Protocols for Visualizing Horizontal Gene Transfer in Gram-Negative Bacteria Through Natural Competence

2015 ◽  
pp. 189-204
Author(s):  
Melanie Blokesch
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Gram Negative Bacteria ◽  
Natural Competence ◽  
Gram Negative

Type III Secretion: More Systems Than You Think

Physiology ◽  
2005 ◽  
Vol 20 (5) ◽  
pp. 326-339 ◽  
Author(s):  
Paul Troisfontaines ◽  
Guy R. Cornelis
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Type Iii Secretion ◽  
Plant Cells ◽  
Effector Proteins ◽  
Eukaryotic Cells ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Type Iii ◽  
Target Animal

The type III secretion (T3S) pathway allows bacteria to inject effector proteins into the cytosol of target animal or plant cells. T3S systems evolved into seven families that were distributed among Gram-negative bacteria by horizontal gene transfer. There are probably a few hundred effectors interfering with control and signaling in eukaryotic cells and offering a wealth of new tools to cell biologists.

Integron Class 1 Reservoir among Highly Resistant Gram-Negative Microorganisms Recovered at a Dutch Teaching Hospital

2009 ◽  
Vol 30 (10) ◽  
pp. 1015-1018 ◽  
Author(s):  
Marlies J. Mooij ◽  
Ina Willemsen ◽  
Marihe Lobbrecht ◽  
Christina Vandenbroucke-Grauls ◽  
Jan Kluytmans ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Resistance Genes ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Gram Negative Bacteria ◽  
Care Hospital ◽  
Gram Negative ◽  
Class 1 ◽  
Cross Transmission

Integrons play an important role in the dissemination of resistance genes among bacteria. Nearly 70% of highly resistant gram-negative bacteria isolated at a tertiary care hospital harbored an integron. Epidemiologic analysis suggests that horizontal gene transfer is an important mechanism of resistance spread and has a greater contribution than cross-transmission to levels of resistance in settings where highly resistant gram-negative bacteria are endemic.

scholarly journals Mobilization of Plasmids and Chromosomal DNA Mediated by the SXT Element, a Constin Found in Vibrio cholerae O139

2000 ◽  
Vol 182 (7) ◽  
pp. 2043-2047 ◽  
Author(s):  
Bianca Hochhut ◽  
Joeli Marrero ◽  
Matthew K. Waldor
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Vibrio Cholerae ◽  
Gram Negative Bacteria ◽  
Chromosomal Dna ◽  
General Role ◽  
Gram Negative ◽  
Vibrio Cholerae O139 ◽  
Multiple Antibiotics

ABSTRACT The Vibrio cholerae SXT element encodes resistance to multiple antibiotics and is a conjugative, self-transmissible, and chromosomally integrating element (a constin). Excision and self-transfer of the SXT element require an element-encoded integrase. We now report that the SXT element can also mobilize the plasmids RSF1010 and CloDF13 in trans as well as chromosomal DNA in an Hfr-like manner. SXT element-mediated mobilization of plasmids and chromosomal DNA, unlike its self-transfer, is not dependent upon excision of the element from the chromosome. These results raise the possibility that the SXT element and other constins play a general role in horizontal gene transfer among gram-negative bacteria.

scholarly journals IS 1294 Reorganizes Plasmids in a Multidrug-Resistant Escherichia coli Strain

2021 ◽  
Author(s):  
Yushan Pan ◽  
Tengli Zhang ◽  
Lijie Yu ◽  
Zhiyong Zong ◽  
Shiyu Zhao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
16S Rrna ◽  
Multidrug Resistant ◽  
Coli Strain ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
16S Rrna Methylase

The increasing resistance to β-lactams and aminoglycoside antibiotics, mainly due to extended-spectrum β-lactamases (ESBLs) and 16S rRNA methylase genes, is becoming a serious problem in Gram-negative bacteria. Plasmids, as the vehicles for resistance gene capture and horizontal gene transfer, serve a key role in terms of antibiotic resistance emergence and transmission.

scholarly journals Incorporation of Plasmid DNA Into Bacterial Membrane Vesicles by Peptidoglycan Defects in Escherichia coli

2021 ◽  
Vol 12 ◽  
Author(s):  
Sharmin Aktar ◽  
Yuhi Okamoto ◽  
So Ueno ◽  
Yuhei O. Tahara ◽  
Masayoshi Imaizumi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Bacterial Membrane ◽  
Gram Negative Bacteria ◽  
Plasmid Copy ◽  
Gram Negative

