Bacteria cycle between periods when they perform individual behaviors and group behaviors. These transitions are controlled by a cell-cell communication process called quorum sensing, in which extracellular signal molecules, autoinducers (AIs), released, accumulate, synchronously detected of bacteria. AI detection results community-wide changes gene expression, enabling bacteria to collectively execute such as bioluminescence, biofilm formation, virulence factor production. In this study, we...

Advances in DNA sequencing technology have facilitated the determination of hundreds complete genome sequences both for bacteria and their bacteriophages. Some these well-developed facile genetic systems constructing mutants to determine gene function, recombineering is a particularly effective tool. However, generally applicable methods defined bacteriophages are poorly developed, part because inability use selectable markers such as drug resistance genes during viral lytic growth. Here we...

Summary Construction of genetically isogenic strains mycobacteria is complicated by poor recombination rates and the lack generalized transducing phages for Mycobacterium tuberculosis . We report here a powerful method introducing single point mutations into mycobacterial genomes using oligonucleotide‐derived single‐stranded DNA recombineering mycobacteriophage‐encoded proteins. Phage Che9c gp61‐mediated sufficiently efficient that base changes can be introduced without requirement direct...

ABSTRACT Bacteria use a chemical communication process called quorum sensing to control transitions between individual and group behaviors. In the Vibrio harveyi quorum-sensing circuit, two master transcription factors, AphA LuxR, coordinate response. Here we show that regulates 167 genes, LuxR 625 they coregulate 77 genes. strongly controls genes at both low cell density high density, suggesting it is major regulator. contrast, absent acts fine-tune gene expression density. We examined loci...

ABSTRACT LuxR-type transcription factors are the master regulators of quorum sensing in vibrios. LuxR proteins unique members TetR superfamily because they activate and repress large regulons genes. Here, we used chromatin immunoprecipitation nucleotide sequencing (ChIP-seq) to identify binding sites Vibrio harveyi genome. Bioinformatics analyses showed that consensus site at repressed promoters is a symmetric palindrome, whereas activated it asymmetric contains only half palindrome. Using...

Vibrio coralliilyticus is a pathogen of coral and shellfish, leading to devastating economic ecological consequences worldwide. Although rising ocean temperatures correlate with increased V . pathogenicity, the specific molecular mechanisms determinants contributing virulence remain poorly understood. Here, we systematically analyzed type VI secretion system (T6SS), contact-dependent toxin delivery apparatus, in We identified 2 omnipresent T6SSs that are activated at which becomes virulent;...

CRISPRi (Clustered Regularly Interspaced Palindromic Repeats interference) is a gene knockdown method that uses deactivated Cas9 protein (dCas9) binds specific target locus dictated by an encoded guide RNA (sgRNA) to block transcription. Mobile-CRISPRi suite of modular vectors enable knockdowns in diverse bacteria integrating IPTG-inducible

The cell-cell signaling process called quorum sensing allows bacteria to control behaviors in response changes population density. In Vibrio harveyi, the master quorum-sensing transcription factor LuxR is a member of TetR family factors that both activates and represses genes coordinate group behaviors, including bioluminescence. Here, we show integration host (IHF) key coactivator luxCDABE bioluminescence required together with for precise timing expression levels during sensing. IHF binds...

The bacterial pathogen Vibrio coralliilyticus causes disease in coral species worldwide. mechanisms of V. colonization, microbiome interactions, and virulence factor production are understudied. In other model species, factors like biofilm formation, toxin secretion, protease controlled through a density-dependent communication system called quorum sensing (QS). Comparative genomics indicated that genomes share high sequence identity for most the QS signaling regulatory components identified...

ABSTRACT The type III secretion system (T3SS) is a needle-like complex used by numerous bacterial pathogens in host infection to inject exotoxins into the cell cytoplasm. T3SS known virulence factor shrimp pathogen Vibrio campbellii . ~40 genes comprising V. are regulated network of transcription factors response changes cell’s environment: density (quorum sensing; QS), temperature, calcium, and contact. Under positive environmental stimuli, master ExsA activates expression four structural...

ABSTRACT Bacteria use a chemical communication process called quorum sensing to monitor cell density and alter behavior in response fluctuations population numbers. Previous studies with Vibrio harveyi have shown that LuxR, the master quorum-sensing regulator, activates represses >600 genes. These include six genes encode homologs of Escherichia coli Bet ProU systems for synthesis transport, respectively, glycine betaine, an osmoprotectant used during osmotic stress. Here we show LuxR...

In Vibrio species, chitin-induced natural transformation enables bacteria to take up DNA from the external environment and integrate it into their genome. Expression of master competence regulator TfoX bypasses need for chitin induction drives expression genes required in several species. Here, we show that campbellii strains DS40M4 NBRC 15631 high frequencies. Conversely, was not achieved model quorum-sensing strain V. BB120 (previously classified as harveyi). Surprisingly, find quorum...

Bacteria coordinate cellular behaviors using a cell-cell communication system termed quorum sensing. In Vibrio harveyi, the master sensing transcription factor LuxR directly regulates >100 genes in response to changes population density. Here, we show that derepresses loci by competing with H-NS, global transcriptional repressor oligomerizes on DNA form filaments and bridges. We first identified H-NS as of bioluminescence gene expression, for which is required activator. an hns deletion...

Summary In Vibrio species, quorum sensing controls gene expression for numerous group behaviors, including bioluminescence production, biofilm formation, virulence factor secretion systems, and competence. The LuxR/HapR master quorum‐sensing regulators activate of hundreds genes in response to changes population densities. mechanism transcription activation by these TetR‐type factors is unknown, though LuxR DNA binding sites that lie close proximity the −35 region promoter are required at...

Vibrio campbellii is a Gram-negative bacterium that free-living and ubiquitous in marine environments an important global pathogen of fish shellfish. Disruption the flagellar motor significantly decreases host mortality V. , suggesting motility key factor pathogenesis.

Many bacteria use quorum sensing to control changes in lifestyle. The process is regulated by microbially derived 'autoinducer' signalling molecules, that accumulate the local environment. Individual cells sense autoinducer abundance, infer population density, and alter their behaviour accordingly. In Vibrio cholerae, quorum-sensing signals are transduced phosphorelay transcription factor LuxO. Unphosphorylated LuxO permits expression of HapR, which alters global gene patterns. this work, we...

Abstract CRISPRi (Clustered Regularly Interspaced Palindromic Repeats interference) is a gene knockdown method that uses deactivated Cas9 protein (dCas9) binds specific target locus dictated by an encoded guide RNA (sgRNA) to block transcription. Mobile-CRISPRi suite of modular vectors enable knockdowns in diverse bacteria integrating IPTG-inducible dcas9 and sgRNA genes into the genome using Tn 7 transposition. Here, we show system functions robustly specifically multiple Vibrio species:...

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Abstract Vibrio coralliilyticus ( Vcor ) is a pathogen of coral and shellfish, leading to devastating economic ecological consequences worldwide. Although rising ocean temperatures correlate with increased pathogenicity, the specific molecular mechanisms determinants contributing virulence remain poorly understood. Here, we systematically analyzed type VI secretion system (T6SS), contact-dependent toxin delivery apparatus, in . We identified two omnipresent T6SSs that are activated at which...

Bio-orthogonal non-canonical amino acid tagging allows time-resolved proteomic analysis of quorum sensing in<italic>Vibrio harveyi</italic>.