Journal of Bacteriology最新文献

{"title":"Exploring aggregation genes in a <i>P. aeruginosa</i> chronic infection model.","authors":"Alexa D Gannon, Jenet Matlack, Sophie E Darch","doi":"10.1128/jb.00429-24","DOIUrl":"10.1128/jb.00429-24","url":null,"abstract":"<p><p>Bacterial aggregates are observed in both natural and artificial environments. In the context of disease, aggregates have been isolated from chronic and acute infections. <i>Pseudomonas aeruginosa</i> (<i>Pa</i>) aggregates contribute significantly to chronic infections, particularly in the lungs of people with cystic fibrosis (CF). Unlike the large biofilm structures observed <i>in vitro</i>, <i>Pa</i> in CF sputum forms smaller aggregates (~10-1,000 cells), and the mechanisms behind their formation remain underexplored. This study aims to identify genes essential and unique <i>to</i> Pa aggregate formation in a synthetic CF sputum media (SCFM2). We cultured <i>Pa</i> strain PAO1 in SCFM2 and LB, both with and without mucin, and used RNA sequencing (RNA-seq) to identify differentially expressed genes. The presence of mucin revealed 13 significantly differentially expressed (DE) genes, predominantly downregulated, with 40% encoding hypothetical proteins unique to aggregates. Using high-resolution microscopy, we assessed the ability of mutants to form aggregates. Notably, no mutant exhibited a completely planktonic phenotype. Instead, we identified multiple spatial phenotypes described as \"normal,\" \"entropic,\" or \"impaired.\" Entropic mutants displayed tightly packed, raft-like structures, while impaired mutants had loosely packed cells. Predictive modeling linked the prioritized genes to metabolic shifts, iron acquisition, surface modification, and quorum sensing. Co-culture experiments with wild-type PAO1 revealed further spatial heterogeneity and the ability to \"rescue\" some mutant phenotypes, suggesting cooperative interactions during growth. This study enhances our understanding of <i>Pa</i> aggregate biology, specifically the genes and pathways unique to aggregation in CF-like environments. Importantly, it provides insights for developing therapeutic strategies targeting aggregate-specific pathways.</p><p><strong>Importance: </strong>This study identifies genes essential for the formation of <i>Pseudomonas aeruginosa</i> (Pa) aggregates in cystic fibrosis (CF) sputum, filling a critical gap in understanding their specific biology. Using a synthetic CF sputum model (SCFM2) and RNA sequencing, 13 key genes were identified, whose disruption led to distinct spatial phenotypes observed through high-resolution microscopy. The addition of wild-type cells either rescued the mutant phenotype or increased spatial heterogeneity, suggesting cooperative interactions are involved in aggregate formation. This research advances our knowledge of <i>Pa</i> aggregate biology, particularly the unique genes and pathways involved in CF-like environments, offering valuable insights for developing targeted therapeutic strategies against aggregate-specific pathways.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0042924"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784459/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807023","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":"An unusual activity of mycobacterial MutT1 Nudix hydrolase domain as a protein phosphatase regulates nucleoside diphosphate kinase function.","authors":"Elhassan Ali Fathi Emam, Koyel Roy, Devendra Pratap Singh, Deepak K Saini, Umesh Varshney","doi":"10.1128/jb.00314-24","DOIUrl":"10.1128/jb.00314-24","url":null,"abstract":"<p><p>MutT proteins are Nudix hydrolases characterized by the presence of a Nudix box, GX5EX7REUXEEXGU, where U is a bulky hydrophobic residue and X is any residue. Major MutT proteins hydrolyze 8-oxo-(d)GTP (8-oxo-GTP or 8-oxo-dGTP) to the corresponding 8-oxo-(d)GMP, preventing their incorporation into nucleic acids. Mycobacterial MutT1 comprises an N-terminal domain (NTD) harboring the Nudix box motif, and a C-terminal domain (CTD) harboring the RHG histidine phosphatase motif. Interestingly, unlike other MutTs, the MutT1 hydrolyses the mutagenic 8-oxo-(d)GTP to the corresponding 8-oxo-(d)GDP. Nucleoside diphosphate kinase (NDK), a conserved protein, carries out reversible conversion