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  1. Book ; Online: LuxR Solos are Becoming Major Players in Cell-Cell Communication in Bacteria

    Ahmer, Brian M.M. / Venturi, Vittorio

    2016  

    Abstract: The most common quorum sensing (QS) system in Gram-negative bacteria occurs via N-acyl homoserine lactone (AHLs) signals. An archetypical system consists of a LuxI-family protein synthesizing the AHL signal which binds at quorum concentrations to the ... ...

    Abstract The most common quorum sensing (QS) system in Gram-negative bacteria occurs via N-acyl homoserine lactone (AHLs) signals. An archetypical system consists of a LuxI-family protein synthesizing the AHL signal which binds at quorum concentrations to the cognate LuxR-family transcription factors which then control gene expression by binding to specific sequences in target gene promoters. QS LuxR-family proteins are approximately 250 amino acids long and made up of two domains; at the N-terminus there is an autoinducer-binding domain whereas the C-terminus contains a DNA-binding helix-turn-helix (HTH) domain. QS LuxRs display surprisingly low similarities (18-25%) even if they respond to structurally similar AHLs. 95% of LuxRs share 9 highly conserved amino acid residues; six of these are hydrophobic or aromatic and form the cavity of the AHL-binding domain and the remaining three are in the HTH domain.-

    With only very few exceptions, the luxI/R cognate genes of AHL QS systems are located adjacent to each other. The sequencing of many bacterial genomes has revealed that many proteobacteria also possess LuxRs that do not have a cognate LuxI protein associated with them. These LuxRs have been called orphans and more recently solos. LuxR solos are widespread in proteobacterial species that possess a canonical complete AHL QS system as well as in species that do not. In many cases more than one LuxR solo is present in a bacterial genome. Scientists are beginning to investigate these solos.-

    Are solos responding to AHL signals? If present in a bacterium which possesses a canonical AHL QS system are solos an integral part of the regulatory circuit? Are LuxR solos eavesdropping on AHLs produced by neighboring bacteria? Have they evolved to respond to different signals instead of AHLs, and are these signals endogenously produced or exogenously provided? Are they involved in interkingdom signaling by responding to eukaryotic signals? Recent studies have revealed that LuxR solos are involved in several mechanisms of cell-cell communication in bacteria implicating them in bacterial intraspecies and interspecies communication as well as in interkingdom signaling by responding to molecules produced by eukaryotes. LuxR solos are likely to become major players in signaling since they are widespread among proteobacterial genomes and because initial studies highlight their different roles in bacterial communication.-
    Keywords Science (General) ; Biology (General)
    Size 1 electronic resource (122 p.)
    Publisher Frontiers Media SA
    Document type Book ; Online
    Note English ; Open Access
    HBZ-ID HT020090637
    ISBN 9782889199174 ; 2889199177
    Database ZB MED Catalogue: Medicine, Health, Nutrition, Environment, Agriculture

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  2. Article: Gut microbiome carbon and sulfur metabolisms support

    Leleiwi, Ikaia / Kokkinias, Katherine / Kim, Yongseok / Baniasad, Maryam / Shaffer, Michael / Sabag-Daigle, Anice / Daly, Rebecca A / Flynn, Rory M / Wysocki, Vicki H / Ahmer, Brian M M / Borton, Mikayla A / Wrighton, Kelly C

    bioRxiv : the preprint server for biology

    2024  

    Abstract: Salmonella ... ...

    Abstract Salmonella enterica
    Language English
    Publishing date 2024-01-19
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2024.01.16.575907
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: Time resolved multi-omics reveals diverse metabolic strategies of

    Kokkinias, Katherine / Sabag-Daigle, Anice / Kim, Yongseok / Leleiwi, Ikaia / Shaffer, Michael / Kevorkian, Richard / Daly, Rebecca A / Wysocki, Vicki H / Borton, Mikayla A / Ahmer, Brian M M / Wrighton, Kelly C

    bioRxiv : the preprint server for biology

    2024  

    Abstract: With a rise in antibiotic resistance and chronic infection, the metabolic response of : Importance: Identifying novel therapeutic strategies ... ...

    Abstract With a rise in antibiotic resistance and chronic infection, the metabolic response of
    Importance: Identifying novel therapeutic strategies for
    Language English
    Publishing date 2024-02-04
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2024.02.03.578763
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Identification of Small-Molecule Inhibitors of the Salmonella FraB Deglycase Using a Live-Cell Assay.

