1
|
Cooper RM, Wright JA, Ng JQ, Goyne JM, Suzuki N, Lee YK, Ichinose M, Radford G, Ryan FJ, Kumar S, Thomas EM, Vrbanac L, Knight R, Woods SL, Worthley DL, Hasty J. Engineered bacteria detect tumor DNA. Science 2023; 381:682-686. [PMID: 37561843 PMCID: PMC10852993 DOI: 10.1126/science.adf3974] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 06/21/2023] [Indexed: 08/12/2023]
Abstract
Synthetic biology has developed sophisticated cellular biosensors to detect and respond to human disease. However, biosensors have not yet been engineered to detect specific extracellular DNA sequences and mutations. Here, we engineered naturally competent Acinetobacter baylyi to detect donor DNA from the genomes of colorectal cancer (CRC) cells, organoids, and tumors. We characterized the functionality of the biosensors in vitro with coculture assays and then validated them in vivo with sensor bacteria delivered to mice harboring colorectal tumors. We observed horizontal gene transfer from the tumor to the sensor bacteria in our mouse model of CRC. This cellular assay for targeted, CRISPR-discriminated horizontal gene transfer (CATCH) enables the biodetection of specific cell-free DNA.
Collapse
Affiliation(s)
- Robert M. Cooper
- Synthetic Biology Institute, University of California, San Diego, La Jolla, CA, USA, 92093
| | - Josephine A. Wright
- Precision Cancer Medicine Theme, South Australia Health and Medical Research Institute, Adelaide, SA, Australia, 5000
| | - Jia Q. Ng
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia, 5000
| | - Jarrad M. Goyne
- Precision Cancer Medicine Theme, South Australia Health and Medical Research Institute, Adelaide, SA, Australia, 5000
| | - Nobumi Suzuki
- Precision Cancer Medicine Theme, South Australia Health and Medical Research Institute, Adelaide, SA, Australia, 5000
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia, 5000
| | - Young K. Lee
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia, 5000
| | - Mari Ichinose
- Precision Cancer Medicine Theme, South Australia Health and Medical Research Institute, Adelaide, SA, Australia, 5000
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia, 5000
| | - Georgette Radford
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia, 5000
| | - Feargal J. Ryan
- Precision Cancer Medicine Theme, South Australia Health and Medical Research Institute, Adelaide, SA, Australia, 5000
- Flinders Health and Medical Research Institute, Flinders University, Bedford Park, SA, Australia, 5042
| | - Shalni Kumar
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, 92093
| | - Elaine M. Thomas
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia, 5000
| | - Laura Vrbanac
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia, 5000
| | - Rob Knight
- Molecular Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA, 92093
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, 92093
- Department of Computer Science & Engineering, University of California, San Diego, La Jolla, CA, 92093
- Center for Microbiome Innovation, University of California, San Diego, La Jolla, CA, 92093
| | - Susan L. Woods
- Precision Cancer Medicine Theme, South Australia Health and Medical Research Institute, Adelaide, SA, Australia, 5000
- Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia, 5000
| | - Daniel L. Worthley
- Precision Cancer Medicine Theme, South Australia Health and Medical Research Institute, Adelaide, SA, Australia, 5000
- Colonoscopy Clinic, Brisbane, QLD, Australia, 4000
| | - Jeff Hasty
- Synthetic Biology Institute, University of California, San Diego, La Jolla, CA, USA, 92093
- Department of Bioengineering, University of California, San Diego, La Jolla, CA, 92093
- Molecular Biology Section, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA, 92093
- Center for Microbiome Innovation, University of California, San Diego, La Jolla, CA, 92093
| |
Collapse
|
2
|
Calderón-Franco D, van Loosdrecht MCM, Abeel T, Weissbrodt DG. Catch me if you can: capturing microbial community transformation by extracellular DNA using Hi-C sequencing. Antonie Van Leeuwenhoek 2023:10.1007/s10482-023-01834-z. [PMID: 37156983 DOI: 10.1007/s10482-023-01834-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 04/24/2023] [Indexed: 05/10/2023]
Abstract
The transformation of environmental microorganisms by extracellular DNA is an overlooked mechanism of horizontal gene transfer and evolution. It initiates the acquisition of exogenous genes and propagates antimicrobial resistance alongside vertical and conjugative transfers. We combined mixed-culture biotechnology and Hi-C sequencing to elucidate the transformation of wastewater microorganisms with a synthetic plasmid encoding GFP and kanamycin resistance genes, in the mixed culture of chemostats exposed to kanamycin at concentrations representing wastewater, gut and polluted environments (0.01-2.5-50-100 mg L-1). We found that the phylogenetically distant Gram-negative Runella (102 Hi-C links), Bosea (35), Gemmobacter (33) and Zoogloea (24) spp., and Gram-positive Microbacterium sp. (90) were transformed by the foreign plasmid, under high antibiotic exposure (50 mg L-1). In addition, the antibiotic pressure shifted the origin of aminoglycoside resistance genes from genomic DNA to mobile genetic elements on plasmids accumulating in microorganisms. These results reveal the power of Hi-C sequencing to catch and surveil the transfer of xenogenetic elements inside microbiomes.
