Journal of Bacteriology最新文献

{"title":"Defining the networks that connect RNase III and RNase J-mediated regulation of primary and specialized metabolism in <i>Streptomyces venezuelae</i>.","authors":"Meghan A D Pepler, Emma L Mulholland, Freddie R Montague, Marie A Elliot","doi":"10.1128/jb.00024-25","DOIUrl":"10.1128/jb.00024-25","url":null,"abstract":"<p><p>RNA metabolism involves coordinating RNA synthesis with RNA processing and degradation. Ribonucleases play fundamental roles within the cell, contributing to the cleavage, modification, and degradation of RNA molecules, with these actions ensuring appropriate gene regulation and cellular homeostasis. Here, we employed RNA sequencing to explore the impact of RNase III and RNase J on the transcriptome of <i>Streptomyces venezuelae</i>. Differential expression analysis comparing wild-type and RNase mutant strains at distinct developmental stages revealed significant changes in transcript abundance, particularly in pathways related to multicellular development, nutrient acquisition, and specialized metabolism. Both RNase mutants exhibited dysregulation of the BldD regulon, including altered expression of many cyclic-di-GMP-associated enzymes. We also observed precocious chloramphenicol production in these RNase mutants and found that in the RNase III mutant, this was associated with PhoP-mediated regulation. We further found that RNase III directly targeted members of the PhoP regulon, suggesting a link between RNA metabolism and a regulator that bridges primary and specialized metabolism. We connected RNase J function with translation through the observation that RNase J directly targets multiple ribosomal protein transcripts for degradation. These findings establish distinct but complementary roles for RNase III and RNase J in coordinating the gene expression dynamics critical for <i>S. venezuelae</i> development and specialized metabolism.</p><p><strong>Importance: </strong>RNA processing and metabolism are mediated by ribonucleases and are fundamental processes in all cells. In the morphologically complex and metabolically sophisticated <i>Streptomyces</i> bacteria, RNase III and RNase J influence both development and metabolism through poorly understood mechanisms. Here, we show that both ribonucleases are required for the proper expression of the BldD developmental pathway and contribute to the control of chloramphenicol production, with an interesting connection to phosphate regulation for RNase III. Additionally, we show that both RNases have the potential to impact translation through distinct mechanisms and can function cooperatively in degrading specific transcripts. This study advances our understanding of RNases in <i>Streptomyces</i> biology by providing insight into distinct contributions made by these enzymes and the intriguing interplay between them.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0002425"},"PeriodicalIF":2.7,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12096830/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143972528","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":"Iron-based microbial interactions: the role of iron metabolism in the cheese ecosystem.","authors":"Rina Mekuli, Mahtab Shoukat, Eric Dugat-Bony, Pascal Bonnarme, Sophie Landaud, Dominique Swennen, Vincent Hervé","doi":"10.1128/jb.00539-24","DOIUrl":"10.1128/jb.00539-24","url":null,"abstract":"<p><p>Iron is involved in various microbial metabolisms and interactions and is an essential micronutrient for most microorganisms. This review focuses on the cheese ecosystem, in which iron is sparse (median concentration of 2.9 mg/kg based on a literature survey) and of limited bioavailability due to the presence of various metal-binding agents in the cheese matrix. Cheese microorganisms overcome this low bioavailability of iron by producing and/or importing ferric iron-specific chelators called siderophores. We introduce these siderophores and their specific transporters, which play a key role in ecological interactions and microbial metabolism. We discuss the impact of iron on all the major taxa (fungi, bacteria, and viruses) and functional groups (starters, ripening microorganisms, and pathogens) present and interacting in cheese, from the community to individual levels. We describe the ways in which cheese-ripening microorganisms use iron and the effects of iron limitation on major metabolic pathways, including the tricarboxylic acid (TCA) cycle and amino-acid biosynthesis. The cheese ecosystem is a relevant <i>in situ</i> model for improving our understanding of iron biochemistry and its putative role in microbe-microbe interactions. Yet, this review highlights critical gaps in our understanding of iron's role in cheese from fundamental ecological and biochemical perspectives to applied microbiology, with broader implications for the quality, safety, and organoleptic properties of cheese.