scholarly journals Conjugative transfer of naturally occurring plasmids in Mycolicibacterium sp.

2021 ◽  
Author(s):  
Sergio Morgado ◽  
Ana Carolina Vicente
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Natural Environment ◽  
Model Organism ◽  
Conjugative Transfer ◽  
Bacterial Adaptation ◽  
Naturally Occurring ◽  
Conjugation Process

Conjugation is considered the main horizontal gene transfer (HGT) mechanism in bacterial adaptation and evolution. In the Mycobacteriaceae family, Mycolicibacterium smegmatis has been used as the model organism for the conjugative transfer of hybrid plasmids. However, the natural conjugation process in any bacteria would involve the transfer of naturally occurring plasmids. Currently, there is a gap in this regard in relation to this abundant environmental genus of Mycobacteriaceae. Here, we performed conjugation experiments between wild Mycolicibacterium sp. strains involving naturally occurring plasmids (sizes of 21 and 274 kb), and interestingly, evidence of conjugative transfer was obtained. Thus, it is likely that conjugation occurs in Mycolicibacterium in the natural environment, representing a source of diversification and evolution in this genus of bacteria.

Genomic Analysis of Citrobacter Portucalensis Sb-2 Identifies a Phage Predation Driven Metalloid Resistance

2021 ◽  
Author(s):  
Yanshuang Yu ◽  
Zhenchen Xie ◽  
Jigang Yang ◽  
Jinxuan Liang ◽  
YuanPing Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Significant Role ◽  
Genome Analysis ◽  
Extreme Environments ◽  
Genomic Analysis ◽  
Resistant Bacterium ◽  
Bacterial Adaptation ◽  
Resistance Determinants

Abstract Bacterial adaptation to extreme environments is often mediated by horizontal gene transfer (HGT). At the same time, phage mediated HGT for conferring bacterial arsenite and antimonite resistance has not been documented before. In this study, a highly arsenite and antimonite resistant bacterium, C. portucalensis strain Sb-2, was isolated and subsequent genome analysis showed that putative arsenite and antimonite resistance determinants were flanked or embedded by prophages. We predict these phage-mediated resistances play a significant role in maintaining genetic diversity within the genus of Citrobacter and are responsible for endowing the corresponding resistances to C. portucalensis strain Sb-2.

scholarly journals Horizontal Gene Transfer from Genus Agrobacterium to the Plant Linaria in Nature

2012 ◽  
Vol 25 (12) ◽  
pp. 1542-1551 ◽  
Author(s):  
Tatiana V. Matveeva ◽  
Denis I. Bogomaz ◽  
Olga A. Pavlova ◽  
Eugene W. Nester ◽  
Ludmila A. Lutova
Keyword(s):  
Polymerase Chain Reaction ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Dna Sequence ◽  
Plant Species ◽  
Natural Environment ◽  
Direct Repeat ◽  
Chain Reaction ◽  
Homologous Sequences ◽  
Polymerase Chain

Genes can be transferred horizontally between prokaryotes and eukaryotes in nature. The best-studied examples occur between Agrobacterium rhizogenes and certain Nicotiana spp. To investigate possible additional cases of horizontal gene transfer in nature between Agrobacterium and plants, a real-time polymerase chain reaction-based approach was employed to screen 127 plant species, belonging to 38 families of Dicotyledones, for the presence of oncogenes homologous to the transfer DNA fragments (T-DNA) from both A. tumefaciens and A. rhizogenes. Among all of the analyzed plant species, we found that only Linaria vulgaris contained sequences homologous to the T-DNA of A. rhizogenes. All screened L. vulgaris plants from various parts of Russia contained the same homologous sequences, including rolB, rolC, ORF13, ORF14, and mis genes. The same opine gene is found in the species of Nicotiana which contain genes of A. rhizogenes. In L. vulgaris, there are two copies of T-DNA organized as a single tandem imperfect direct repeat. The plant DNA sequence of the site of integration shows similarity to a retrotransposon. This site is most likely silent, suggesting that the T-DNA is not expressed. Attempts to demonstrate expression of the T-DNA genes were negative. Our study indicates that the frequency of gene transfer and fixation in the germline from Agrobacterium to plant hosts is rare in the natural environment.

