Journal of Bacteriology最新文献

{"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":"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}

{"title":"MoaB2, a newly identified transcription factor, binds to σ^A in <i>Mycobacterium smegmatis</i>.","authors":"Barbora Brezovská, Subhash Narasimhan, Michaela Šiková, Hana Šanderová, Tomáš Kovaľ, Nabajyoti Borah, Mahmoud Shoman, Debora Pospíšilová, Viola Vaňková Hausnerová, Dávid Tužinčin, Martin Černý, Jan Komárek, Martina Janoušková, Milada Kambová, Petr Halada, Alena Křenková, Martin Hubálek, Mária Trundová, Jan Dohnálek, Jarmila Hnilicová, Lukáš Žídek, Libor Krásný","doi":"10.1128/jb.00066-24","DOIUrl":"10.1128/jb.00066-24","url":null,"abstract":"<p><p>In mycobacteria, σ^A is the primary sigma factor. This essential protein binds to RNA polymerase (RNAP) and mediates transcription initiation of housekeeping genes. Our knowledge about this factor in mycobacteria is limited. Here, we performed an unbiased search for interacting partners of <i>Mycobacterium smegmatis</i> σ^A. The search revealed a number of proteins; prominent among them was MoaB2. The σ^A-MoaB2 interaction was validated and characterized by several approaches, revealing that it likely does not require RNAP and is specific, as alternative σ factors (<i>e.g.</i>, closely related σ^B) do not interact with MoaB2. The structure of MoaB2 was solved by X-ray crystallography. By immunoprecipitation and nuclear magnetic resonance, the unique, unstructured N-terminal domain of σ^A was identified to play a role in the σ^A-MoaB2 interaction. Functional experiments then showed that MoaB2 inhibits σ^A-dependent (but not σ^B-dependent) transcription and may increase the stability of σ^A in the cell. We propose that MoaB2, by sequestering σ^A, has a potential to modulate gene expression. In summary, this study has uncovered a new binding partner of mycobacterial σ^A, paving the way for future investigation of this phenomenon.IMPORTANCEMycobacteria cause serious human diseases such as tuberculosis and leprosy. The mycobacterial transcription machinery is unique, containing transcription factors such as RbpA, CarD, and the RNA polymerase (RNAP) core-interacting small RNA Ms1. Here, we extend our knowledge of the mycobacterial transcription apparatus by identifying MoaB2 as an interacting partner of σ^A, the primary sigma factor, and characterize its effects on transcription and σ^A stability. This information expands our knowledge of interacting partners of subunits of mycobacterial RNAP, providing opportunities for future development of antimycobacterial compounds.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0006624"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11656743/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142583303","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":"Quorum sensing regulation of Psl polysaccharide production by <i>Pseudomonas aeruginosa</i>.","authors":"Jeffrey N Carey, Sabrina Lamont, Daniel J Wozniak, Ajai A Dandekar, Matthew R Parsek","doi":"10.1128/jb.00312-24","DOIUrl":"10.1128/jb.00312-24","url":null,"abstract":"<p><p><i>Pseudomonas aeruginosa</i> is a common opportunistic pathogen and a model organism for studying bacterial sociality. A social behavior of <i>P. aeruginosa</i> that is critical for its success as a pathogen is its ability to form protective biofilms. Many of <i>P. aeruginosa</i>'s social phenotypes are regulated by quorum sensing-a type of cell-cell communication that allows bacteria to respond to population density. Although biofilm formation is known to be affected by quorum sensing, evidence for direct regulation of biofilm production by quorum regulators has remained elusive. In this work, we show that production of the major biofilm matrix polysaccharide Psl in <i>P. aeruginosa</i> PAO1 is regulated by the quorum regulators LasR and RhlR in stationary-phase cultures. Secretion of Psl into the culture medium requires LasR, RhlR, and the quorum signal molecules <i>N</i>-3-oxo-dodecanoyl-homoserine lactone and <i>N</i>-butanoyl homoserine lactone. Psl production in strains unable to synthesize the homoserine lactone signals can be restored by exogenous introduction of the signal molecules. We found that LasR and RhlR perform different roles in the regulation of Psl production: LasR acts at the promoter of the <i>psl</i> operon and activates transcription of the Psl biosynthetic genes, while RhlR activates translation of the <i>psl</i> transcripts. This work contributes to our understanding of the overlapping but distinct functions of the Las and Rhl quorum-sensing systems and implicates both in the direct regulation of biofilm matrix production.IMPORTANCE<i>Pseudomonas aeruginosa</i> biofilms are responsible for many treatment-resistant infections in humans. Many cooperative behaviors in <i>P. aeruginosa</i> are controlled by quorum sensing, but evidence for a direct role of quorum sensing in the regulation of biofilm matrix production has been scant. In this work, we show that the Las and Rhl quorum-sensing systems have distinct roles in regulating production of the matrix polysaccharide Psl and that this regulation happens at the level of transcription (Las) and translation (Rhl) of the <i>psl</i> operon. These findings deepen our understanding of overlapping functions of Las and Rhl quorum sensing and the complex regulation of biofilm development in <i>P. aeruginosa</i>.