of (d)NDPs to (d)NTPs through phospho-NDK (NDK-<i>Pi</i>) intermediate. Recently, we showed that NDK-<i>Pi</i> converts 8-oxo-dGDP to 8-oxo-dGTP and escalates A to C mutations in a MutT-deficient <i>Escherichia coli</i>. We now show that both <i>Mycobacterium tuberculosis</i> MutT1 and <i>Mycobacterium smegmatis</i> MutT1, through their NTD (Nudix hydrolase motifs) function as protein phosphatase to regulate the levels of NDK-<i>Pi</i> and prevent it from catalyzing conversion of (d)NDPs to (d)NTPs (including conversion of 8-oxo-dGDP to 8-oxo-dGTP). To corroborate this function, we show that <i>Msm</i>MutT1 decreases A to C mutations in <i>E. coli</i> under the conditions of <i>Eco</i>NDK overexpression.IMPORTANCEMutT proteins, having a Nudix box domain, hydrolyze the mutagenic 8-oxo-dGTP to 8-oxo-dGMP. However, mycobacterial MutT (MutT1) comprises an N-terminal domain (NTD) harboring a Nudix box, and a C-terminal domain (CTD) harboring an RHG histidine phosphatase. Unlike other MutTs, mycobacterial MutT1 hydrolyses 8-oxo-dGTP to 8-oxo-dGDP. Nucleoside diphosphate kinase (NDK), a conserved protein, converts 8-oxo-dGDP to 8-oxo-dGTP through phospho-NDK (NDK-<i>Pi</i>) intermediate and escalates A to C mutations. Here, we show that the mycobacterial MutT1 is unprecedented in that its NTD (Nudix box), functions as protein phosphatase to regulate NDK-<i>Pi</i> levels and prevents it from converting dNDPs to dNTPs (including 8-oxo-dGDP to 8-oxo-dGTP conversion). In addition, mycobacterial MutT1 decreases A to C mutations in <i>Escherichia coli</i> under the conditions of NDK overexpression.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0031424"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784022/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807069","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":"SbcB facilitates natural transformation in <i>Vibrio cholerae</i> in an exonuclease-independent manner.","authors":"Triana N Dalia, Ankur B Dalia","doi":"10.1128/jb.00419-24","DOIUrl":"10.1128/jb.00419-24","url":null,"abstract":"<p><p>Natural transformation (NT) is a conserved mechanism of horizontal gene transfer in bacterial species. During this process, DNA is taken up into the cytoplasm where it can be integrated into the host genome by homologous recombination. We have previously shown that some cytoplasmic exonucleases inhibit NT by degrading ingested DNA prior to its successful recombination. However, one exonuclease, SbcB, counterintuitively promotes NT in <i>Vibrio cholerae</i>. Here, through a systematic analysis of the distinct steps of NT, we show that SbcB acts downstream of DNA uptake into the cytoplasm, but upstream of recombinational branch migration. Through mutational analysis, we show that SbcB promotes NT in a manner that does not rely on its exonuclease activity. Finally, we provide genetic evidence that SbcB directly interacts with the primary bacterial recombinase, RecA. Together, these data advance our molecular understanding of horizontal gene transfer in <i>V. cholerae</i> and reveal that SbcB promotes homologous recombination during NT in a manner that does not rely on its canonical exonuclease activity.</p><p><strong>Importance: </strong>Horizontal gene transfer by natural transformation contributes to the spread of antibiotic resistance and virulence factors in bacterial species. Here, we study how one protein, SbcB, helps facilitate this process in the facultative bacterial pathogen <i>Vibrio cholerae</i>. SbcB is a well-known for its exonuclease activity (i.e., the ability to degrade the ends of linear DNA). Through this study, we uncover that while SbcB is important for natural transformation, it does not facilitate this process using its exonuclease activity. Thus, this work helps further our understanding of the molecular events required for this conserved evolutionary process and uncovers a function for SbcB beyond its canonical exonuclease activity.