scholarly journals The Prophages ofCitrobacter rodentiumRepresent a Conserved Family of Horizontally Acquired Mobile Genetic Elements Associated with Enteric Evolution towards Pathogenicity

2019 ◽  
Vol 201 (9) ◽  
Author(s):  
Samuel J. Magaziner ◽  
Ziyue Zeng ◽  
Bihe Chen ◽  
George P. C. Salmond
Keyword(s):  
Phylogenetic Analysis ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Virulence Factors ◽  
Model Organism ◽  
Temperate Phage ◽  
Enteric Bacterium ◽  
Citrobacter Rodentium ◽  
Content Type ◽  
Intestinal Pathogens

ABSTRACTProphage-mediated horizontal gene transfer (HGT) plays a key role in the evolution of bacteria, enabling access to new environmental niches, including pathogenicity.Citrobacter rodentiumis a host-adapted intestinal mouse pathogen and important model organism for attaching and effacing (A/E) pathogens, including the clinically significant enterohaemorrhagic and enteropathogenicEscherichia coli(EHEC and EPEC, respectively). Even thoughC. rodentiumcontains 10 prophage genomic regions, including an active temperate phage, ΦNP, little was known regarding the nature ofC. rodentiumprophages in the bacterium’s evolution toward pathogenicity. In this study, our characterization of ΦNP led to the discovery of a second, fully functional temperate phage, named ΦSM. We identify the bacterial host receptor for both phages as lipopolysaccharide (LPS). ΦNP and ΦSM are likely important mediators of HGT inC. rodentium. Bioinformatic analysis of the 10 prophage regions reveals cargo genes encoding known virulence factors, including several type III secretion system (T3SS) effectors.C. rodentiumprophages are conserved across a wide range of pathogenic enteric bacteria, including EPEC and EHEC as well as pathogenic strains ofSalmonella enterica,Shigella boydii, andKlebsiella pneumoniae. Phylogenetic analysis of core enteric backbone genes compared against prophage evolutionary models suggests that these prophages represent an important, conserved family of horizontally acquired enteric-bacterium-associated pathogenicity determinants. In addition to highlighting the transformative role of bacteriophage-mediated HGT inC. rodentium’s evolution toward pathogenicity, these data suggest that the examination of conserved families of prophages in other pathogenic bacteria and disease outbreaks might provide deeper evolutionary and pathological insights otherwise obscured by more classical analysis.IMPORTANCEBacteriophages are obligate intracellular parasites of bacteria. Some bacteriophages can confer novel bacterial phenotypes, including pathogenicity, through horizontal gene transfer (HGT). The pathogenic bacteriumCitrobacter rodentiuminfects mice using mechanisms similar to those employed by human gastrointestinal pathogens, making it an important model organism. Here, we examined the 10 prophages ofC. rodentium, investigating their roles in its evolution toward virulence. We characterized ΦNP and ΦSM, two endogenous active temperate bacteriophages likely important for HGT. We showed that the 10 prophages encode predicted virulence factors and are conserved within other intestinal pathogens. Phylogenetic analysis suggested that they represent a conserved family of horizontally acquired enteric-bacterium-associated pathogenic determinants. Consequently, similar analysis of prophage elements in other pathogens might further understanding of their evolution and pathology.

A naturally occurring horizontal gene transfer from a eukaryote to a prokaryote

1990 ◽  
Vol 31 (5) ◽  
pp. 383-388 ◽  
Author(s):  
R. F. Doolittle ◽  
D. F. Feng ◽  
K. L. Anderson ◽  
M. R. Alberro
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Naturally Occurring

scholarly journals Role of Vibrio cholerae exochitinase ChiA2 in horizontal gene transfer

2016 ◽  
Vol 62 (3) ◽  
pp. 201-209 ◽  
Author(s):  
Moumita Mondal ◽  
Nabendu Sekhar Chatterjee
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Vibrio Cholerae ◽  
Natural Environment ◽  
Environmental Conditions ◽  
High Performance ◽  
Environmental Condition ◽  
Chromatography Analysis ◽  
Chitin Hydrolysis ◽  
Favorable Environmental Condition

