1
|
Liu G, Thomsen LE, Olsen JE. Antimicrobial-induced horizontal transfer of antimicrobial resistance genes in bacteria: a mini-review. J Antimicrob Chemother 2021; 77:556-567. [PMID: 34894259 DOI: 10.1093/jac/dkab450] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The emergence and spread of antimicrobial resistance (AMR) among pathogenic bacteria constitute an accelerating crisis for public health. The selective pressures caused by increased use and misuse of antimicrobials in medicine and livestock production have accelerated the overall selection of resistant bacteria. In addition, horizontal gene transfer (HGT) plays an important role in the spread of resistance genes, for example mobilizing reservoirs of AMR from commensal bacteria into pathogenic ones. Antimicrobials, besides antibacterial function, also result in undesirable effects in the microbial populations, including the stimulation of HGT. The main aim of this narrative review was to present an overview of the current knowledge of the impact of antimicrobials on HGT in bacteria, including the effects of transformation, transduction and conjugation, as well as other less well-studied mechanisms of HGT. It is widely accepted that conjugation plays a major role in the spread of AMR in bacteria, and the focus of this review is therefore mainly on the evidence provided that antimicrobial treatment affects this process. Other mechanisms of HGT have so far been deemed less important in this respect; however, recent discoveries suggest their role may be larger than previously thought, and the review provides an update on the rather limited knowledge currently available regarding the impact of antimicrobial treatment on these processes as well. A conclusion from the review is that there is an urgent need to investigate the mechanisms of antimicrobial-induced HGT, since this will be critical for developing new strategies to combat the spread of AMR.
Collapse
Affiliation(s)
- Gang Liu
- College of Veterinary Medicine, Qingdao Agricultural University, Qingdao 266109, China.,Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark
| | - Line Elnif Thomsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark
| | - John Elmerdahl Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 1870 Frederiksberg C, Denmark
| |
Collapse
|
2
|
Chen Z, Shen M, Mao C, Wang C, Yuan P, Wang T, Sun D. A Type I Restriction Modification System Influences Genomic Evolution Driven by Horizontal Gene Transfer in Paenibacillus polymyxa. Front Microbiol 2021; 12:709571. [PMID: 34413842 PMCID: PMC8370563 DOI: 10.3389/fmicb.2021.709571] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 06/29/2021] [Indexed: 11/13/2022] Open
Abstract
Considered a “Generally Recognized As Safe” (GRAS) bacterium, the plant growth–promoting rhizobacterium Paenibacillus polymyxa has been widely applied in agriculture and animal husbandry. It also produces valuable compounds that are used in medicine and industry. Our previous work showed the presence of restriction modification (RM) system in P. polymyxa ATCC 842. Here, we further analyzed its genome and methylome by using SMRT sequencing, which revealed the presence of a larger number of genes, as well as a plasmid documented as a genomic region in a previous report. A number of mobile genetic elements (MGEs), including 78 insertion sequences, six genomic islands, and six prophages, were identified in the genome. A putative lysozyme-encoding gene from prophage P6 was shown to express lysin which caused cell lysis. Analysis of the methylome and genome uncovered a pair of reverse-complementary DNA methylation motifs which were widespread in the genome, as well as genes potentially encoding their cognate type I restriction-modification system PpoAI. Further genetic analysis confirmed the function of PpoAI as a RM system in modifying and restricting DNA. The average frequency of the DNA methylation motifs in MGEs was lower than that in the genome, implicating a role of PpoAI in restricting MGEs during genomic evolution of P. polymyxa. Finally, comparative analysis of R, M, and S subunits of PpoAI showed that homologs of the PpoAI system were widely distributed in species belonging to other classes of Firmicute, implicating a role of the ancestor of PpoAI in the genomic evolution of species beyond Paenibacillus.
