":null,"abstract":"<div><div>Gut microbiota intricately regulate host cells through diverse mechanisms, with numerous pathways involving protein post-translational modifications (PTMs). This review comprehensively summarizes the impacts of the gut microbiota on various PTMs in host cells. It elaborates on how these modifications contribute to the development of host diseases, delving into mediating pathways, including changes in microbial metabolites, key enzymes, and the microenvironment. Conversely, it also explores how PTMs influence gut microbiota abundance. To overcome current research limitations, such as narrow perspectives and monotonous methods, novel strategies are proposed. Applying single-cell/spatial omics could reveal cell-type-specific and spatial PTM responses to microbial signals, while integrating AI algorithms with traditional experiments may predict PTM regulatory networks using microbial and host data. These strategies aim to expand research approaches and promote the clinical translation of findings in this field.</div></div>","PeriodicalId":18564,"journal":{"name":"Microbiological research","volume":"302 ","pages":"Article 128349"},"PeriodicalIF":6.9,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145206902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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