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0053924"},"PeriodicalIF":2.7,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12096840/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143982067","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":"Rapid screening and identification of genes involved in bacterial extracellular membrane vesicle production using a curvature-sensing peptide.","authors":"Hiromu Inoue, Kenichi Kawano, Jun Kawamoto, Takuya Ogawa, Tatsuo Kurihara","doi":"10.1128/jb.00497-24","DOIUrl":"10.1128/jb.00497-24","url":null,"abstract":"<p><p>Bacteria secrete extracellular membrane vesicles (EMVs). Physiological functions and biotechnological applications of these lipid nanoparticles have been attracting significant attention. However, the details of the molecular basis of EMV biogenesis have not yet been fully elucidated. In our previous work, an N-terminus-substituted FAAV peptide labeled with nitrobenzoxadiazole (NBD; nFAAV5-NBD) was developed. This peptide can sense the curvature of a lipid bilayer and selectively bind to EMVs even in the presence of cells. Here, we applied nFAAV5-NBD to a genome-wide screening of hyper- and hypo-vesiculation transposon mutants of a Gram-negative bacterium, <i>Shewanella vesiculosa</i> HM13, to identify the genes involved in EMV production. We analyzed the transposon insertion sites in hyper- and hypo-vesiculation mutants and identified 16 and six genes, respectively, with a transposon inserted within or near them. Targeted gene-disrupted mutants of the identified genes showed that the lack of putative dipeptidyl carboxypeptidase, glutamate synthase β-subunit, LapG protease, metallohydrolase, RNA polymerase sigma-54 factor, inactive transglutaminase, PepSY domain-containing protein, and Rhs-family protein caused EMV overproduction. On the other hand, disruption of the genes encoding putative phosphoenolpyruvate synthase, d-hexose-6-phosphate epimerase, NAD-specific glutamate dehydrogenase, and sensory box histidine kinase/response regulator decreased EMV production. This study demonstrates the utility of a novel screening method using a curvature-sensing peptide for mutants with altered EMV productivity and provides information on the genes related to EMV production.IMPORTANCEConventional methods for isolation and quantification of extracellular membrane vesicles (EMVs) are generally time-consuming. nFAAV5-NBD can detect EMVs in the culture without separating EMVs from cells. <i>In situ</i> detection of EMVs using this peptide facilitated screening of the genes related to EMV production. We succeeded in identifying various genes associated with EMV production of <i>Shewanella vesiculosa</i> HM13, which would contribute to the elucidation of bacterial EMV formation mechanisms. Additionally, the hyper-vesiculating mutants obtained in this study would be valuable for EMV applications, such as secreting useful substances as EMV cargoes and producing artificially functionalized EMVs.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0049724"},"PeriodicalIF":2.7,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12096838/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779953","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":"FleQ finetunes the expression of a subset of BrlR-activated genes to enable antibiotic tolerance by <i>Pseudomonas aeruginosa</i> biofilms.","authors":"Victoria I Oladosu, Karin Sauer","doi":"10.1128/jb.00503-24","DOIUrl":"10.1128/jb.00503-24","url":null,"abstract":"<p><p>The transcriptional regulator FleQ contributes to <i>Pseudomonas aeruginosa</i> biofilm formation by activating the expression and biosynthesis of matrix exopolysaccharides in a manner dependent on c-di-GMP. However, little is known about the role of FleQ in the antibiotic tolerance phenotype of <i>P. aeruginosa</i> biofilms. Inactivation