Membrane vesicles (MVs) are released by various prokaryotes and play a role in the delivery of various cell-cell interaction factors. Recent studies have determined that these vesicles are capable of functioning as mediators of horizontal gene transfer. Outer membrane vesicles (OMVs) are a type of MV that is released by Gram-negative bacteria and primarily composed of outer membrane and periplasm components; however, it remains largely unknown why DNA is contained within OMVs. Our study aimed to understand the mechanism by which DNA that is localized in the cytoplasm is incorporated into OMVs in Gram-negative bacteria. We compared DNA associated with OMVs using Escherichia coli BW25113 cells harboring the non-conjugative, non-mobilized, and high-copy plasmid pUC19 and its hypervesiculating mutants that included ΔnlpI, ΔrseA, and ΔtolA. Plasmid copy per vesicle was increased in OMVs derived from ΔnlpI, in which peptidoglycan (PG) breakdown and synthesis are altered. When supplemented with 1% glycine to inhibit PG synthesis, both OMV formation and plasmid copy per vesicle were increased in the wild type. The bacterial membrane condition test indicated that membrane permeability was increased in the presence of glycine at the late exponential phase, in which cell lysis did not occur. Additionally, quick-freeze deep-etch and replica electron microscopy observations revealed that outer-inner membrane vesicles (O-IMVs) are formed in the presence of glycine. Thus, two proposed routes for DNA incorporation into OMVs under PG-damaged conditions are suggested. These routes include DNA leakage due to increased membrane permeation and O-IMV formation. Additionally, our findings contribute to a greater understanding of the vesicle-mediated horizontal gene transfer that occurs in nature and the utilization of MVs for DNA cargo.

scholarly journals Prey range and genome evolution ofHalobacteriovorax marinuspredatory bacteria from an estuary

2017 ◽  
Author(s):  
Brett G. Enos ◽  
Molly K. Anthony ◽  
Joseph A. DeGiorgis ◽  
Laura E. Williams
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Codon Usage ◽  
Genome Evolution ◽  
Genome Analysis ◽  
Regulation Of Gene Expression ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Predatory Bacteria ◽  
The Impact

AbstractBackgroundHalobacteriovoraxare saltwater-adapted predatory bacteria that attack Gram-negative bacteria and therefore may play an important role in shaping microbial communities. To understand the impact ofHalobacteriovoraxon ecosystems and develop them as biocontrol agents, it is important to characterize variation in predation phenotypes such as prey range and investigate the forces impactingHalobacteriovoraxgenome evolution across different phylogenetic distances.ResultsWe isolatedH. marinusBE01 from an estuary in Rhode Island usingVibriofrom the same site as prey. Small, fast-moving attack phase BE01 cells attach to and invade prey cells, consistent with the intraperiplasmic predation strategy ofH. marinustype strain SJ. BE01 is a prey generalist, forming plaques onVibriostrains from the estuary as well asPseudomonasfrom soil andE. coli. Genome analysis revealed that BE01 is very closely related to SJ, with extremely high conservation of gene order and amino acid sequences. Despite this similarity, we identified two regions of gene content difference that likely resulted from horizontal gene transfer. Analysis of modal codon usage frequencies supports the hypothesis that these regions were acquired from bacteria with different codon usage biases compared toHalobacteriovorax. In BE01, one of these regions includes genes associated with mobile genetic elements, such as a transposase not found in SJ and degraded remnants of an integrase occurring as a full-length gene in SJ. The corresponding region in SJ included unique mobile genetic element genes, such as a site-specific recombinase and bacteriophage-related genes not found in BE01. Acquired functions in BE01 include thedndoperon, which encodes a pathway for DNA modification that may protect DNA from nucleases, and a suite of genes involved in membrane synthesis and regulation of gene expression that was likely acquired from anotherHalobacteriovoraxlineage.ConclusionsOur results support previous observations thatHalobacteriovoraxprey on a broad range of Gram-negative bacteria. Genome analysis suggests strong selective pressure to maintain the genome in theH. marinuslineage represented by BE01 and SJ, although our results also provide further evidence that horizontal gene transfer plays an important role in genome evolution in predatory bacteria.

