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Journal of Applied Microbiology Sep 2013The aim of this study was to use a sensitive method to screen and quantify 57 Vibrionaceae strains for the production of acyl-homoserine lactones (AHLs) and map the...
AIMS
The aim of this study was to use a sensitive method to screen and quantify 57 Vibrionaceae strains for the production of acyl-homoserine lactones (AHLs) and map the resulting AHL profiles onto a host phylogeny.
METHODS AND RESULTS
We used a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) protocol to measure AHLs in spent media after bacterial growth. First, the presence/absence of AHLs (qualitative analysis) was measured to choose internal standard for subsequent quantitative AHL measurements. We screened 57 strains from three genera (Aliivibrio, Photobacterium and Vibrio) of the same family (i.e. Vibrionaceae). Our results show that about half of the isolates produced multiple AHLs, typically at 25-5000 nmol l(-1) .
CONCLUSIONS
This work shows that production of AHL quorum sensing signals is found widespread among Vibrionaceae bacteria and that closely related strains typically produce similar AHL profiles.
SIGNIFICANCE AND IMPACT OF THE STUDY
The AHL detection protocol presented in this study can be applied to a broad range of bacterial samples and may contribute to a wider mapping of AHL production in bacteria, for example, in clinically relevant strains.
Topics: Acyl-Butyrolactones; Aliivibrio fischeri; Chromatography, High Pressure Liquid; Mass Spectrometry; Photobacterium; Quorum Sensing; Tandem Mass Spectrometry; Vibrio; Vibrionaceae
PubMed: 23725044
DOI: 10.1111/jam.12264 -
Proceedings of the National Academy of... May 2024Several microbial genomes lack textbook-defined essential genes. If an essential gene is absent from a genome, then an evolutionarily independent gene of unknown...
Several microbial genomes lack textbook-defined essential genes. If an essential gene is absent from a genome, then an evolutionarily independent gene of unknown function complements its function. Here, we identified frequent nonhomologous replacement of an essential component of DNA replication initiation, a replicative helicase loader gene, in . Our analysis of genomes revealed two genes with unknown function, named and , that were substantially enriched in genomes without the known helicase-loader genes. These genes showed no sequence similarities to genes with known function but encoded proteins structurally similar with a viral helicase loader. Analyses of genomic syntenies and coevolution with helicase genes suggested that encodes a helicase loader. The in vitro assay showed that VdhL1 and VdhL2 promote the helicase activity of DnaB. Furthermore, molecular phylogenetics suggested that / were derived from phages and replaced an intrinsic helicase loader gene of over 20 times. This high replacement frequency implies the host's advantage in acquiring a viral helicase loader gene.
Topics: Vibrionaceae; DNA Helicases; DNA Replication; Phylogeny; Bacterial Proteins; Viral Proteins; Bacteriophages; Evolution, Molecular; Genome, Bacterial; DnaB Helicases; Vibrio
PubMed: 38683976
DOI: 10.1073/pnas.2317954121 -
The Journal of Antimicrobial... Dec 2005To gain insight into the functionality of qnr-like genes of several bacterial species of Vibrionaceae that may encode quinolone resistance determinants.
OBJECTIVES
To gain insight into the functionality of qnr-like genes of several bacterial species of Vibrionaceae that may encode quinolone resistance determinants.
METHODS
A PCR-based strategy was used to obtain qnr-like genes of reference strains of Vibrio vulnificus CIP103196, Vibrio parahaemolyticus CIP71.2 and Photobacterium profundum CIP106289 that were sequenced, cloned and expressed in Escherichia coli. MICs of quinolones were determined for these reference strains and an E. coli reference strain harbouring recombinant plasmids.
RESULTS
The Qnr-like proteins of these Vibrionaceae bacterial species shared 40-67% amino acid identity with the plasmid-mediated quinolone resistance determinants QnrA, QnrB and QnrS with a series of highly conserved residues. Once cloned in E. coli they conferred reduced susceptibility to quinolones.
CONCLUSIONS
This work provides further evidence that water-borne Vibrionaceae may constitute a reservoir for Qnr-like quinolone resistance determinants.
