Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

An epigenetic switch activates bacterial quorum sensing and horizontal transfer of an integrative and conjugative element

ABSTRACT: Horizontal transfer of the integrative and conjugative element ICEMlSymR7A converts non symbiotic Mesorhizobium spp. into nitrogen-fixing legume symbionts. Here we discover subpopulations of Mesorhizobium japonicum R7A become epigenetically primed for quorum-sensing (QS) and QS-activated horizontal transfer. Isolated populations in this state termed R7A* maintained these phenotypes in laboratory culture but did not transfer the R7A* state to recipients of ICEMlSymR7A following conjugation. We previously demonstrated ICEMlSymR7A transfer and QS are repressed by the antiactivator QseM in R7A populations and that the adjacently-coded DNA-binding protein QseC can represses qseM transcription. Here RNA-sequencing revealed qseM expression was repressed in R7A* cells and that RNA antisense to qseC was abundant in R7A but not R7A*. Deletion of the antisense-qseC promoter converted cells into an R7A*-like state. An adjacently-coded QseC2 protein bound two operator sites and repressed antisense-qseC transcription. Plasmid overexpression of QseC2 stimulated the R7A* state, which persisted following curing of this plasmid. The epigenetic maintenance of the R7A* state required ICEMlSymR7A-encoded copies of both qseC and qseC2. Therefore QseC and QseC2, together with their DNA-binding sites and overlapping promoters, form a stable epigenetic switch that establishes binary control over qseM transcription and primes a subpopulation of R7A cells for QS and horizontal transfer.

ORGANISM(S): Mesorhizobium japonicum

PROVIDER: GSE189468 | GEO | 2021/11/26

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Vertical and horizontal gene transfer tradeoffs direct plasmid fitness

Project description:Plasmid fitness is directed by two orthogonal processes—vertical transfer through cell division and horizontal transfer through conjugation. When considered individually, improvements in either mode of transfer can promote how well a plasmid spreads and persists. Together, however, the metabolic cost of conjugation could create a tradeoff that constrains plasmid evolution. Here we present evidence for the presence, consequences, and molecular basis of a conjugation-growth tradeoff across 40 plasmids derived from clinical E. coli pathogens. We discover that most plasmids operate below a conjugation efficiency threshold for major growth effects, indicating strong natural selection for vertical transfer. Below this threshold, E. coli demonstrates a remarkable growth tolerance to over four orders of magnitude change in conjugation efficiency. This tolerance fades as nutrients become scarce and horizontal transfer attracts a greater share of host resources. Our results provide insight into evolutionary constraints directing plasmid fitness and strategies to combat the spread of antibiotic resistance.

2022-12-23 | GSE219270 | GEO

A small RNA controlled AND-gate regulates extrachromosomal DNA transfer in Salmonella

Project description:Horizontal gene transfer via plasmid conjugation is a major driving force in microbial evolution. Transfer of conjugative plasmids is a complex process that needs to be synchronized with the physiological state of the bacterial host. While several host transcription factors are known to control the plasmid-borne transfer control genes, RNA-based regulatory circuits for host-plasmid communication remain unknown. Here, we describe a post-transcriptional mechanism whereby the Hfq-dependent small RNA, RprA, inhibits transfer of pSLT, the virulence plasmid of Salmonella enterica. RprA employs two different seed pairing domains to recognize and activate the mRNAs of both the sigma-factor S and RicI, a cytoplasmic membrane protein. The latter is a hitherto unknown conjugation inhibitor whose transcription requires S. Together, RprA and S constitute a feed-forward loop with AND-gate logic which tightly controls RicI synthesis for selective suppression of plasmid conjugation under membrane stress. This study reports the first sRNA-controlled feed-forward loop based on double target activation and an unexpected function for a core-genome encoded small RNA in controlling extrachromosomal DNA transfer.

2015-03-24 | GSE67187 | GEO

Prevalence of multi-resistant plasmids in hospital inhalable particulate matter (PM) and its impact on horizontal gene transfer

Project description:Antibiotic resistance is exacerbated by the exchange of antibiotic resistance genes (ARGs) between microbes from diverse habitats. Plasmids are important ARGs mobile elements and are spread by horizontal gene transfer (HGT). In this study, we demonstrated the presence of multi-resistant plasmids from inhalable particulate matter (PM) and its effect on gene horizontal transfer. Three transferable multi-resistant plasmids were identified from PM in a hospital, using conjugative mating assays and nanopore sequencing. pTAir-3 contained 26 horizontal transfer elements and 10 ARGs. Importantly pTAir-5 harbored carbapenem resistance gene (blaOXA) which shows homology to plasmids from human and pig commensal bacteria, thus indicating that PM is a media for antibiotic resistant plasmid spread. In addition, 125 μg/mL PM2.5 and PM10 significantly increased the conjugative transfer rate by 110% and 30%, respectively, and augmented reactive oxygen species (ROS) levels. Underlying mechanisms were revealed by identifying the upregulated expressional levels of genes related to ROS, SOS, cell membranes, pilus generation, and transposition via genome-wide RNA sequencing. The study highlights the airborne spread of multi-resistant plasmids and the impact of inhalable PM on the horizontal transfer of antibiotic resistance.

