Journal of Bacteriology最新文献

{"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":"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":"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":"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}

{"title":"Identification and characterization of the <i>Bacillus subtilis</i> spore germination protein GerY.","authors":"Fernando H Ramírez-Guadiana, Anna P Brogan, David Z Rudner","doi":"10.1128/jb.00399-24","DOIUrl":"10.1128/jb.00399-24","url":null,"abstract":"<p><p>In response to starvation, endospore-forming bacteria differentiate into stress-resistant spores that can remain dormant for years yet rapidly germinate and resume growth when nutrients become available. To identify uncharacterized factors involved in the exit from dormancy, we performed a transposon-sequencing screen taking advantage of the loss of spore heat resistance that accompanies germination. We reasoned that transposon insertions that impair but do not block germination will lose resistance more slowly than wild type after exposure to nutrients and will therefore survive heat treatment. Using this approach, we identified most of the known germination genes and several new ones. We report an initial characterization of 15 of these genes and a more detailed analysis of one (<i>ymaF</i>). Spores lacking <i>ymaF</i> (renamed <i>gerY</i>) are impaired in germination in response to both L-alanine and L-asparagine, D-glucose, D-fructose, and K⁺. GerY is a soluble protein synthesized under <i>σ</i>^<i>E</i> control in the mother cell. A YFP-GerY fusion localizes around the developing and mature spore in a manner that depends on CotE and SafA, indicating that it is a component of the spore coat. Coat proteins encoded by the <i>gerP</i> operon and <i>gerT</i> are also required for efficient germination, and we show that spores lacking two or all three of these loci have more severe defects in the exit from dormancy. Our data are consistent with a model in which GerY, GerT, and the GerP proteins are required for efficient transit of nutrients through the coat to access the germination receptors, but each acts independently in this process.</p><p><strong>Importance: </strong>Pathogens in the orders Bacillales and Clostridiales resist sterilization by differentiating into stress-resistant spores. Spores are metabolically inactive and can remain dormant for decades, yet upon exposure to nutrients, they rapidly resume growth, causing food spoilage, food-borne illness, or life-threatening disease. The exit from dormancy, called germination, is a key target in combating these important pathogens. Here, we report a high-throughput genetic screen using transposon sequencing to identify novel germination factors that ensure the efficient exit from dormancy. We identify several new factors and characterize one in greater detail. This factor, renamed GerY, is part of the proteinaceous coat that encapsulates the dormant spore. Our data suggest that GerY enables efficient transit of nutrients through the coat to trigger germination.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0039924"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11656775/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142621089","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>Legionella pneumophila</i>, a Rosetta stone to understanding bacterial pathogenesis.","authors":"Katerina A Romanov, Tamara J O'Connor","doi":"10.1128/jb.00324-24","DOIUrl":"10.1128/jb.00324-24","url":null,"abstract":"<p><p><i>Legionella pneumophila</i> is an environmentally acquired pathogen that causes respiratory disease in humans. While the discovery of <i>L. pneumophila</i> is relatively recent compared to other bacterial pathogens, over the past 50 years, <i>L. pneumophila</i> has emerged as a powerhouse for studying host-pathogen interactions. In its natural habitat of fresh water, <i>L. pneumophila</i> interacts with a diverse array of protozoan hosts and readily evolve to expand their host range. This has led to the accumulation of the most extensive arsenal of secreted virulence factors described for a bacterial pathogen and their ability to infect humans. Within amoebae and human alveolar macrophages, the bacteria replicate within specialized membrane-bound compartments, establishing <i>L. pneumophila</i> as a model for studying intracellular vacuolar pathogens. In contrast, the virulence factors required for intracellular replication are specifically tailored to individual host cells types, allowing the pathogen to adapt to variation between disparate niches. The broad host range of this pathogen, combined with the extensive diversity and genome plasticity across the <i>Legionella</i> genus, has thus established this bacterium as an archetype to interrogate pathogen evolution, functional genomics, and ecology. In this review, we highlight the features of <i>Legionella</i> that establish them as a versatile model organism, new paradigms in bacteriology and bacterial pathogenesis resulting from the study of <i>Legionella</i>, as well as current and future questions that will undoubtedly expand our understanding of the complex and intricate biology of the microbial world.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0032424"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11656745/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142785699","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}