Topics: Amino Acid Sequence; Anti-Bacterial Agents; Bacterial Proteins; DNA, Bacterial; Drug Resistance, Bacterial; Escherichia coli; Gene Transfer, Horizontal; Genes, Bacterial; Microbial Sensitivity Tests; Molecular Sequence Data; Photobacterium; Polymerase Chain Reaction; Quinolones; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Vibrio parahaemolyticus; Vibrio vulnificus; Vibrionaceae
PubMed: 16227349
DOI: 10.1093/jac/dki371 -
Folia Microbiologica Nov 2016Multiple symbiotic and free-living Vibrio spp. grow as a form of microbial community known as a biofilm. In the laboratory, methods to quantify Vibrio biofilm mass... (Comparative Study)
Comparative Study
Multiple symbiotic and free-living Vibrio spp. grow as a form of microbial community known as a biofilm. In the laboratory, methods to quantify Vibrio biofilm mass include crystal violet staining, direct colony-forming unit (CFU) counting, dry biofilm cell mass measurement, and observation of development of wrinkled colonies. Another approach for bacterial biofilms also involves the use of tetrazolium (XTT) assays (used widely in studies of fungi) that are an appropriate measure of metabolic activity and vitality of cells within the biofilm matrix. This study systematically tested five techniques, among which the XTT assay and wrinkled colony measurement provided the most reproducible, accurate, and efficient methods for the quantitative estimation of Vibrionaceae biofilms.
Topics: Bacteriological Techniques; Biofilms; Vibrionaceae
PubMed: 27009592
DOI: 10.1007/s12223-016-0456-9 -
International Journal of Molecular... Aug 2022Piscibactin is a widespread siderophore system present in many different bacteria, especially within the family. Previous works showed that most functions required for...
Piscibactin is a widespread siderophore system present in many different bacteria, especially within the family. Previous works showed that most functions required for biosynthesis and transport of this siderophore are encoded by the high-pathogenicity island -HPI. In the present work, using as a model, we could identify additional key functions encoded by -HPI that are necessary for piscibactin production and transport and that have remained unknown. Allelic exchange mutagenesis, combined with cross-feeding bioassays and LC-MS analysis, were used to demonstrate that Irp4 protein is an essential component for piscibactin synthesis since it is the thioesterase required for nascent piscibactin be released from the NRPS Irp1. We also show that Irp8 is a MFS-type protein essential for piscibactin secretion. In addition, after passage through the outer membrane transporter FrpA, the completion of ferri-piscibactin internalization through the inner membrane would be achieved by the ABC-type transporter FrpBC. The expression of this transporter is coordinated with the expression of FrpA and with the genes encoding biosynthetic functions. Since piscibactin is a major virulence factor of some pathogenic vibrios, the elements of biosynthesis and transport described here could be additional interesting targets for the design of novel antimicrobials against these bacterial pathogens.
Topics: Bacterial Proteins; Genomic Islands; Siderophores; Vibrio; Vibrionaceae; Virulence Factors
PubMed: 36012135
DOI: 10.3390/ijms23168865 -
Scientific Data Jul 2018Viruses are highly discriminating in their interactions with host cells and are thought to play a major role in maintaining diversity of environmental microbes. However,...
Viruses are highly discriminating in their interactions with host cells and are thought to play a major role in maintaining diversity of environmental microbes. However, large-scale ecological and genomic studies of co-occurring virus-host pairs, required to characterize the mechanistic and genomic foundations of virus-host interactions, are lacking. Here, we present the largest dataset of cultivated and sequenced co-occurring virus-host pairs that captures ecologically representative fine-scale diversity. Using the ubiquitous and ecologically diverse marine Vibrionaceae as a host platform, we isolate and sequence 251 dsDNA viruses and their hosts from three time points within a 93-day time-series study. The virus collection includes representatives of the three Caudovirales tailed virus morphotypes, a novel family of nontailed viruses, and the smallest (10,046 bp) and largest (348,911 bp) Vibrio virus genomes described. We provide general characterization and annotation of the viruses and describe read-mapping protocols to standardize genome presentation. The rich ecological and genomic contextualization of hosts and viruses make the Nahant Collection a unique platform for high-resolution studies of environmental virus-host infection networks.
Topics: Caudovirales; Ecology; Genome, Viral; Host-Pathogen Interactions; Vibrionaceae; Viruses
PubMed: 29969110
DOI: 10.1038/sdata.2018.114 -
PLoS Genetics Apr 2021Quorum sensing (QS) is a process of chemical communication bacteria use to transition between individual and collective behaviors. QS depends on the production, release,...
Quorum sensing (QS) is a process of chemical communication bacteria use to transition between individual and collective behaviors. QS depends on the production, release, and synchronous response to signaling molecules called autoinducers (AIs). The marine bacterium Vibrio harveyi monitors AIs using a signal transduction pathway that relies on five small regulatory RNAs (called Qrr1-5) that post-transcriptionally control target genes. Curiously, the small RNAs largely function redundantly making it difficult to understand the necessity for five of them. Here, we identify LuxT as a transcriptional repressor of qrr1. LuxT does not regulate qrr2-5, demonstrating that qrr genes can be independently controlled to drive unique downstream QS gene expression patterns. LuxT reinforces its control over the same genes it regulates indirectly via repression of qrr1, through a second transcriptional control mechanism. Genes dually regulated by LuxT specify public goods including an aerolysin-type pore-forming toxin. Phylogenetic analyses reveal that LuxT is conserved among Vibrionaceae and sequence comparisons predict that LuxT represses qrr1 in additional species. The present findings reveal that the QS regulatory RNAs can carry out both shared and unique functions to endow bacteria with plasticity in their output behaviors.