of <i>fleQ</i> impaired biofilm formation and rendered biofilms susceptible to tobramycin and norfloxacin. The phenotypes were similar to biofilms inactivated in <i>sagS</i> encoding the orphan sensor SagS that promotes the switch from planktonic to biofilm growth via BfiSR and antibiotic tolerance via BrlR. While FleQ was found to contribute to biofilm formation independently of SagS and BfiSR, FleQ instead converged with SagS-dependent regulation at the level of BrlR. This was supported by multicopy expression of <i>sagS</i> failing to restore biofilm antibiotic tolerance by <i>ΔfleQ</i> to wild-type levels (and <i>vice versa</i>) and by biofilms formed by the <i>ΔfleQΔsagS</i> double mutant being as susceptible as <i>ΔfleQ</i> and <i>ΔsagS</i> biofilms. Increased antibiotic susceptibility was independent of BrlR abundance or BrlR DNA binding but coincided with significantly reduced transcript abundance of the BrlR-activated <i>mexCD-oprJ</i> and PA1874-77, encoding an ABC transporter previously shown to contribute to the tolerance of biofilms to tobramycin and norfloxacin. FleQ- dependent regulation of gene expression was indirect. Co-immunoprecipitation and BACTH assays indicated FleQ to interact with SagS via its HisKA-Rec domain, likely suggesting FleQ and SagS to likely work in concert to enable biofilm antibiotic tolerance<b>,</b> by finetuning the expression of BrlR activated genes.IMPORTANCEIn <i>P. aeruginosa</i>, FleQ inversely regulates the expression of genes encoding flagella and biofilm matrix components, including exopolysaccharide (Pel, Psl) in a manner dependent on the levels of c-di-GMP. Our findings expand on the role of FleQ from regulating the transition to the biofilm mode of growth to FleQ contributing to the antimicrobial tolerance phenotype of biofilms, by FleQ affecting the expression of PA1874-77, a downstream target of the SagS-dependent transcriptional regulator BrlR. Importantly, our findings suggest FleQ works in concert with SagS, likely via FleQ-SagS protein-protein interactions, to enable the formation of inherently tolerant <i>P. aeruginosa</i> biofilms.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0050324"},"PeriodicalIF":2.7,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12096822/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143991588","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":"<i>Bacillus subtilis</i> MurJ and Amj Lipid II flippases are not essential for growth.","authors":"Kiera Englehart, Jonathan Dworkin","doi":"10.1128/jb.00078-25","DOIUrl":"10.1128/jb.00078-25","url":null,"abstract":"<p><p>Identification of the protein that mediates transbilayer transport of the undecaprenyl-pyrophosphate (Und-PP) linked peptidoglycan precursor Lipid II has long been a subject of investigation. Candidates belonging to both the MOP (multidrug/oligosaccharidyl-lipid/polysaccharide) and SEDS (shape, elongation, division and sporulation) families of transmembrane proteins have been proposed, exhibiting characteristics consistent with mediating this process, including genetic essentiality and biochemical activity. While MOP family proteins including MurJ are widely considered to be the primary Lipid II transporter, questions still remain including a role for the SEDS proteins in this process. We and others previously showed that a <i>Bacillus subtilis</i> strain lacking all four MurJ homologs is viable, thereby implicating a separate mode of Lipid II transport across the membrane. However, a subsequent report of synthetic essentiality between <i>B. subtilis</i> MurJ and the flippase Amj suggested that they are necessary and sufficient. Here, we show that this effect is alleviated by excess synthesis of the enzyme responsible for Und-PP production. Thus, the inviability of a <i>murJ-amj</i> double mutant strain is not due to the essentiality of these enzymes for flipping Lipid II but is instead most likely a consequence of a reduction of free Und-PP levels. This result is consistent with a non-MOP-dependent pathway for Lipid II transport across the cytoplasmic membrane to enable cell wall peptidoglycan synthesis.IMPORTANCEThe assembly of peptidoglycan (PG), the typically essential polymer that provides structural integrity to bacterial cells, begins with the synthesis of the Lipid II monomer in the cytoplasm and along the cytoplasmic face of the inner membrane. Lipid II is then translocated across the membrane to the extracellular site of polymerization. The mechanistic basis for this process remains unclear, with genetic and/or biochemical evidence pointing to two different families of conserved membrane proteins. Here, we present genetic evidence that only one of these two families is essential in <i>Bacillus subtilis</i>.