Collapse
Affiliation(s)
- Ziyan Chen
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Minjia Shen
- UMR 9198 Institut de Biologie Intégrative de la Cellule (I2BC), Gif-sur-Yvette, France
| | - Chengyao Mao
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Chenyu Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Panhong Yuan
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Tingzhang Wang
- Key Laboratory of Microbial Technology and Bioinformatics, Hangzhou, China
| | - Dongchang Sun
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| |
Collapse
|
3
|
Type IV-Like Pili Facilitate Transformation in Naturally Competent Archaea. J Bacteriol 2020; 202:JB.00355-20. [PMID: 32817089 DOI: 10.1128/jb.00355-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/07/2020] [Indexed: 12/19/2022] Open
Abstract
Naturally competent organisms are capable of DNA uptake directly from the environment through the process of transformation. Despite the importance of transformation to microbial evolution, DNA uptake remains poorly characterized outside of the bacterial domain. Here, we identify the pilus as a necessary component of the transformation machinery in archaea. We describe two naturally competent organisms, Methanococcus maripaludis and Methanoculleus thermophilus In M. maripaludis, replicative vectors were transferred with an average efficiency of 2.4 × 103 transformants μg-1 DNA. In M. thermophilus, integrative vectors were transferred with an average efficiency of 2.7 × 103 transformants μg-1 DNA. Additionally, natural transformation of M. thermophilus could be used to introduce chromosomal mutations. To our knowledge, this is the first demonstration of a method to introduce targeted mutations in a member of the order Methanomicrobiales For both organisms, mutants lacking structural components of the type IV-like pilus filament were defective for DNA uptake, demonstrating the importance of pili for natural transformation. Interestingly, competence could be induced in a noncompetent strain of M. maripaludis by expressing pilin genes from a replicative vector. These results expand the known natural competence pili to include examples from the archaeal domain and highlight the importance of pili for DNA uptake in diverse microbial organisms.IMPORTANCE Microbial organisms adapt and evolve by acquiring new genetic material through horizontal gene transfer. One way that this occurs is natural transformation, the direct uptake and genomic incorporation of environmental DNA by competent organisms. Archaea represent up to a third of the biodiversity on Earth, yet little is known about transformation in these organisms. Here, we provide the first characterization of a component of the archaeal DNA uptake machinery. We show that the type IV-like pilus is essential for natural transformation in two archaeal species. This suggests that pili are important for transformation across the tree of life and further expands our understanding of gene flow in archaea.
Collapse
|
4
|
Riva F, Riva V, Eckert EM, Colinas N, Di Cesare A, Borin S, Mapelli F, Crotti E. An Environmental Escherichia coli Strain Is Naturally Competent to Acquire Exogenous DNA. Front Microbiol 2020; 11:574301. [PMID: 33013812 PMCID: PMC7494812 DOI: 10.3389/fmicb.2020.574301] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 08/12/2020] [Indexed: 12/13/2022] Open
Abstract
The diffusion of antibiotic resistance determinants in different environments, e.g., soil and water, has become a public concern for global health and food safety and many efforts are currently devoted to clarify this complex ecological and evolutionary issue. Horizontal gene transfer (HGT) has an important role in the spread of antibiotic resistance genes (ARGs). However, among the different HGT mechanisms, the capacity of environmental bacteria to acquire naked exogenous DNA by natural competence is still poorly investigated. This study aimed to characterize the ability of the environmental Escherichia coli strain ED1, isolated from the crustacean Daphnia sp., to acquire exogenous DNA by natural competence. Transformation experiments were carried out varying different parameters, i.e., cell growth phase, amount of exogenous DNA and exposition to artificial lake water (ALW) and treated wastewater to mimic environmental-like conditions that may be encountered in the agri-food system. Results were compared with those showed by the laboratory E. coli strain DH5α. Our experimental data, supported by genomic sequencing, showed that, when exposed to pure water, ED1 strain was able to acquire exogenous DNA with frequencies (10–8–10–9) statistically higher than the ones observed for DH5α strain (10–10). Interestingly, higher values were retrieved for ED1 than DH5α strains exposed to ALW (10–7 vs. 10–9, respectively) or treated wastewater (10–8 vs. 10–10, respectively). We tested, therefore, ED1 strain ability to colonize the rhizosphere of lettuce, a model plant representative of raw-consumed vegetables of high economic importance in the ready-to-eat food industry. Results showed that ED1 strain was able to efficiently colonize lettuce rhizosphere, revealing a stable colonization for 14 days-long period. In conclusion, ED1 strain ability to acquire exogenous DNA in environmental-like conditions by natural competence, combined with its ability to efficiently and stably colonize plant rhizosphere, poses the attention to food and human safety showing a possible route of diffusion of antibiotic resistance in the agri-food system, sustaining the “One Health” warnings related to the antibiotic spread.