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0041924"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784430/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142818018","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 BfmRS stress response protects <i>Acinetobacter baumannii</i> against defects in outer membrane lipoprotein biogenesis.","authors":"Julianna Marotta, Alan Zhao, Philip N Rather, Marcin Grabowicz","doi":"10.1128/jb.00332-24","DOIUrl":"10.1128/jb.00332-24","url":null,"abstract":"<p><p>The outer membrane (OM) of Gram-negative bacteria is the outermost layer of the cell and serves as permeability barrier against environmental toxins, including antibiotics. The OM is built by several pathways that transport and assemble lipids and proteins into the OM. Since the OM is an essential organelle for the cell, envelope stress responses (ESRs) continuously monitor its assembly to preserve viability if defects arise. While ESRs have been extensively characterized in <i>Escherichia coli</i>, they are generally narrowly conserved. Lipoprotein trafficking to the OM via the \"Lol\" pathway is a linchpin for all OM assembly pathways. In <i>E. coli</i>, defects in this essential process are sensed when the sensor OM lipoprotein NlpE activates the CpxAR two-component system. Distantly related <i>Acinetobacter baumannii</i> encodes an NlpE homolog but lacks any Cpx homolog; how OM lipoprotein stress might be sensed and mitigated in these bacteria is therefore unclear. Here, we used CRISPRi to transiently induce defects in OM lipoprotein synthesis (targeting <i>lgt</i> and <i>lnt</i>) or trafficking (targeting <i>lolA</i>) in <i>A. baumannii</i>. We defined the transcriptional response to blocks in OM lipoprotein biogenesis. After scrutinizing candidate ESRs, we identified the BfmRS two-component systems as specifically critical for preserving <i>A. baumannii</i> viability during stress in OM lipoprotein biogenesis. Surprisingly, <i>A. baumannii</i> NlpE played no role in combatting OM lipoprotein stress. Our study identifies an <i>A. baumannii</i> ESR for OM lipoprotein biogenesis defects that acts in a distinct mechanism, not involving the NlpE sensor lipoprotein.</p><p><strong>Importance: </strong>As the cell's surface, the outer membrane (OM) of bacteria, such as <i>Acinetobacter baumannii</i>, is continuously under assault from the environment or host. OM integrity is needed for cell survival, and envelope stress responses (ESRs) act to detect and repair any defects. ESRs are well-defined in <i>Escherichia coli</i> but are poorly conserved. We sought to identify an ESR for the essential process of OM lipoprotein biogenesis in <i>A. baumannii</i>. We found that the BfmRS two-component system performs this function and does so without relying on its NlpE sensor homolog, suggesting a novel mechanism of stress sensing is involved in <i>A. baumannii</i>. Our work identifies a key cellular role for BfmRS.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0033224"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784087/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807063","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":"2024 Jack Kenney Award for Outstanding Service.","authors":"George A O'Toole","doi":"10.1128/jb.00494-24","DOIUrl":"10.1128/jb.00494-24","url":null,"abstract":"","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":"207 1","pages":"e0049424"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784191/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143065836","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":"Lipid a remodeling modulates outer membrane vesicle biogenesis by <i>Porphyromonas gingivalis</i>.","authors":"Sarah R Alaei, Alisa J King, Karim Banani, Angel Reddy, Joshua Ortiz, Alexa L Knight, Jessica Haldeman, Thet Hnin Su, Hana Park, Stephen R Coats, Sumita Jain","doi":"10.1128/jb.00336-24","DOIUrl":"10.1128/jb.00336-24","url":null,"abstract":"<p><p>Outer membrane vesicles (OMVs) are small membrane enclosed sacs released from bacteria which serve as carriers of biomolecules that shape interactions with the surrounding environment. The periodontal pathogen, <i>Porphyromonas gingivalis</i>, is a prolific OMV producer. Here, we investigated how the structure of lipid A, a core outer membrane molecule, influences <i>P. gingivalis</i> OMV production, OMV-dependent TLR4 activation, and biofilm formation. We examined mutant strains of <i>P. gingivalis</i> 33277 deficient for enzymes that alter lipid A phosphorylation and acylation status. The lipid A C4'-phosphatase (<i>lpxF</i>)-deficient strain and strains bearing inactivating point