Collapse
Affiliation(s)
| | | | - Thomas Abeel
- Delft Bioinformatics Lab, Delft University of Technology, Delft, The Netherlands
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - David G Weissbrodt
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology, Trondheim, Norway.
| |
Collapse
|
3
|
Moralez J, Szenkiel K, Hamilton K, Pruden A, Lopatkin AJ. Quantitative analysis of horizontal gene transfer in complex systems. Curr Opin Microbiol 2021; 62:103-109. [PMID: 34098510 DOI: 10.1016/j.mib.2021.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 04/29/2021] [Accepted: 05/01/2021] [Indexed: 11/24/2022]
Abstract
Horizontal gene transfer (HGT) plays a significant role in rapidly propagating diverse traits throughout bacterial populations, thereby accelerating natural evolution and leading to complex community structures. Critical gene transfer rates underlying these occurrences dictate the efficiency and speed of gene spread; these rates are often highly specific to HGT mechanism and environmental context, and have historically been challenging to reliably quantify. In this review, we examine recent works that leverage rigorous quantitative methods to precisely measure these rates in a variety of settings beginning with in vitro studies and advancing to in situ measurements; we emphasize contexts where quantification across multiple scales of complexity has led to fundamental biological insights. Finally, we highlight the applications of these measurements and suggest potential methodological advances to improve our understanding.
Collapse
Affiliation(s)
- Jenifer Moralez
- Department of Biology, Barnard College, New York, NY 10027, USA
| | | | - Kerry Hamilton
- School of Sustainable Engineering and the Built Environment, 660 S College Ave, Tempe AZ 85281, USA; The Biodesign Center for Environmental Health Engineering, 1001 S McAllister Ave, Tempe AZ 85287, USA
| | - Amy Pruden
- Virginia Tech, Department of Civil & Environmental Engineering, Blacksburg, VA 24060, USA
| | - Allison J Lopatkin
- Department of Biology, Barnard College, New York, NY 10027, USA; Department Ecology, Evolution, and Environmental Biology, Columbia University, New York, NY 10027, USA; Data Science Institute, Columbia University, New York, NY 10027, USA.
| |
Collapse
|
4
|
de Santis B, Stockhofe N, Wal JM, Weesendorp E, Lallès JP, van Dijk J, Kok E, De Giacomo M, Einspanier R, Onori R, Brera C, Bikker P, van der Meulen J, Kleter G. Case studies on genetically modified organisms (GMOs): Potential risk scenarios and associated health indicators. Food Chem Toxicol 2018; 117:36-65. [DOI: 10.1016/j.fct.2017.08.033] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 07/03/2017] [Accepted: 08/22/2017] [Indexed: 01/07/2023]
|
5
|
Reusing Treated Wastewater: Consideration of the Safety Aspects Associated with Antibiotic-Resistant Bacteria and Antibiotic Resistance Genes. WATER 2018. [DOI: 10.3390/w10030244] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
6
|
Delaney B, Goodman RE, Ladics GS. Food and Feed Safety of Genetically Engineered Food Crops. Toxicol Sci 2017; 162:361-371. [DOI: 10.1093/toxsci/kfx249] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Bryan Delaney
- DuPont Pioneer, International, Inc, 8325 N 62nd Avenue, Johnston, IA 50131, USA
| | - Richard E Goodman
- Food Science & Technology, University of Nebraska, 1901 North 21St Street, Lincoln Nebraska, Lincoln, NE 68588, USA
| | - Gregory S Ladics
- DuPont Haskell Laboratory, 1090 Elkton Road, Newark, DE, 19711, USA
| |
Collapse
|
7
|
Cooper RM, Tsimring L, Hasty J. Inter-species population dynamics enhance microbial horizontal gene transfer and spread of antibiotic resistance. eLife 2017; 6:e25950. [PMID: 29091031 PMCID: PMC5701796 DOI: 10.7554/elife.25950] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 10/10/2017] [Indexed: 01/13/2023] Open
Abstract