    Sabag-Daigle, Anice / Boulanger, Erin F / Thirugnanasambantham, Pankajavalli / Law, Jamison D / Bogard, Alex J / Behrman, Edward J / Gopalan, Venkat / Ahmer, Brian M M

    Microbiology spectrum

    2023  , Page(s) e0460622

    Abstract: Nontyphoidal salmonellosis is one of the most significant foodborne diseases in the United States and globally. There are no vaccines available for human use to prevent this disease, and only broad-spectrum antibiotics are available to treat complicated ... ...

    Abstract Nontyphoidal salmonellosis is one of the most significant foodborne diseases in the United States and globally. There are no vaccines available for human use to prevent this disease, and only broad-spectrum antibiotics are available to treat complicated cases of the disease. However, antibiotic resistance is on the rise and new therapeutics are needed. We previously identified the Salmonella
    Language English
    Publishing date 2023-02-21
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2807133-5
    ISSN 2165-0497 ; 2165-0497
    ISSN (online) 2165-0497
    ISSN 2165-0497
    DOI 10.1128/spectrum.04606-22
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Heating Rate during Shell Egg Thermal Treatment Elicits Stress Responses and Alters Virulence of Salmonella enterica Serovar Enteritidis; Implications for Shell Egg Pasteurization.

    Xu, Yumin / Abdelhamid, Ahmed G / Sabag-Daigle, Anice / Ahmer, Brian M M / Yousef, Ahmed E

    Applied and environmental microbiology

    2022  Volume 88, Issue 20, Page(s) e0114022

    Abstract: Thermal pasteurization of shell eggs, at various time-temperature combinations, has been proposed previously and implemented industrially. This study was conducted to determine if shell egg heating rate, which varies with different pasteurization ... ...

    Abstract Thermal pasteurization of shell eggs, at various time-temperature combinations, has been proposed previously and implemented industrially. This study was conducted to determine if shell egg heating rate, which varies with different pasteurization implementations, alters the Salmonella enterica serovar Enteritidis response to different stresses or expression of virulence. Shell eggs, containing Salmonella Enteritidis in yolk, were subjected to a low (2.4°C/min) or a high (3.5°C/min) heating rate during treatments that mimicked the pasteurization temperature come-up stage. The low heating rate protected Salmonella from the following processes: (i) lethal heat at the holding stage, (ii) loss of viability during 8-h cooling after heating, and (iii) sequential antimicrobial ozone treatment. Transcriptional analysis using Salmonella reporter strains revealed that the heat stress response gene
    MeSH term(s) Animals ; Mice ; Salmonella enteritidis ; Pasteurization/methods ; Heating ; Virulence ; Hot Temperature ; Eggs ; Ozone/pharmacology ; Egg Shell/chemistry ; Colony Count, Microbial ; Food Microbiology
    Chemical Substances Ozone (66H7ZZK23N)
    Language English
    Publishing date 2022-10-05
    Publishing country United States
    Document type Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 223011-2
    ISSN 1098-5336 ; 0099-2240
    ISSN (online) 1098-5336
    ISSN 0099-2240
    DOI 10.1128/aem.01140-22
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: The Role of Egg Yolk in Modulating the Virulence of

    Xu, Yumin / Abdelhamid, Ahmed G / Sabag-Daigle, Anice / Sovic, Michael G / Ahmer, Brian M M / Yousef, Ahmed E

    Frontiers in cellular and infection microbiology

    2022  Volume 12, Page(s) 903979

    Abstract: Contribution of food vehicles to pathogenicity of disease-causing microorganisms is an important but overlooked research field. The current study was initiated to reveal the relationship between virulence ... ...

    Abstract Contribution of food vehicles to pathogenicity of disease-causing microorganisms is an important but overlooked research field. The current study was initiated to reveal the relationship between virulence of
    MeSH term(s) Animals ; Chickens/microbiology ; Egg Yolk/microbiology ; Mice ; Salmonella Infections ; Salmonella Infections, Animal/microbiology ; Salmonella enteritidis/genetics ; Virulence/genetics
    Language English
    Publishing date 2022-06-14
    Publishing country Switzerland
    Document type Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2619676-1
    ISSN 2235-2988 ; 2235-2988
    ISSN (online) 2235-2988
    ISSN 2235-2988
    DOI 10.3389/fcimb.2022.903979
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Sugar-Phosphate Toxicities.