mutations in the LpxF active site displayed markedly reduced OMV production relative to WT. In contrast, strains deficient for either the lipid A C1-phosphatase (<i>lpxE</i>) or the lipid A deacylase (PGN_1123; <i>lpxZ</i>) genes did not display alterations in OMV abundance compared to WT. These data indicate that lipid A C4'-phosphate removal is required for typical OMV formation. In addition, OMVs produced by <i>ΔlpxF</i> and <i>ΔlpxZ</i> strains, possessing only penta-acylated lipid A, stimulated robust TLR4 activation, whereas OMVs obtained from WT and <i>ΔlpxE</i> strains, containing predominantly tetra-acylated lipid A, did not. Hence, lipid A remodeling modulates the capacity of OMVs to engage host TLR4-dependent immunity. Finally, we demonstrate an inverse relationship between OMV abundance and biofilm density, with the <i>∆lpxF</i> mutants forming denser biofilms than either WT, <i>ΔlpxE</i>, or <i>ΔlpxZ</i> strains. Therefore, OMVs may also contribute to pathogenesis by regulating biofilm formation and dispersal.IMPORTANCE<i>Porphyromonas gingivalis</i> is a bacterium strongly associated with periodontitis. <i>P. gingivalis</i> exports lipids, proteins, and other biomolecules that contribute to the bacterium's ability to persist in inflammatory conditions encountered during disease. These biomolecules are exported through several mechanisms, including via outer membrane vesicles (OMVs). Despite their ubiquity, the mechanisms that drive outer membrane vesicle production vary among bacteria and are not fully understood. In this study, we report that C4' dephosphorylation of lipid A, a major outer membrane molecule, is required for robust outer membrane vesicle production and biological function in <i>P. gingivalis</i>. This finding adds to the growing body of evidence that lipid A structure is an important factor in outer membrane vesicle biogenesis in diverse bacterial species.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0033624"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784228/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142807055","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":"MtlD as a therapeutic target for intestinal and systemic bacterial infections.","authors":"Andrew Schwieters, Allysa L Cole, Emily Rego, Chengyu Gao, Razieh Kebriaei, Vicki H Wysocki, John S Gunn, Brian M M Ahmer","doi":"10.1128/jb.00480-24","DOIUrl":"10.1128/jb.00480-24","url":null,"abstract":"<p><p>The ability to treat infections is threatened by the rapid emergence of antibiotic resistance among pathogenic microbes. Therefore, new antimicrobials are needed. Here we evaluate mannitol-1-phosphate 5-dehydrogenase (MtlD) as a potential new drug target. In many bacteria, mannitol is transported into the cell and phosphorylated by MtlA, the EIICBA component of a phosphoenolpyruvate-dependent sugar phosphotransferase system. MtlD catalyzes the conversion of mannitol-1-phosphate (Mtl-1P) to fructose-6-phosphate, which enters the glycolytic pathway. Mutants lacking <i>mtlD</i> are sensitive to mannitol due to accumulation of Mtl-1P. Here, we constructed <i>mtlD</i> mutants in four different bacterial species (<i>Cronobacter sakazakii</i>, <i>Pseudomonas aeruginosa,</i> five serovars of <i>Salmonella enterica</i>, and three strains of <i>Escherichia coli</i>), confirming and quantifying their mannitol sensitivity. The quantification of mannitol sensitivity <i>in vitro</i> was complicated by an inoculum effect and a resumption of growth following mannitol intoxication. The rate of resumption at different mannitol concentrations and cell population densities is fairly constant and reveals what is likely an intoxication processing rate. Provision of mannitol in drinking water, or by intraperitoneal injection, dramatically attenuates infection of a <i>Salmonella enterica</i> serovar Typhimurium <i>mtlD</i> mutant in mouse models of both gastroenteritis and systemic infection. Using CC003/Unc mice, we find that a <i>mtlD</i> mutant of <i>Salmonella enterica</i> serovar Typhi is also attenuated by provision of mannitol in drinking water. Therefore, we postulate that MtlD could be a valuable new therapeutic target.