Vibrio cholerae exochitinase ChiA2 plays a key role in acquisition of nutrients by chitin hydrolysis in the natural environment as well as in pathogenesis in the intestinal milieu. In this study we demonstrate the importance of ChiA2 in horizontal gene transfer in the natural environment. We found that the expression of ChiA2 and TfoX, the central regulator of V. cholerae horizontal gene transfer, varied with changes in environmental conditions. The activity of ChiA2 was also dependent on these conditions. In 3 different environmental conditions tested here, we observed that the supporting environmental condition for maximum expression and activity of ChiA2 was 20 °C, pH 5.5, and 100 mmol/L salinity in the presence of chitin. The same condition also induced TfoX expression and was favorable for horizontal gene transfer in V. cholerae. High-performance liquid chromatography analysis showed that ChiA2 released a significant amount of (GlcNAc)2 from chitin hydrolysis under the favorable condition. We hypothesized that under the favorable environmental condition, ChiA2 was upregulated and maximally active to produce a significant amount of (GlcNAc)2 from chitin. The same environmental condition also induced tfoX expression, followed by its translational activation by the (GlcNAc)2 produced, leading to efficient horizontal gene transfer.

Naturally occurring horizontal gene transfer and homologous recombination in Mycobacterium

Microbiology ◽  
2004 ◽  
Vol 150 (6) ◽  
pp. 1707-1712 ◽  
Author(s):  
Elzbieta Krzywinska ◽  
Jaroslaw Krzywinski ◽  
Jeffrey S. Schorey
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Homologous Recombination ◽  
Mycobacterium Avium ◽  
Pathogenic Bacteria ◽  
Evolutionary Process ◽  
Likelihood Estimation ◽  
Human Pathogens ◽  
Naturally Occurring ◽  
Genes Encoding

Acquisition of genetic information through horizontal gene transfer (HGT) is an important evolutionary process by which micro-organisms gain novel phenotypic characteristics. In pathogenic bacteria, for example, it facilitates maintenance and enhancement of virulence and spread of drug resistance. In the genus Mycobacterium, to which several primary human pathogens belong, HGT has not been clearly demonstrated. The few existing reports suggesting this process are based on circumstantial evidence of similarity of sequences found in distantly related species. Here, direct evidence of HGT between strains of Mycobacterium avium representing two different serotypes is presented. Conflicting evolutionary histories of genes encoding elements of the glycopeptidolipid (GPL) biosynthesis pathway led to an analysis of the GPL cluster genomic sequences from four Mycobacterium avium strains. The sequence of M. avium strain 2151 appeared to be a mosaic consisting of three regions having alternating identities to either M. avium strains 724 or 104. Maximum-likelihood estimation of two breakpoints allowed a ∼4100 bp region horizontally transferred into the strain 2151 genome to be pinpointed with confidence. The maintenance of sequence continuity at both breakpoints and the lack of insertional elements at these sites strongly suggest that the integration of foreign DNA occurred by homologous recombination. To our knowledge, this is the first report to demonstrate naturally occurring homologous recombination in Mycobacterium. This previously undiscovered mechanism of genetic exchange may have major implications for the understanding of Mycobacterium pathogenesis.

scholarly journals Biofilm Formation Drives Transfer of the Conjugative Element ICEBs1inBacillus subtilis

mSphere ◽  
2018 ◽  
Vol 3 (5) ◽  
Author(s):  
Frédéric Lécuyer ◽  
Jean-Sébastien Bourassa ◽  
Martin Gélinas ◽  
Vincent Charron-Lamoureux ◽  
Vincent Burrus ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Antibiotic Resistance ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
High Rate ◽  
Conjugative Transfer ◽  
Bacterial Strains ◽  
Content Type