2022-10-31 | GSE159850 | GEO

Plasmid-encoded toxin defence mediates mutualistic microbial interactions

Project description:<p>Gut environments harbour dense microbial ecosystems in which plasmids are widely distributed. Plasmids facilitate the exchange of genetic material among microorganisms while enabling the transfer of a diverse array of accessory functions. However, their precise impact on microbial community composition and function remains largely unexplored. Here we identify a prevalent bacterial toxin and a plasmid-encoded resistance mechanism that mediates the interaction between Lactobacilli and Enterococci. This plasmid is widespread across ecosystems, including the rumen and human gut microbiota. Biochemical characterization of the plasmid revealed a defence mechanism against reuterin, a toxin produced by various gut microbes, such as Limosilactobacillus reuteri. Using a targeted metabolomic approach, we find reuterin to be prevalent across rumen ecosystems with impacts on microbial community structure. Enterococcus strains carrying the protective plasmid were isolated and their interactions with L. reuteri, the toxin producer, were studied in vitro. Interestingly, we found that by conferring resistance against reuterin, the plasmid mediates metabolic exchange between the defending and the attacking microbial species, resulting in a beneficial relationship or mutualism. Hence, we reveal here an ecological role for a plasmid-coded defence system in mediating a beneficial interaction. </p>

2023-08-10 | MTBLS7248 | MetaboLights

High-resolution mapping of the pCAR1 plasmid transcriptomes in Pseudomonas

Project description:High-resolution mapping of the pCAR1 plasmid transcriptomes in the original host Pseudomonas resinovorans CA10 and the transconjugant Pseudomonas putida KT2440(pCAR1) While plasmids are replicated autonomously in their hosts, the transcription of plasmid genes can be switched through horizontal transfer by the change in the transcriptional networks. To examine whether and how the plasmid genome is differentially expressed, we analyzed the transcriptomes of the 199,035-bp IncP-7 carbazole catabolic and conjugative plasmid pCAR1 in the original host Pseudomonas resinovorans CA10 and the transconjugant Pseudomonas putida KT2440(pCAR1) during growth on carbazole or succinate using the high-resolution tiling array. The tiling array successfully detected the relatively large catabolic operons, for which transcription was induced during growth on carbazole regardless of the host. Compared between the hosts, nearly identical regions of pCAR1 were transcribed, but two hypothetical operons, i.e., ORF100-108 and ORF145-146, were transcribed at higher levels in KT2440(pCAR1) than in CA10. We verified the differential expression in heterologous hosts using quantitative RT-PCR. The tiling array analysis clearly revealed the transcription start sites, for which the positions and extents agreed with the primer extension experiments. Our data demonstrate that the transcriptome of the transmissible plasmid is altered through horizontal transfer, and we identified probable genes that are involved in plasmid functions in various hosts. This approach can be used to visualize flexible prokaryotic transcriptomes comprehensively. Keywords: high-resolution RNA mapping

2008-10-18 | GSE10862 | GEO

Proteomics profiling of xanthomonas retroflexus colony variants

Project description:Plasmid conjugation is a key facilitator of horizontal gene transfer. Since plasmids often carry antibiotic resistance genes, they are crucial drivers of the world-wide rise of antibiotic resistance among pathogens. In natural, engineered and clinical environments, bacteria often grow in protective biofilms. Therefore, a better understanding of plasmid transfer in biofilms is needed. Our aim was to investigate plasmid transfer in a biofilm adapted wrinkly colony mutant of Xanthomonas retroflexus (XRw) with enhanced matrix production and reduced motility. We found that XRw biofilms had an increased uptake of the broad host-range IncP-1ϵ plasmid pKJK5 compared to the wild type. Proteomics revealed fewer flagellum associated proteins in XRw, suggesting that flagella were responsible for reducing plasmid uptake. This was confirmed by the higher plasmid uptake of non-flagellated ∆fliM mutants of X. retroflexus wild type and wrinkly mutant. Moreover, testing several flagella mutants of Pseudomonas putida suggested that the flagella effect was more general. We identified seven mechanisms with the potential to explain the flagella effect and simulated them in an individual-based model. Two mechanisms could thus be eliminated (increased distances between cells and increased lag times due to flagella). Another mechanism identified as viable in the modelling was eliminated by further experiments. Four additional proposed mechanisms have a reduced probability of plasmid transfer in common. Our findings highlight the important yet complex effects of flagella during bacterial conjugation in biofilms.