Topics: Bacterial Proteins; DNA-Binding Proteins; Escherichia coli; Genes, Regulator; Phylogeny; Quorum Sensing; RNA, Messenger; Regulatory Sequences, Ribonucleic Acid; Signal Transduction; Vibrio cholerae; Vibrionaceae
PubMed: 33793568
DOI: 10.1371/journal.pgen.1009336 -
Environmental Microbiology Jan 2011Although animal-associated microbial communities (microbiomes) are increasingly recognized to influence health, the extent to which animals represent highly selective...
Although animal-associated microbial communities (microbiomes) are increasingly recognized to influence health, the extent to which animals represent highly selective habitats for microbes leading to predominance of high host specificity remains poorly understood. Here, we show that vibrios, which are well-known commensals and opportunistic pathogens of marine animals, overall display little host preference, likely because of efficient dispersal-colonization dynamics mediated by food items. We isolated 1753 strains from water and animal samples, which are linked in a food chain and display different degrees of similarity (respiratory and digestive tract of mussels and crabs, live and dead zooplankton, and whole water samples). Multilocus sequence data served as input for modelling and statistical analysis of spatiotemporal population structure. These data showed that the majority of populations occurred broadly within and among hosts, with the dominant population being a near perfect generalist with regard to seasons, host taxa and body regions. Zooplankton harboured the fewest and most specific populations, while crabs and mussels contained the highest diversity with little evidence for host preferences. Most mussel- and crab-associated populations were detected in water samples at similar frequencies, particularly in filter-feeding mussels where populations were also evenly distributed across host individuals. The higher variation among individuals observed in crabs and zooplankton is consistent with stochastic clonal expansions. These patterns suggest that evolution of a high degree of host specificity is surprisingly rare even though these animals represent long-lived habitats, and vibrios are consistent members of their microbiome. Instead, many of the populations show stronger association with planktonic (micro)habitats while the microbiome may be a fairly open system for vibrios in which high rates of immigration can outpace selection for specialization.
Topics: Animals; Host Specificity; Invertebrates; Multilocus Sequence Typing; Phylogeny; Seasons; Seawater; Vibrionaceae; Water Microbiology
PubMed: 20819104
DOI: 10.1111/j.1462-2920.2010.02328.x -
Nucleic Acids Research Apr 2024Integrons are genetic platforms that acquire new genes encoded in integron cassettes (ICs), building arrays of adaptive functions. ICs generally encode promoterless...
Integrons are genetic platforms that acquire new genes encoded in integron cassettes (ICs), building arrays of adaptive functions. ICs generally encode promoterless genes, whose expression relies on the platform-associated Pc promoter, with the cassette array functioning as an operon-like structure regulated by the distance to the Pc. This is relevant in large sedentary chromosomal integrons (SCIs) carrying hundreds of ICs, like those in Vibrio species. We selected 29 gene-less cassettes in four Vibrio SCIs, and explored whether their function could be related to the transcription regulation of adjacent ICs. We show that most gene-less cassettes have promoter activity on the sense strand, enhancing the expression of downstream cassettes. Additionally, we identified the transcription start sites of gene-less ICs through 5'-RACE. Accordingly, we found that most of the superintegron in Vibrio cholerae is not silent. These promoter cassettes can trigger the expression of a silent dfrB9 cassette downstream, increasing trimethoprim resistance >512-fold in V. cholerae and Escherichia coli. Furthermore, one cassette with an antisense promoter can reduce trimethoprim resistance when cloned downstream. Our findings highlight the regulatory role of gene-less cassettes in the expression of adjacent cassettes, emphasizing their significance in SCIs and their clinical importance if captured by mobile integrons.
Topics: Integrons; Promoter Regions, Genetic; Vibrio; Vibrio cholerae; Vibrionaceae
PubMed: 38214222
DOI: 10.1093/nar/gkad1252 -
Photochemistry and Photobiology Oct 1995
Comparative Study Review
Topics: Energy Transfer; Fluorescence; Luciferases; Luminescence; Luminescent Proteins; Photobacterium; Seawater; Vibrio; Vibrionaceae
PubMed: 7480148
DOI: 10.1111/j.1751-1097.1995.tb08708.x