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0007825"},"PeriodicalIF":2.7,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12096821/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143779932","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":"Maltodextrin transport in the extremely thermophilic, lignocellulose degrading bacterium <i>Anaerocellum bescii</i> (f. <i>Caldicellulosiruptor bescii</i>).","authors":"Hansen Tjo, Virginia Jiang, Jerelle A Joseph, Jonathan M Conway","doi":"10.1128/jb.00401-24","DOIUrl":"10.1128/jb.00401-24","url":null,"abstract":"<p><p>Sugar transport into microbial cells is a critical, yet understudied step in the conversion of lignocellulosic biomass to metabolic products. <i>Anaerocellum bescii</i> (formerly <i>Caldicellulosiruptor bescii</i>) is an extremely thermophilic, anaerobic bacterium that readily degrades the cellulose and hemicellulose components of lignocellulosic biomass into a diversity of oligosaccharide substrates. Despite significant understanding of how this microorganism degrades lignocellulose, the mechanisms underlying its highly efficient transport of the released oligosaccharides into the cell are comparatively underexplored. Here, we identify and characterize the ATP-binding cassette (ABC) transporters in <i>A. bescii</i> governing maltodextrin transport. Utilizing past transcriptomic studies on <i>Anaerocellum</i> and <i>Caldicellulosiruptor</i> species, we identify two maltodextrin transporters in <i>A. bescii</i> and express and purify their substrate-binding proteins (Athe_2310 and Athe_2574) for characterization. Using differential scanning calorimetry and isothermal titration calorimetry, we show that Athe_2310 strongly interacts with shorter maltodextrins, such as maltose and trehalose, with dissociation constants in the micromolar range, while Athe_2574 binds longer maltodextrins, with dissociation constants in the sub-micromolar range. Using a sequence-structure-function comparison approach combined with molecular modeling, we provide context for the specificity of each of these substrate-binding proteins. We propose that <i>A. bescii</i> utilizes orthogonal ABC transporters to uptake malto-oligosaccharides of different lengths to maximize transport efficiency.</p><p><strong>Importance: </strong>Here, we reveal the biophysical and structural basis for oligosaccharide transport by two maltodextrin ATP-binding cassette (ABC) transporters in <i>Anaerocellum bescii</i>. This is the first biophysical characterization of carbohydrate uptake in this organism and establishes a workflow for characterizing other oligosaccharide transporters in <i>A. bescii</i> and similar biomass-degrading thermophiles of interest for lignocellulosic bioprocessing. By deciphering the mechanisms underlying high-affinity sugar uptake in <i>A. bescii</i>, we shed light on an underexplored step between extracellular lignocellulose degradation and intracellular conversion of sugars to metabolic products. This understanding will expand opportunities for harnessing sugar transport in thermophiles to reshape lignocellulose bioprocessing as part of a renewable bioeconomy.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0040124"},"PeriodicalIF":2.7,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12096829/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143991614","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":"Azithromycin represses evolution of ceftazidime/avibactam resistance by translational repression of <i>rpoS</i> in <i>Pseudomonas aeruginosa</i>.","authors":"Congjuan Xu, Jie Feng, Yuchen Zhou, Huan Ren, Xiaolei Pan, Shuiping Chen, Xuehua Liu, Guanxian Li, Jinjin Li, Bin Geng, Linlin Gao, Zhihui Cheng, Yongxin Jin, Un-Hwan Ha, Shouguang Jin, Iain L Lamont, Daniel Pletzer, Weihui Wu","doi":"10.1128/jb.00552-24","DOIUrl":"10.1128/jb.00552-24","url":null,"abstract":"<p><p>Antibiotic combinations can slow down resistance development and/or achieve synergistic therapeutic effects. In this study, we observed that