Collapse
Affiliation(s)
- Francesco Riva
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Milan, Italy
| | - Valentina Riva
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Milan, Italy
| | - Ester M Eckert
- Molecular Ecology Group, National Research Council - Water Research Institute (CNR-IRSA), Verbania, Italy
| | - Noemi Colinas
- Molecular Ecology Group, National Research Council - Water Research Institute (CNR-IRSA), Verbania, Italy.,Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Valencia, Spain
| | - Andrea Di Cesare
- Molecular Ecology Group, National Research Council - Water Research Institute (CNR-IRSA), Verbania, Italy
| | - Sara Borin
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Milan, Italy
| | - Francesca Mapelli
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Milan, Italy
| | - Elena Crotti
- Department of Food, Environmental and Nutritional Sciences (DeFENS), University of Milan, Milan, Italy
| |
Collapse
|
5
|
Histone-like Nucleoid-Structuring Protein (H-NS) Paralogue StpA Activates the Type I-E CRISPR-Cas System against Natural Transformation in Escherichia coli. Appl Environ Microbiol 2020; 86:AEM.00731-20. [PMID: 32385085 DOI: 10.1128/aem.00731-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 05/05/2020] [Indexed: 12/14/2022] Open
Abstract
Working mechanisms of CRISPR-Cas systems have been intensively studied. However, far less is known about how they are regulated. The histone-like nucleoid-structuring protein H-NS binds the promoter of cas genes (P cas ) and suppresses the type I-E CRISPR-Cas system in Escherichia coli Although the H-NS paralogue StpA also binds P cas , its role in regulating the CRISPR-Cas system remains unidentified. Our previous work established that E. coli is able to take up double-stranded DNA during natural transformation. Here, we investigated the function of StpA in regulating the type I-E CRISPR-Cas system against natural transformation of E. coli We first documented that although the activated type I-E CRISPR-Cas system, due to hns deletion, interfered with CRISPR-Cas-targeted plasmid transfer, stpA inactivation restored the level of natural transformation. Second, we showed that inactivating stpA reduced the transcriptional activity of P cas Third, by comparing transcriptional activities of the intact P cas and the P cas with a disrupted H-NS binding site in the hns and hns stpA null deletion mutants, we demonstrated that StpA activated transcription of cas genes by binding to the same site as H-NS in P cas Fourth, by expressing StpA with an arabinose-inducible promoter, we confirmed that StpA expressed at a low level stimulated the activity of P cas Finally, by quantifying the level of mature CRISPR RNA (crRNA), we demonstrated that StpA was able to promote the amount of crRNA. Taken together, our work establishes that StpA serves as a transcriptional activator in regulating the type I-E CRISPR-Cas system against natural transformation of E. coli IMPORTANCE StpA is normally considered a molecular backup of the nucleoid-structuring protein H-NS, which was reported as a transcriptional repressor of the type I-E CRISPR-Cas system in Escherichia coli However, the role of StpA in regulating the type I-E CRISPR-Cas system remains elusive. Our previous work uncovered a new route for double-stranded DNA (dsDNA) entry during natural transformation of E. coli In this study, we show that StpA plays a role opposite to that of its paralogue H-NS in regulating the type I-E CRISPR-Cas system against natural transformation of E. coli Our work not only expands our knowledge on CRISPR-Cas-mediated adaptive immunity against extracellular nucleic acids but also sheds new light on understanding the complex regulation mechanism of the CRISPR-Cas system. Moreover, the finding that paralogues StpA and H-NS share a DNA binding site but play opposite roles in transcriptional regulation indicates that higher-order compaction of bacterial chromatin by histone-like proteins could switch prokaryotic transcriptional modes.