Mechanisms of DNA Uptake by Naturally Competent Bacteria

2019 ◽  
Vol 53 (1) ◽  
pp. 217-237 ◽  
Author(s):  
David Dubnau ◽  
Melanie Blokesch
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Outer Membrane ◽  
Growth Arrest ◽  
Dna Binding Protein ◽  
Gram Negative Bacteria ◽  
Dna Uptake ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Proton Symport

Transformation is a widespread mechanism of horizontal gene transfer in bacteria. DNA uptake to the periplasmic compartment requires a DNA-uptake pilus and the DNA-binding protein ComEA. In the gram-negative bacteria, DNA is first pulled toward the outer membrane by retraction of the pilus and then taken up by binding to periplasmic ComEA, acting as a Brownian ratchet to prevent backward diffusion. A similar mechanism probably operates in the gram-positive bacteria as well, but these systems have been less well characterized. Transport, defined as movement of a single strand of transforming DNA to the cytosol, requires the channel protein ComEC. Although less is understood about this process, it may be driven by proton symport. In this review we also describe various phenomena that are coordinated with the expression of competence for transformation, such as fratricide, the kin-discriminatory killing of neighboring cells, and competence-mediated growth arrest.

scholarly journals Gene Transfer Potential of Outer Membrane Vesicles of Gram-Negative Bacteria

2021 ◽  
Vol 22 (11) ◽  
pp. 5985
Author(s):  
Federica Dell’Annunziata ◽  
Veronica Folliero ◽  
Rosa Giugliano ◽  
Anna De Filippis ◽  
Cristina Santarcangelo ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Outer Membrane ◽  
Pathogenic Bacteria ◽  
Membrane Vesicles ◽  
Multidrug Resistant ◽  
Outer Membrane Vesicles ◽  
Biologically Active ◽  
Gram Negative Bacteria ◽  
Gram Negative

The increasing spread of multidrug-resistant pathogenic bacteria is one of the major threats to public health worldwide. Bacteria can acquire antibiotic resistance and virulence genes through horizontal gene transfer (HGT). A novel horizontal gene transfer mechanism mediated by outer membrane vesicles (OMVs) has been recently identified. OMVs are rounded nanostructures released during their growth by Gram-negative bacteria. Biologically active toxins and virulence factors are often entrapped within these vesicles that behave as molecular carriers. Recently, OMVs have been reported to contain DNA molecules, but little is known about the vesicle packaging, release, and transfer mechanisms. The present review highlights the role of OMVs in HGT processes in Gram-negative bacteria.

scholarly journals Spheres of Hope, Packets of Doom: the Good and Bad of Outer Membrane Vesicles in Interspecies and Ecological Dynamics

2017 ◽  
Vol 199 (15) ◽  
Author(s):  
Jonathan B. Lynch ◽  
Rosanna A. Alegado
Keyword(s):  
Antimicrobial Activity ◽  
Horizontal Gene Transfer ◽  
Outer Membrane ◽  
Recent Progress ◽  
Membrane Vesicles ◽  
Stress Relief ◽  
Outer Membrane Vesicles ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
By Products

ABSTRACT Outer membrane vesicles (OMVs) are proteoliposome nanoparticles ubiquitously produced by Gram-negative bacteria. Typically bearing a composition similar to those of the outer membrane and periplasm of the cells from which they are derived, OMVs package an array of proteins, lipids, and nucleic acids. Once considered inconsequential by-products of bacterial growth, OMVs have since been demonstrated to mediate cellular stress relief, promote horizontal gene transfer and antimicrobial activity, and elicit metazoan inflammation. Recently, OMVs have gained appreciation as critical moderators of interorganismal dynamics. In this review, we focus on recent progress toward understanding the functions of OMVs with regard to symbiosis and ecological contexts, and we propose potential avenues for future OMV studies.

The type VI secretion system ofVibrio choleraefosters horizontal gene transfer

Science ◽  
2015 ◽  
Vol 347 (6217) ◽  
pp. 63-67 ◽  
Author(s):  
Sandrine Borgeaud ◽  
Lisa C. Metzger ◽  
Tiziana Scrignari ◽  
Melanie Blokesch
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Positive Control ◽  
Secretion System ◽  
Type Vi Secretion System ◽  
Natural Competence ◽  
Type Vi Secretion ◽  
Encoding Gene

Natural competence for transformation is a common mode of horizontal gene transfer and contributes to bacterial evolution. Transformation occurs through the uptake of external DNA and its integration into the genome. Here we show that the type VI secretion system (T6SS), which serves as a predatory killing device, is part of the competence regulon in the naturally transformable pathogenVibrio cholerae. The T6SS-encoding gene cluster is under the positive control of the competence regulators TfoX and QstR and is induced by growth on chitinous surfaces. Live-cell imaging revealed that deliberate killing of nonimmune cells via competence-mediated induction of T6SS releases DNA and makes it accessible for horizontal gene transfer inV. cholerae.

Sign in / Sign up

Export Citation Format

Share Document