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0031224"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11656772/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142621091","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":"Architectural dissection of adhesive bacterial cell surface appendages from a \"molecular machines\" viewpoint.","authors":"Olivia E R Smith, Tanmay A M Bharat","doi":"10.1128/jb.00290-24","DOIUrl":"10.1128/jb.00290-24","url":null,"abstract":"<p><p>The ability of bacteria to interact with and respond to their environment is crucial to their lifestyle and survival. Bacterial cells routinely need to engage with extracellular target molecules, in locations spatially separated from their cell surface. Engagement with distant targets allows bacteria to adhere to abiotic surfaces and host cells, sense harmful or friendly molecules in their vicinity, as well as establish symbiotic interactions with neighboring cells in multicellular communities such as biofilms. Binding to extracellular molecules also facilitates transmission of information back to the originating cell, allowing the cell to respond appropriately to external stimuli, which is critical throughout the bacterial life cycle. This requirement of bacteria to bind to spatially separated targets is fulfilled by a myriad of specialized cell surface molecules, which often have an extended, filamentous arrangement. In this review, we compare and contrast such molecules from diverse bacteria, which fulfil a range of binding functions critical for the cell. Our comparison shows that even though these extended molecules have vastly different sequence, biochemical and functional characteristics, they share common architectural principles that underpin bacterial adhesion in a variety of contexts. In this light, we can consider different bacterial adhesins under one umbrella, specifically from the point of view of a modular molecular machine, with each part fulfilling a distinct architectural role. Such a treatise provides an opportunity to discover fundamental molecular principles governing surface sensing, bacterial adhesion, and biofilm formation.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0029024"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7616799/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142583301","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":"Increasing prevalence of bacteriocin carriage in a 6-year hospital cohort of <i>E. faecium</i>.","authors":"Andrea Garretto, Suzanne Dawid, Robert Woods","doi":"10.1128/jb.00294-24","DOIUrl":"10.1128/jb.00294-24","url":null,"abstract":"<p><p>Vancomycin-resistant enterococci (VRE) are important pathogens in hospitalized patients; however, the factors involved in VRE colonization of hospitalized patients are not well characterized. Bacteriocins provide a competitive advantage to enterococci in experimental models of colonization, but little is known about bacteriocin content in samples derived from humans and even less is known about their dynamics in the clinical setting. To identify bacteriocins which may be relevant in the transmission of VRE, we present a systematic analysis of bacteriocin content in the genomes of 2,248 patient-derived <i>E. faecium</i> isolates collected over a 6-year period from a single hospital system. We used computational methods to broadly search for bacteriocin structural genes and a functional assay to look for phenotypes consistent with bacteriocin expression. We identified homology to 15 different bacteriocins, with 2 having a high presence in this clinical cohort. Bacteriocin 43 (bac43) was found in a total of 58% of isolates, increasing from 8% to 91% presence over the 6-year collection period. There was little genetic variation in the bac43 structural or immunity genes across isolates. The enterocin A structural gene was found in 98% of isolates, but only 0.3% of isolates had an intact enterocin A gene cluster and displayed a bacteriocin-producing phenotype. This study presents a wide survey of bacteriocins from hospital isolates and identified bac43 as highly conserved, increasing in prevalence, and phenotypically functional. This makes bac43 an interesting target for future investigation for a potential role in <i>E. faecium</i> transmission.IMPORTANCEWhile enterococci are a normal inhabitant of the human gut, vancomycin-resistant <i>E. faecalis</i> and <i>E. faecium</i> are urgent public health threats responsible for hospital-associated infections. Bacteriocins are ribosomally synthesized antimicrobial proteins and are commonly used by bacteria to provide a competitive advantage in polymicrobial environments. Bacteriocins have the potential to be used by <i>E. faecium</i> to invade and dominate the human gut leading to a greater propensity for transmission. In this work, we explore bacteriocin content in a defined clinically derived population of <i>E. faecium</i> using both genetic and phenotypic studies. We show that one highly active bacteriocin is increasing in prevalence over time and demonstrates great potential relevance to <i>E. faecium</i> transmission.