    Boulanger, Erin F / Sabag-Daigle, Anice / Thirugnanasambantham, Pankajavalli / Gopalan, Venkat / Ahmer, Brian M M

    Microbiology and molecular biology reviews : MMBR

    2021  Volume 85, Issue 4, Page(s) e0012321

    Abstract: Accumulation of phosphorylated intermediates during cellular metabolism can have wide-ranging toxic effects on many organisms, including humans and the pathogens that infect them. These toxicities can be induced by feeding an upstream metabolite (a sugar, ...

    Abstract Accumulation of phosphorylated intermediates during cellular metabolism can have wide-ranging toxic effects on many organisms, including humans and the pathogens that infect them. These toxicities can be induced by feeding an upstream metabolite (a sugar, for instance) while simultaneously blocking the appropriate metabolic pathway with either a mutation or an enzyme inhibitor. Here, we survey the toxicities that can arise in the metabolism of glucose, galactose, fructose, fructose-asparagine, glycerol, trehalose, maltose, mannose, mannitol, arabinose, and rhamnose. Select enzymes in these metabolic pathways may serve as novel therapeutic targets. Some are conserved broadly among prokaryotes and eukaryotes (e.g., glucose and galactose) and are therefore unlikely to be viable drug targets. However, others are found only in bacteria (e.g., fructose-asparagine, rhamnose, and arabinose), and one is found in fungi but not in humans (trehalose). We discuss what is known about the mechanisms of toxicity and how resistance is achieved in order to identify the prospects and challenges associated with targeted exploitation of these pervasive metabolic vulnerabilities.
    MeSH term(s) Arabinose ; Galactose ; Humans ; Lactose ; Phosphates ; Xylose
    Chemical Substances Phosphates ; Xylose (A1TA934AKO) ; Arabinose (B40ROO395Z) ; Lactose (J2B2A4N98G) ; Galactose (X2RN3Q8DNE)
    Language English
    Publishing date 2021-09-29
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1376131-6
    ISSN 1098-5557 ; 1070-6275 ; 1092-2172
    ISSN (online) 1098-5557 ; 1070-6275
    ISSN 1092-2172
    DOI 10.1128/MMBR.00123-21
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Sugar-Phosphate Toxicities Attenuate Salmonella Fitness in the Gut.

    Boulanger, Erin F / Sabag-Daigle, Anice / Baniasad, Maryam / Kokkinias, Katherine / Schwieters, Andrew / Wrighton, Kelly C / Wysocki, Vicki H / Ahmer, Brian M M

    Journal of bacteriology

    2022  Volume 204, Issue 12, Page(s) e0034422

    Abstract: Pathogens are becoming resistant to antimicrobials at an increasing rate, and novel therapeutic strategies are needed. Using Salmonella as a model, we have investigated the induction of sugar-phosphate toxicity as a potential therapeutic modality. The ... ...

    Abstract Pathogens are becoming resistant to antimicrobials at an increasing rate, and novel therapeutic strategies are needed. Using Salmonella as a model, we have investigated the induction of sugar-phosphate toxicity as a potential therapeutic modality. The approach entails providing a nutrient while blocking the catabolism of that nutrient, resulting in the accumulation of a toxic intermediate. We hypothesize that this build-up will decrease the fitness of the organism during infection given nutrient availability. We tested this hypothesis using mutants lacking one of seven genes whose mutation is expected to cause the accumulation of a toxic metabolic intermediate. The
    MeSH term(s) Humans ; Animals ; Mice ; Drinking Water/metabolism ; Salmonella/genetics ; Salmonella enterica/genetics ; Sugars/metabolism ; Phosphates/metabolism
    Chemical Substances Drinking Water ; Sugars ; Phosphates
    Language English
    Publishing date 2022-11-16
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2968-3
    ISSN 1098-5530 ; 0021-9193
    ISSN (online) 1098-5530
    ISSN 0021-9193
    DOI 10.1128/jb.00344-22
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: Exposing new taxonomic variation with inflammation - a murine model-specific genome database for gut microbiome researchers.