ABSTRACTHorizontal gene transfer by integrative and conjugative elements (ICEs) is a very important mechanism for spreading antibiotic resistance in various bacterial species. In environmental and clinical settings, most bacteria form biofilms as a way to protect themselves against extracellular stress. However, much remains to be known about ICE transfer in biofilms. Using ICEBs1fromBacillus subtilis, we show that the natural conjugation efficiency of this ICE is greatly affected by the ability of the donor and recipient to form a biofilm. ICEBs1transfer considerably increases in biofilm, even at low donor/recipient ratios. Also, while there is a clear temporal correlation between biofilm formation and ICEBs1transfer, biofilms do not alter the level of ICEBs1excision in donor cells. Conjugative transfer appears to be favored by the biophysical context of biofilms. Indeed, extracellular matrix production, particularly from the recipient cells, is essential for biofilms to promote ICEBs1transfer. Our study provides basic new knowledge on the high rate of conjugative transfer of ICEs in biofilms, a widely preponderant bacterial lifestyle in the environment, which could have a major impact on our understanding of horizontal gene transfer in natural and clinical environments.IMPORTANCETransfer of mobile genetic elements from one bacterium to another is the principal cause of the spread of antibiotic resistance. However, the dissemination of these elements in environmental contexts is poorly understood. In clinical and environmental settings, bacteria are often found living in multicellular communities encased in a matrix, a structure known as a biofilm. In this study, we examined how forming a biofilm influences the transmission of an integrative and conjugative element (ICE). Using the model Gram-positive bacteriumB. subtilis, we observed that biofilm formation highly favors ICE transfer. This increase in conjugative transfer is due to the production of extracellular matrix, which creates an ideal biophysical context. Our study provides important insights into the role of the biofilm structure in driving conjugative transfer, which is of major importance since biofilm is a widely preponderant bacterial lifestyle for clinically relevant bacterial strains.

scholarly journals Stringent and Relaxed Recognition of oriT by Related Systems for Plasmid Mobilization: Implications for Horizontal Gene Transfer

2006 ◽  
Vol 188 (2) ◽  
pp. 499-506 ◽  
Author(s):  
Sarah Jandle ◽  
Richard Meyer
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Inverted Repeat ◽  
Base Sequence ◽  
Conjugative Transfer ◽  
Base Pairs ◽  
The Core ◽  
Plasmid Mobilization ◽  
Necessary And Sufficient ◽  
Conserved Core

ABSTRACT The plasmids R1162 and pSC101 have origins of conjugative transfer (oriTs) and corresponding relaxases that are closely related. The oriTs are made up of a highly conserved core, where DNA is cleaved by the relaxase prior to transfer, and an inverted repeat that differs in size and sequence. We show that in each case the seven base pairs adjacent to the core and within one arm of the inverted repeat are sufficient to determine specificity. Within this DNA there are three AT base pairs located 4 bp from the core. Mutations in the AT base pairs suggest that the relaxase makes essential contacts at these locations to the minor groove of the DNA. The remaining four bases are different for each oriT and are both necessary and sufficient for stringent recognition of oriT by the pSC101 mobilization proteins. In contrast, the R1162 mobilization proteins have a much more relaxed requirement for the base sequence of this specificity region. As a result, the R1162 mobilization proteins can initiate transfer from a variety of sites, including those derived from the chromosome. The R1162 mobilization proteins could therefore contribute to the horizontal gene transfer of DNA from diverse sources.

scholarly journals A bistable orthogonal prokaryotic differentiation system underlying development of conjugative transfer competence

2021 ◽  
Author(s):  
Sandra Sulser ◽  
Andrea Vucicevic ◽  
Veronica Bellini ◽  
Roxane Moritz ◽  
Francois Delavat ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Life Style ◽  
Mobile Elements ◽  
Conjugative Transfer ◽  
Transfer Processes ◽  
Gene Functions ◽  
Xenobiotic Compound ◽  
Efficient Transfer ◽  
Integrative And Conjugative Element

The mechanisms and impact of horizontal gene transfer processes to distribute gene functions with potential adaptive benefit among prokaryotes have been well documented. In contrast, little is known about the life-style of mobile elements mediating horizontal gene transfer, whereas this is the ultimate determinant for their transfer fitness. Here, we investigate the life-style of an integrative and conjugative element (ICE) within the genus Pseudomonas that stands model for a widespread family transmitting genes for xenobiotic compound metabolism and antibiotic resistances. The ICE only transfers from a small fraction of cells in a population, which we uncover here, results from a dedicated transfer competence program imposed by the ICE. Transfer competence is orthogonally maintained in individual cells in which it is activated, making them the centerpiece of ICE conjugation. The components mediating transfer competence are widely conserved, underscoring their selected fitness for efficient transfer of this class of mobile elements.

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