Collapse
|
6
|
Chemical transformation mediated CRISPR/Cas9 genome editing in Escherichia coli. Biotechnol Lett 2018; 41:293-303. [PMID: 30547274 DOI: 10.1007/s10529-018-02639-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 12/08/2018] [Indexed: 10/27/2022]
Abstract
OBJECTIVES To develop a convenient chemical transformation mediated CRISPR/Cas9 (CT-CRISPR/Cas9) system for genome editing in Escherichia coli. RESULTS Here, we have constructed a CT-CRISPR/Cas9 system, which can precisely edit bacterial genome (replacing, deleting, inserting or point mutating a target gene) through chemical transformation. Compared with the traditional electroporation mediated CRISPR/Cas9 (ET-CRISPR/Cas9) system, genome editing with the CT-CRISPR/Cas9 system is much cheaper and simpler. In the CT-CRISPR/Cas9 system, we observed efficient genome editing on LB-agar plates. The CT-CRISPR/Cas9 system has successfully modified the target gene with the editing template flanked by short homologous DNA fragments (~ 50 bp) which were designed in primers. We used the lab-made CaCl2 solution to perform the CT-CRISPR/Cas9 experiment and successfully edited the genome of E. coli. Potential application of the CT-CRISPR/Cas9 system in high-throughput genome editing was evaluated in two E. coli strains by using a multiwell plate. CONCLUSIONS Our work provides a simple and cheap genome-editing method, that is expected to be widely applied as a routine genetic engineering method.
Collapse
|
7
|
Hasegawa H, Suzuki E, Maeda S. Horizontal Plasmid Transfer by Transformation in Escherichia coli: Environmental Factors and Possible Mechanisms. Front Microbiol 2018; 9:2365. [PMID: 30337917 PMCID: PMC6180151 DOI: 10.3389/fmicb.2018.02365] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 09/14/2018] [Indexed: 12/16/2022] Open
Abstract
Transformation is one mode of horizontal gene transfer (HGT) in bacteria, wherein extracellular naked DNA is taken up by cells that have developed genetic competence. Sensitivity to DNase, which degrades naked DNA, is the key to distinguishing transformation from the DNase-resistant HGT mechanisms. In general, Escherichia coli is not believed to be naturally transformable; it develops high competence only under artificial conditions, including exposure to high Ca2+ concentrations. However, E. coli can reportedly express modest competence under certain conditions that are feasible in natural environments outside laboratory. In addition, recent data suggest that environmental factors influence multiple routes of transformation. In this mini review, we (1) summarize our studies on transformation-based HGT using E. coli experimental systems and (2) discuss the possible occurrence of transformation via multiple mechanisms in the environment and its possible impact on the spread of antibiotic resistance genes.
Collapse
Affiliation(s)
| | | | - Sumio Maeda
- Graduate School of Humanities and Sciences, Nara Women’s University, Nara, Japan
| |
Collapse
|
8
|
Sun D. Pull in and Push Out: Mechanisms of Horizontal Gene Transfer in Bacteria. Front Microbiol 2018; 9:2154. [PMID: 30237794 PMCID: PMC6135910 DOI: 10.3389/fmicb.2018.02154] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 08/22/2018] [Indexed: 01/06/2023] Open
Abstract
Horizontal gene transfer (HGT) plays an important role in bacterial evolution. It is well accepted that DNA is pulled/pushed into recipient cells by conserved membrane-associated DNA transport systems, which allow the entry of only single-stranded DNA (ssDNA). However, recent studies have uncovered a new type of natural bacterial transformation in which double-stranded DNA (dsDNA) is taken up into the cytoplasm, thus complementing the existing methods of DNA transfer among bacteria. Regulated by the stationary-phase regulators RpoS and cAMP receptor protein (CRP), Escherichia coli establishes competence for natural transformation with dsDNA, which occurs in agar plates. To pass across the outer membrane, a putative channel, which may compete for the substrate with the porin OmpA, may mediate the transfer of exogenous dsDNA into the cell. To pass across the inner membrane, dsDNA may be bound to the periplasmic protein YdcS, which delivers it into the inner membrane channel formed by YdcV. The discovery of cell-to-cell contact-dependent plasmid transformation implies the presence of additional mechanism(s) of transformation. This review will summarize the current knowledge about mechanisms of HGT with an emphasis on recent progresses regarding non-canonical mechanisms of natural transformation. Fully understanding the mechanisms of HGT will provide a foundation for monitoring and controlling multidrug resistance.