Horizontal gene transfer (HGT) plays a major role in the spread of antibiotic resistance. Of particular concern are Acinetobacter baumannii bacteria, which recently emerged as global pathogens, with nosocomial mortality rates reaching 19-54% (Centers for Disease Control and Prevention, 2013; Joly Guillou, 2005; Talbot et al., 2006). Acinetobacter gains antibiotic resistance remarkably rapidly (Antunes et al., 2014; Joly Guillou, 2005), with multi drug-resistance (MDR) rates exceeding 60% (Antunes et al., 2014; Centers for Disease Control and Prevention, 2013). Despite growing concern (Centers for Disease Control and Prevention, 2013; Talbot et al., 2006), the mechanisms underlying this extensive HGT remain poorly understood (Adams et al., 2008; Fournier et al., 2006; Imperi et al., 2011; Ramirez et al., 2010; Wilharm et al., 2013). Here, we show bacterial predation by Acinetobacter baylyi increases cross-species HGT by orders of magnitude, and we observe predator cells functionally acquiring adaptive resistance genes from adjacent prey. We then develop a population-dynamic model quantifying killing and HGT on solid surfaces. We show DNA released via cell lysis is readily available for HGT and may be partially protected from the environment, describe the effects of cell density, and evaluate potential environmental inhibitors. These findings establish a framework for understanding, quantifying, and combating HGT within the microbiome and the emergence of MDR super-bugs.
Collapse
Affiliation(s)
- Robert M Cooper
- BioCircuits InstituteUniversity of California, San DiegoSan DiegoUnited States
| | - Lev Tsimring
- BioCircuits InstituteUniversity of California, San DiegoSan DiegoUnited States
- San Diego Center for Systems BiologyUniversity of California, San DiegoSan DiegoUnited States
| | - Jeff Hasty
- BioCircuits InstituteUniversity of California, San DiegoSan DiegoUnited States
- San Diego Center for Systems BiologyUniversity of California, San DiegoSan DiegoUnited States
- Molecular Biology Section, Division of Biological ScienceUniversity of California, San DiegoSan DiegoUnited States
- Department of BioengineeringUniversity of California, San DiegoSan DiegoUnited States
| |
Collapse
|
8
|
Sousa A, Frazão N, Ramiro RS, Gordo I. Evolution of commensal bacteria in the intestinal tract of mice. Curr Opin Microbiol 2017; 38:114-121. [PMID: 28591676 DOI: 10.1016/j.mib.2017.05.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/28/2017] [Accepted: 05/21/2017] [Indexed: 12/19/2022]
Abstract
Hundreds of different bacterial species inhabit our intestines and contribute to our health status, with significant loss of species diversity typically observed in disease conditions. Within each microbial species a great deal of diversity is hidden and such intra-specific variation is also key to the proper homeostasis between the host and its microbial inhabitants. Indeed, it is at this level that new mechanisms of antibiotic resistance emerge and pathogenic characteristics evolve. Yet, our knowledge on intra-species variation in the gut is still limited and an understanding of the evolutionary mechanisms acting on it is extremely reduced. Here we review recent work that has begun to reveal that adaptation of commensal bacteria to the mammalian intestine may be fast and highly repeatable, and that the time scales of evolutionary and ecological change can be very similar in these ecosystems.
Collapse
Affiliation(s)
- Ana Sousa
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, Oeiras, Portugal; iBiMED, Institute for Biomedicine, Universidade de Aveiro, Portugal
| | - Nelson Frazão
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, Oeiras, Portugal
| | - Ricardo S Ramiro
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, Oeiras, Portugal
| | - Isabel Gordo
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, Oeiras, Portugal.