    Leleiwi, Ikaia / Rodriguez-Ramos, Josué / Shaffer, Michael / Sabag-Daigle, Anice / Kokkinias, Katherine / Flynn, Rory M / Daly, Rebecca A / Kop, Linnea F M / Solden, Lindsey M / Ahmer, Brian M M / Borton, Mikayla A / Wrighton, Kelly C

    Microbiome

    2023  Volume 11, Issue 1, Page(s) 114

    Abstract: Background: The murine CBA/J mouse model widely supports immunology and enteric pathogen research. This model has illuminated Salmonella interactions with the gut microbiome since pathogen proliferation does not require disruptive pretreatment of the ... ...

    Abstract Background: The murine CBA/J mouse model widely supports immunology and enteric pathogen research. This model has illuminated Salmonella interactions with the gut microbiome since pathogen proliferation does not require disruptive pretreatment of the native microbiota, nor does it become systemic, thereby representing an analog to gastroenteritis disease progression in humans. Despite the value to broad research communities, microbiota in CBA/J mice are not represented in current murine microbiome genome catalogs.
    Results: Here we present the first microbial and viral genomic catalog of the CBA/J murine gut microbiome. Using fecal microbial communities from untreated and Salmonella-infected, highly inflamed mice, we performed genomic reconstruction to determine the impacts on gut microbiome membership and functional potential. From high depth whole community sequencing (~ 42.4 Gbps/sample), we reconstructed 2281 bacterial and 4516 viral draft genomes. Salmonella challenge significantly altered gut membership in CBA/J mice, revealing 30 genera and 98 species that were conditionally rare and unsampled in non-inflamed mice. Additionally, inflamed communities were depleted in microbial genes that modulate host anti-inflammatory pathways and enriched in genes for respiratory energy generation. Our findings suggest decreases in butyrate concentrations during Salmonella infection corresponded to reductions in the relative abundance in members of the Alistipes. Strain-level comparison of CBA/J microbial genomes to prominent murine gut microbiome databases identified newly sampled lineages in this resource, while comparisons to human gut microbiomes extended the host relevance of dominant CBA/J inflammation-resistant strains.
    Conclusions: This CBA/J microbiome database provides the first genomic sampling of relevant, uncultivated microorganisms within the gut from this widely used laboratory model. Using this resource, we curated a functional, strain-resolved view on how Salmonella remodels intact murine gut communities, advancing pathobiome understanding beyond inferences from prior amplicon-based approaches. Salmonella-induced inflammation suppressed Alistipes and other dominant members, while rarer commensals like Lactobacillus and Enterococcus endure. The rare and novel species sampled across this inflammation gradient advance the utility of this microbiome resource to benefit the broad research needs of the CBA/J scientific community, and those using murine models for understanding the impact of inflammation on the gut microbiome more generally. Video Abstract.
    MeSH term(s) Humans ; Animals ; Mice ; Gastrointestinal Microbiome/genetics ; Disease Models, Animal ; Mice, Inbred CBA ; Microbiota ; Inflammation ; Bacteroidetes
    Language English
    Publishing date 2023-05-20
    Publishing country England
    Document type Video-Audio Media ; Journal Article ; Research Support, U.S. Gov't, Non-P.H.S. ; Research Support, N.I.H., Extramural
    ZDB-ID 2697425-3
    ISSN 2049-2618 ; 2049-2618
    ISSN (online) 2049-2618
    ISSN 2049-2618
    DOI 10.1186/s40168-023-01529-7
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Editorial: LuxR Solos are Becoming Major Players in Cell-Cell Communication in Bacteria.

    Venturi, Vittorio / Ahmer, Brian M M

    Frontiers in cellular and infection microbiology

    2015  Volume 5, Page(s) 89

    MeSH term(s) Adaptation, Physiological ; Bacteria/genetics ; Bacteria/metabolism ; Gene Expression Regulation, Bacterial/drug effects ; Microbial Interactions ; Quorum Sensing ; Repressor Proteins/genetics ; Repressor Proteins/metabolism ; Stress, Physiological ; Trans-Activators/genetics ; Trans-Activators/metabolism
    Chemical Substances Repressor Proteins ; Trans-Activators ; LuxR autoinducer binding proteins (115038-68-1)
    Language English
    Publishing date 2015
    Publishing country Switzerland
    Document type Editorial ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 2619676-1
    ISSN 2235-2988 ; 2235-2988
    ISSN (online) 2235-2988
    ISSN 2235-2988
    DOI 10.3389/fcimb.2015.00089
    Database MEDical Literature Analysis and Retrieval System OnLINE

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