</p><p><strong>Importance: </strong>The ability to treat infections is threatened by the rapid emergence of antibiotic resistance. Mannitol is a polyol used in human medicine and the food industry. During catabolism of mannitol, many bacteria transport mannitol across the inner membrane forming the toxic intermediate mannitol-1-phosphate (Mtl-1P). Mtl-1P must be processed by mannitol dehydrogenase (MtlD) or it accumulates intracellularly, causing growth attenuation. We test and confirm here that <i>mtlD</i> mutants of <i>Escherichia coli</i> (including UPEC, and EHEC), <i>Salmonella</i> (including serovars Typhi, and Paratyphi A, B, and C), <i>Cronobacter</i>, and <i>Pseudomonas</i> experience mannitol sensitivity <i>in vitro</i>. Furthermore, providing mannitol in drinking water can alleviate both gastrointestinal and systemic <i>Salmonella</i> infections in mice. This suggests that inhibition of MtlD could be a viable antimicrobial strategy.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0048024"},"PeriodicalIF":2.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11784389/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142894583","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":"Bacterial microcompartment utilization in the human commensal <i>Escherichia coli</i> Nissle 1917.","authors":"Chania Clare, Jack W Rutter, Alex J H Fedorec, Stefanie Frank, Chris P Barnes","doi":"10.1128/jb.00269-24","DOIUrl":"10.1128/jb.00269-24","url":null,"abstract":"<p><p>Bacterial microcompartments (BMCs) are self-assembled protein structures often utilized by bacteria as a modular metabolic unit, enabling the catalysis and utilization of less common carbon and nitrogen sources within a self-contained compartment. The <i>ethanolamine (EA) utilization (eut)</i> BMC has been widely demonstrated in enteropathogens, such as <i>Salmonella enterica</i>, and current research is exploring its activity in the commensal species that populate the human gut. <i>Escherichia coli</i> Nissle 1917 (EcN) is a strong colonizer and probiotic in gut microbial communities and has been used extensively for microbiome engineering. In this study, the utilization of ethanolamine as a sole carbon source and the formation of the <i>eut</i> BMC in EcN were demonstrated through growth assays and visualization with transmission electron microscopy. Subsequently, flux balance analysis was used to further investigate the metabolic activity of this pathway. It was found that not only is the utilization of the <i>eut</i> BMC for the degradation of EA as a carbon source in EcN comparable with that of <i>Salmonella enterica</i> but also that ammonium is released into solution as a byproduct in EcN but not in <i>S. enterica</i>. Control of EA-dependent growth was demonstrated using different concentrations of the operon inducer, vitamin B₁₂. We show that vitamin B₁₂-dependent EA utilization as the sole carbon source enables growth in EcN, and demonstrate the concurrent formation of the BMC shell and inducible control of the <i>eut</i> operon.</p><p><strong>Importance: </strong>The human gut is a complex environment of different bacterial species, nutrient sources, and changing conditions that are essential for human health. An imbalance can allow for the emergence of opportunistic pathogens. Bacterial microcompartments (BMCs) are utilized by bacteria to metabolize less common nutrients, conferring a growth advantage. Although widely studied in enteropathogens, there is limited research on BMC activity in commensal species. We demonstrate the formation of the eut BMC and utilization of ethanolamine as a carbon source in the human gut commensal <i>Escherichia coli</i> Nissle 1917 (EcN). Additionally, we found increased ammonium production when EcN utilized ethanolamine but did not see the same in <i>Salmonella enterica</i>, highlighting potential differences in how these species affect the wider microbial community.