2024-01-26 | PXD040461 | Pride

RcgA and RcgR, two novel proteins involved in conjugative transfer of rhizobial plasmids

Project description:Rhizobia are gram-negative bacteria able to establish a symbiotic interaction with leguminous plants. Due to their nitrogen fixing capacity, the study of these microorganisms has acquired great relevance for the agriculture. Rhizobia usually harbor many plasmids in their genome which can be transferred to other organisms by conjugation. Two main mechanisms of regulation of rhizobial plasmid transfer have been described: Quorum sensing (QS) and rctA/rctB system. Nevertheless, new genes and molecules that modulate conjugative transfer have been recently described, demonstrating that new actors can tightly regulate the process. In this work, by means of bioinformatics tools and molecular biology approaches, two hypothetical genes are identified as playing key roles in conjugative transfer. These genes are located between conjugative genes of plasmid pLPU83a from Rhizobium favelukesii LPU83, a plasmid that showed a conjugative transfer behavior depending on the genomic background. One of the two mentioned genes, rcgA, is essential for conjugation, while the other, rcgR, acts as an inhibitor of the process. In addition to introducing this new regulatory mechanism, we show evidence of the functions of these genes in different genomic backgrounds, and confirmed that homologous proteins from non-closely related organisms play the same function. These findings set up a cornerstone for a new molecular circuit of conjugative transfer of plasmids.

2022-08-29 | PXD033583 | Pride

Treatment with Cefotaxime Affects Expression of Conjugation Associated Proteins and Conjugation Transfer Frequency of an IncI1 Plasmid in Escherichia coli

Project description:Horizontal gene transfer (HGT) is the major mechanism responsible for spread of antibiotic resistance. Antibiotic treatment has been suggested to promote HGT, either by directly affecting the conjugation process itself or by selecting for conjugations subsequent to DNA transfer. However, recent research suggests that the effect of antibiotic treatment on plasmid conjugation frequencies, and hence the spread of resistance plasmids, may have been overestimated. We addressed the question by quantifying transfer proteins and conjugation frequencies of a blaCTX-M-1 encoding IncI1 resistance plasmid in Escherichia coli MG1655 in the presence and absence of therapeutically relevant concentrations of cefotaxime (CTX). Analysis of the proteome by iTRAQ labeling and liquid chromatography tandem mass spectrometry revealed that Tra proteins were significantly up regulated in the presence of CTX. The up-regulation of the transfer machinery was confirmed at the transcriptional level for five selected genes. The CTX treatment did not cause induction of the SOS39 response as revealed by absence of significantly regulated SOS associated proteins in the proteome and no significant up-regulation of recA and sfiA genes. The frequency of plasmid conjugation, measured in an antibiotic free environment, increased significantly when the donor was pre-grown in broth containing CTX compared to growth without this drug, regardless of whether blaCTX-M-1 was located on the plasmid or in trans on the chromosome. The results shows that antibiotic treatment can affect expression of a plasmid conjugation machinery and subsequent DNA transfer.

2017-11-21 | PXD006679 | Pride

Conjugation, genetic reprogamming and horizontal transfer of pathogenicity between Roseobacters

Project description:Horizontal transfer of plasmids is one of the main drivers of bacterial adaptation, resulting e.g. in the spread of antibiotic resistance. We investigated the marine Roseobacter group and studied how conjugation affects the gene expression and biology of the new host. We showed that the two syntenic 126 kb and 191 kb plasmids of Dinoroseobacter shibae can be conjugated into representatives of all major lineages of Rhodobacteraceae. In the model organism Phaeobacter inhibens their acquisition resulted in differential expression of genes related to motility, transport and the synthesis of vitamins. Moreover, the decrease of the potent antibiotic tropodithietic acid reduced the energetic burden of Phaeobacter and resulted in an enhanced growth. While the T4SS systems of both plasmids were silenced in the new host, the ability to kill the dinoflagellate was exclusively transferred via the 191 kb plasmid from D. shibae to P. inhibens. Our findings showed drastic consequences of plasmid conjugation; genetic reprogramming of the novel host resulted in considerable fitness changes leading to the prediction that horizontal gene transfer triggers bacterial speciation.

2019-05-01 | GSE126149 | GEO