Collapse
Affiliation(s)
- Dongchang Sun
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| |
Collapse
|
9
|
Tokar T, Pastrello C, Ramnarine VR, Zhu CQ, Craddock KJ, Pikor LA, Vucic EA, Vary S, Shepherd FA, Tsao MS, Lam WL, Jurisica I. Differentially expressed microRNAs in lung adenocarcinoma invert effects of copy number aberrations of prognostic genes. Oncotarget 2018; 9:9137-9155. [PMID: 29507679 PMCID: PMC5823624 DOI: 10.18632/oncotarget.24070] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 01/02/2018] [Indexed: 12/30/2022] Open
Abstract
In many cancers, significantly down- or upregulated genes are found within chromosomal regions with DNA copy number alteration opposite to the expression changes. Generally, this paradox has been overlooked as noise, but can potentially be a consequence of interference of epigenetic regulatory mechanisms, including microRNA-mediated control of mRNA levels. To explore potential associations between microRNAs and paradoxes in non-small-cell lung cancer (NSCLC) we curated and analyzed lung adenocarcinoma (LUAD) data, comprising gene expressions, copy number aberrations (CNAs) and microRNA expressions. We integrated data from 1,062 tumor samples and 241 normal lung samples, including newly-generated array comparative genomic hybridization (aCGH) data from 63 LUAD samples. We identified 85 “paradoxical” genes whose differential expression consistently contrasted with aberrations of their copy numbers. Paradoxical status of 70 out of 85 genes was validated on sample-wise basis using The Cancer Genome Atlas (TCGA) LUAD data. Of these, 41 genes are prognostic and form a clinically relevant signature, which we validated on three independent datasets. By meta-analysis of results from 9 LUAD microRNA expression studies we identified 24 consistently-deregulated microRNAs. Using TCGA-LUAD data we showed that deregulation of 19 of these microRNAs explains differential expression of the paradoxical genes. Our results show that deregulation of paradoxical genes is crucial in LUAD and their expression pattern is maintained epigenetically, defying gene copy number status.
Collapse
Affiliation(s)
- Tomas Tokar
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Chiara Pastrello
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Varune R Ramnarine
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.,The Vancouver Prostate Centre, Vancouver General Hospital, Vancouver, Canada
| | - Chang-Qi Zhu
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Kenneth J Craddock
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Larrisa A Pikor
- Department of Integrative Oncology, British Columbia Cancer Research Centre, Vancouver, Canada
| | - Emily A Vucic
- Department of Integrative Oncology, British Columbia Cancer Research Centre, Vancouver, Canada
| | - Simon Vary
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.,Mathematical Institute, University of Oxford, Oxford, United Kingdom.,Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, Slovakia
| | - Frances A Shepherd
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
| | - Ming-Sound Tsao
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | - Wan L Lam
- Department of Integrative Oncology, British Columbia Cancer Research Centre, Vancouver, Canada
| | - Igor Jurisica
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Department of Computer Science, University of Toronto, Toronto, Canada.,Institute of Neuroimmunology, Slovak Academy of Sciences, Bratislava, Slovakia
| |
Collapse
|