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0026924"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7617246/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142785710","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":"Building permits-control of type IV pilus assembly by PilB and its cofactors.","authors":"Nathan A Roberge, Lori L Burrows","doi":"10.1128/jb.00359-24","DOIUrl":"10.1128/jb.00359-24","url":null,"abstract":"<p><p>Many bacteria produce type IV pili (T4P), surfaced-exposed protein filaments that enable cells to interact with their environment and transition from planktonic to surface-adapted states. T4P are dynamic, undergoing rapid cycles of filament extension and retraction facilitated by a complex protein nanomachine powered by cytoplasmic motor ATPases. Dedicated assembly motors drive the extension of the pilus fiber into the extracellular space, but like any machine, this process is tightly organized. These motors are coordinated by various ligands and binding partners, which control or optimize their functional associations with T4P machinery before cells commit to the crucial first step of building a pilus. This review focuses on the molecular mechanisms that regulate T4P extension motor function. We discuss secondary messenger-dependent transcriptional or post-translational regulation acting both directly on the motor and through protein effectors. We also discuss the recent discoveries of naturally occurring extension inhibitors as well as alternative mechanisms of pilus assembly and motor-dependent signaling pathways. Given that T4P are important virulence factors for many bacterial pathogens, studying these motor regulatory systems will provide new insights into T4P-dependent physiology and efficient strategies to disable them.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0035924"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11656802/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142604092","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":"Intracellular ATP concentration is a key regulator of bacterial cell fate.","authors":"Bo Li, Xiao Chen, Jin-Yu Yang, Song Gao, Fan Bai","doi":"10.1128/jb.00208-24","DOIUrl":"10.1128/jb.00208-24","url":null,"abstract":"<p><p>ATP, most widely known as the primary energy source for numerous cellular processes, also exhibits the characteristics of a biological hydrotrope. The viable but nonculturable (VBNC) and persister states are two prevalent dormant phenotypes employed by bacteria to survive challenging environments, both of which are associated with low metabolic activity. Here, we investigate the intracellular ATP concentration of individual VBNC and persister cells using a sensitive ATP biosensor QUEEN-7μ and reveal that both types of cells possess a lower intracellular ATP concentration than culturable and sensitive cells, although there is a certain overlap in the intracellular ATP concentrations between antibiotic-sensitive cells and persisters. Moreover, we successfully separated VBNC cells from culturable cells using fluorescence-activated cell sorting based on the intracellular ATP concentration threshold of 12.5 µM. Using an enriched VBNC cell population, we confirm that the precipitation of proteins involved in key biological processes promotes VBNC cell formation. Notably, using green light-illuminated proteorhodopsin (PR), we demonstrate that VBNC cells can be effectively resuscitated by elevating their intracellular ATP concentration. These findings highlight the crucial role of intracellular ATP concentration in the regulation of bacterial cell fate and provide new insights into the formation of VBNC and persister cells.IMPORTANCEThe viable but nonculturable (VBNC) and persister states are two dormant phenotypes employed by bacteria to counter stressful conditions and play a crucial role in chronic and recurrent bacterial infections. However, the lack of precise detection methods poses significant threats to public health. Our study reveals lower intracellular ATP concentrations in these states and establishes an ATP threshold for distinguishing VBNC from culturable cells. Remarkably, we revive VBNC cells by elevating their intracellular ATP levels. This echoes recent eukaryotic studies where modulating metabolism impacts outcomes like osteoarthritis treatment and lifespan extension in <i>Caenorhabditis elegans</i>. Our findings underscore the crucial role of intracellular ATP levels in governing bacterial fate, emphasizing ATP manipulation as a potential strategy to steer bacterial behavior.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0020824"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11656805/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142621090","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}