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0029424"},"PeriodicalIF":2.7,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11656788/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142780289","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 vibriophage-encoded inhibitor OrbA abrogates BREX-mediated defense through the ATPase BrxC.","authors":"Reid T Oshiro, Drew T Dunham, Kimberley D Seed","doi":"10.1128/jb.00206-24","DOIUrl":"10.1128/jb.00206-24","url":null,"abstract":"<p><p>Bacteria and phages are locked in a co-evolutionary arms race where each entity evolves mechanisms to restrict the proliferation of the other. Phage-encoded defense inhibitors have proven powerful tools to interrogate how defense systems function. A relatively common defense system is BREX (bacteriophage exclusion); however, how BREX functions to restrict phage infection remains poorly understood. A BREX system encoded by the <u>s</u>ulfametho<u>x</u>azole and <u>t</u>rimethoprim (SXT) integrative and conjugative element, <i>Vch</i>Ind5, was recently identified in <i>Vibrio cholerae</i>, the causative agent of the diarrheal disease cholera. The lytic phage ICP1 (<u>I</u>nternational Centre for Diarrhoeal Disease Research, Bangladesh <u>c</u>holera <u>p</u>hage <u>1</u>) that co-circulates with <i>V. cholerae</i> encodes the BREX-inhibitor OrbA, but how OrbA inhibits BREX is unclear. Here, we determine that OrbA inhibits BREX using a unique mechanism from known BREX inhibitors by directly binding to the BREX component BrxC. BrxC has a functional ATPase domain that, when mutated, not only disrupts BrxC function but also alters how BrxC multimerizes. Furthermore, we find that OrbA binding disrupts BrxC-BrxC interactions. We determine that OrbA cannot bind BrxC encoded by the distantly related BREX system encoded by the aSXT <i>Vch</i>Ban9, and thus fails to inhibit this BREX system that also circulates in epidemic <i>V. cholerae</i>. Lastly, we find that homologs of the <i>Vch</i>Ind5 BrxC are more diverse than the homologs of the <i>Vch</i>Ban9 BrxC. These data provide new insight into the function of the BrxC ATPase and highlight how phage-encoded inhibitors can disrupt phage defense systems using different mechanisms.IMPORTANCEWith renewed interest in phage therapy to combat antibiotic-resistant pathogens, understanding the mechanisms bacteria use to defend themselves against phages and the counter-strategies phages evolve to inhibit defenses is paramount. Bacteriophage exclusion (BREX) is a common defense system with few known inhibitors. Here, we probe how the vibriophage-encoded inhibitor OrbA inhibits the BREX system of <i>Vibrio cholerae</i>, the causative agent of the diarrheal disease cholera. By interrogating OrbA function, we have begun to understand the importance and function of a BREX component. Our results demonstrate the importance of identifying inhibitors against defense systems, as they are powerful tools for dissecting defense activity and can inform strategies to increase the efficacy of some phage therapies.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0020624"},"PeriodicalIF":2.7,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11580459/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142466183","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>Vibrio cholerae</i>: a fundamental model system for bacterial genetics and pathogenesis research.","authors":"Julia C van Kessel, Andrew Camilli","doi":"10.1128/jb.00248-24","DOIUrl":"10.1128/jb.00248-24","url":null,"abstract":"<p><p>Species of the <i>Vibrio</i> genus occupy diverse aquatic environments ranging from brackish water to warm equatorial seas to salty coastal regions. More than 80 species of <i>Vibrio</i> have been identified, many of them as pathogens of marine organisms, including fish, shellfish, and corals, causing disease and wreaking havoc on aquacultures and coral reefs. Moreover, many <i>Vibrio</i> species associate with and thrive on chitinous organisms abundant in the ocean. Among the many diverse <i>Vibrio</i> species, the most well-known and studied is <i>Vibrio cholerae</i>, discovered in the 19th century to cause cholera in humans when ingested. The <i>V. cholerae</i> field blossomed in the late 20th century, with studies broadly examining <i>V. cholerae</i> evolution as a human pathogen, natural competence, biofilm formation, and virulence mechanisms, including toxin biology and virulence gene regulation. This review discusses some of the historic discoveries of <i>V. cholerae</i> biology and ecology as one of the fundamental model systems of bacterial genetics and pathogenesis.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0024824"},"PeriodicalIF":2.7,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11580405/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142466177","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}