a combined use of ceftazidime-avibactam (CZA) with azithromycin effectively repressed CZA resistance development in <i>Pseudomonas aeruginosa</i>. Transcriptome analysis revealed that subinhibitory concentrations of azithromycin reduced the expression of genes involved in stress-induced mutagenesis, including the stress response sigma factor <i>rpoS</i>. Interestingly, ribosome profiling revealed global redistribution of ribosomes by azithromycin, among which ribosome stalling was significantly intensified near the 5´ terminus of the <i>rpoS</i> mRNA. Further DNA mutational analysis revealed that azithromycin represses the translation of <i>rpoS</i> through its 5´-terminal rare codons, which in turn reduced its transcription. These <i>in vitro</i> observations have been recapitulated <i>in vivo</i> where azithromycin-repressed CZA resistance development when <i>P. aeruginosa</i> was passaged in mice. Overall, our study revealed the molecular mechanism of azithromycin-mediated repression of antibiotic resistance development, providing a promising antibiotic combination for the treatment of <i>P. aeruginosa</i> infections.IMPORTANCEAntibiotic resistance, a global public health challenge, demands the development of novel antibiotics and therapeutic strategies. Ceftazidime-avibactam (CZA) is a combination of a β-lactam antibiotic with a β-lactamase inhibitor that is effective against various gram-negative bacteria such as <i>Pseudomonas aeruginosa</i>. However, clinical CZA-resistant isolates have been reported. Here, we found that combining CZA with azithromycin can effectively suppress the development of resistance in <i>P. aeruginosa in vitro</i> and <i>in vivo</i>. Moreover, we found that azithromycin represses the translation initiation of <i>rpoS</i> through its 5´-terminal rare and less frequent codons, thereby subsequently reducing the mutational frequency of CZA resistance. Therefore, our work provides a promising antibiotic combination for the treatment of <i>P. aeruginosa</i> infections.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0055224"},"PeriodicalIF":2.7,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12096824/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143992330","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 role of AdhE mutations in <i>Thermoanaerobacterium saccharolyticum</i>.","authors":"João Henrique T M Fabri, Angel Pech-Canul, Samantha J Ziegler, Tucker Emme Burgin, Isaiah D Richardson, Marybeth I Maloney, Yannick J Bomble, Lee R Lynd, Daniel G Olson","doi":"10.1128/jb.00015-25","DOIUrl":"10.1128/jb.00015-25","url":null,"abstract":"<p><p><i>Thermoanaerobacterium saccharolyticum</i> is a thermophilic anaerobic bacterium that natively ferments a variety of hemicellulose substrates to organic acids and alcohols. It has recently been engineered to produce ethanol at high yield and titer; however, it uses a unique metabolic pathway for ethanol production that is poorly characterized. One of the distinctive aspects of this pathway is the presence of acetyl-CoA as an intermediate metabolite. In this organism, acetyl-CoA is converted to ethanol by a bifunctional AdhE enzyme. This enzyme has been a frequent target for mutations, and in many cases, the function of these mutations was unknown. Using a combination of genetic modifications, enzyme assays, and computational analysis, we have developed a better understanding of how mutations in AdhE affect ethanol production in the engineered homoethanologen strain. We identify a set of approximately interchangeable AdhE mutations (G544D, T597K, T597I, and T605I), whose function is to disrupt the activity of the alcohol dehydrogenase (ADH) domain of AdhE. This reduces NADH-linked ADH activity, which dramatically increases ethanol tolerance and changes the overall stoichiometry of acetaldehyde to ethanol conversion. Furthermore, our improved understanding of the function of these AdhE mutations calls into question a proposed feature of AdhE enzymes known as substrate channeling-direct transfer of acetaldehyde between the two domains of the AdhE enzyme. This improved the understanding of the role of AdhE mutations in <i>T. saccharolyticum</i> and provides deeper insights into the function of the unique ethanol production pathway in this organism.</p><p><strong>Importance: </strong>Many anaerobic bacteria maintain redox equilibrium by producing reduced organic compounds such as ethanol. The final two steps of ethanol production are mediated by a bifunctional enzyme, AdhE, and this enzyme is a frequent target of mutations in strains engineered for increased ethanol production. Paradoxically, these mutations increase ethanol production by eliminating the activity of one domain of the AdhE enzyme (the ADH domain). This provides additional support for a redox-imbalance theory of alcohol tolerance, which challenges the prevailing hypothesis that alcohol tolerance is associated with cell membrane effects.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0001525"},"PeriodicalIF":2.7,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12096837/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144019560","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":"Genome-wide characterization of hypothiocyanite stress response in <i>Escherichia coli</i>.","authors":"Julia D Meredith, Michael J Gray","doi":"10.1128/jb.00524-24","DOIUrl":"10.1128/jb.00524-24","url":null,"abstract":"<p><p>Oxidative stress is one of the major methods of microbial population control and pathogen clearing by the mammalian immune system. The methods by which bacteria are able to escape damage by host-derived oxidants such as hydrogen peroxide (H₂O₂) and hypochlorous acid (HOCl) have been relatively well described, while other oxidants' effects on bacteria and their genetic responses are not as well understood. Hypothiocyanite/hypothiocyanous acid (OSCN^-/HOSCN) is one such oxidative stress agent. In this study, we used RNA-sequencing to characterize the global transcriptional response of <i>Escherichia coli</i> to treatment with HOSCN and the impact of deletions of the HOSCN resistance proteins RclA (HOSCN reductase), RclB, and RclC on that response. The HOSCN response of <i>E. coli</i> was different from the previously characterized responses of <i>E. coli</i> to other oxidants such as H₂O₂, superoxide, or HOCl and distinct from the reported responses of other bacteria such as <i>Streptococcus pneumoniae</i> and <i>Pseudomonas aeruginosa</i> to HOSCN. Strikingly, deletion of any one of the Rcl proteins had very similar effects on the transcriptional response to HOSCN, indicating that any disruption of HOSCN defense in <i>E. coli</i> results in similar impacts, despite the fact that we do not currently understand the mechanism(s) by which RclB and RclC contribute to that defense.</p><p><strong>Importance: </strong>Understanding how bacteria sense and respond to oxidative stress provides insights into how our bodies interact with the microbial population within us. In this study, we have characterized the genetic response of <i>E. coli</i> to the important immune oxidant hypothiocyanite and investigated the role of <i>rclABC</i> genes in that response.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0052424"},"PeriodicalIF":2.7,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12096828/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143982064","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":"<i>Mycobacterium marinum</i> as a model for understanding principles of mycobacterial pathogenesis.","authors":"Aruna R Menon, Rebecca J Prest, David M Tobin, Patricia A Champion","doi":"10.1128/jb.00047-25","DOIUrl":"10.1128/jb.00047-25","url":null,"abstract":"<p><p><i>Mycobacterium marinum</i> is a fish pathogen that has become a powerful and well-established model that has accelerated our understanding of the mechanisms of mycobacterial disease. <i>M. marinum</i> is a versatile surrogate for understanding the closely related human pathogen <i>M. tuberculosis</i>, which causes tuberculosis in humans. <i>M. marinum</i> has defined key mechanisms of pathogenesis, both shared with <i>M. tuberculosis</i> and unique to this species. In this review, we discuss the discovery of <i>M. marinum</i> as an occasional human pathogen, the shared aspects of pathogenesis with <i>M. tuberculosis,</i> and how <i>M. marinum</i> has been exploited as a model to define the molecular mechanisms of mycobacterial pathogenesis across several phases of infection.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0004725"},"PeriodicalIF":2.7,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12096832/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144002295","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}