| |
Collapse
|
9
|
Cheng VCC, Wong SCY, Ho PL, Yuen KY. Strategic measures for the control of surging antimicrobial resistance in Hong Kong and mainland of China. Emerg Microbes Infect 2015; 4:e8. [PMID: 26038766 PMCID: PMC4345289 DOI: 10.1038/emi.2015.8] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 12/30/2014] [Accepted: 12/30/2014] [Indexed: 01/23/2023]
Abstract
Antimicrobial-resistant bacteria are either highly prevalent or increasing rapidly in Hong Kong and China. Treatment options for these bacteria are generally limited, less effective and more expensive. The emergence and dynamics of antimicrobial resistance genes in bacteria circulating between animals, the environment and humans are not entirely known. Nonetheless, selective pressure by antibiotics on the microbiomes of animal and human, and their associated environments (especially farms and healthcare institutions), sewage systems and soil are likely to confer survival advantages upon bacteria with antimicrobial-resistance genes, which may be further disseminated through plasmids or transposons with integrons. Therefore, antibiotic use must be tightly regulated to eliminate such selective pressure, including the illegalization of antibiotics as growth promoters in animal feed and regulation of antibiotic use in veterinary practice and human medicine. Heightened awareness of infection control measures to reduce the risk of acquiring resistant bacteria is essential, especially during antimicrobial use or institutionalization in healthcare facilities. The transmission cycle must be interrupted by proper hand hygiene, environmental cleaning, avoidance of undercooked or raw food and compliance with infection control measures by healthcare workers, visitors and patients, especially during treatment with antibiotics. In addition to these routine measures, proactive microbiological screening of hospitalized patients with risk factors for carrying resistant bacteria, including history of travel to endemic countries, transfer from other hospitals, and prolonged hospitalization; directly observed hand hygiene before oral intake of drugs, food and drinks; and targeted disinfection of high-touch or mutual-touch items, such as bed rails and bed curtains, are important. Transparency of surveillance data from each institute for public scrutiny provides an incentive for controlling antimicrobial resistance in healthcare settings at an administrative level.
Collapse
Affiliation(s)
- Vincent C C Cheng
- Department of Microbiology, Queen Mary Hospital , Hong Kong, China ; Infection Control Team, Queen Mary Hospital , Hong Kong, China
| | - Sally C Y Wong
- Department of Microbiology, Queen Mary Hospital , Hong Kong, China
| | - Pak-Leung Ho
- Department of Microbiology, Queen Mary Hospital , Hong Kong, China
| | - Kwok-Yung Yuen
- Department of Microbiology, Queen Mary Hospital, Hong Kong, China ; Department of Clinical Microbiology and Infection Control, Hong Kong University-Shenzhen Hospital , Shenzhen 518053, Guangdong province, China
| |
Collapse
|
10
|
Scientific Opinion on applications (EFSA-GMO-UK-2008-57 and EFSA-GMO-RX-MON15985) for the placing on the market of insect-resistant genetically modified cotton MON 15985 for food and feed uses, import and processing, and for the renewal of authorisation o. EFSA J 2014. [DOI: 10.2903/j.efsa.2014.3770] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
11
|
Ceuppens S, Li D, Uyttendaele M, Renault P, Ross P, Ranst MV, Cocolin L, Donaghy J. Molecular Methods in Food Safety Microbiology: Interpretation and Implications of Nucleic Acid Detection. Compr Rev Food Sci Food Saf 2014; 13:551-577. [DOI: 10.1111/1541-4337.12072] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 03/09/2014] [Indexed: 11/27/2022]
Affiliation(s)
- Siele Ceuppens
- Faculty of Bioscience Engineering; Laboratory of Food Microbiology and Food Preservation (LFMFP); Dept. of Food Safety and Food Quality; Ghent Univ.; Ghent Belgium
| | - Dan Li
- Faculty of Bioscience Engineering; Laboratory of Food Microbiology and Food Preservation (LFMFP); Dept. of Food Safety and Food Quality; Ghent Univ.; Ghent Belgium
| | - Mieke Uyttendaele
- Faculty of Bioscience Engineering; Laboratory of Food Microbiology and Food Preservation (LFMFP); Dept. of Food Safety and Food Quality; Ghent Univ.; Ghent Belgium
| | - Pierre Renault
- Inst. Scientifique de Recherche Agronomique (INRA); France
| | - Paul Ross
- Moorepark Biotechnology Centre; Teagasc; Moorepark; Fermoy Co. Cork Ireland
| | | | - Luca Cocolin
- Dept. of Agricultural; Forest and Food Sciences; Univ. of Torino; Grugliasco Torino Italy
| | - John Donaghy
- Food Safety Microbiology Group; Nestle Research Center; Lausanne Switzerland
| |
Collapse
|
12
|
Nielsen KM, Bøhn T, Townsend JP. Detecting rare gene transfer events in bacterial populations. Front Microbiol 2014; 4:415. [PMID: 24432015 PMCID: PMC3882822 DOI: 10.3389/fmicb.2013.00415] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 12/16/2013] [Indexed: 11/23/2022] Open
Abstract
Horizontal gene transfer (HGT) enables bacteria to access, share, and recombine genetic variation, resulting in genetic diversity that cannot be obtained through mutational processes alone. In most cases, the observation of evolutionary successful HGT events relies on the outcome of initially rare events that lead to novel functions in the new host, and that exhibit a positive effect on host fitness. Conversely, the large majority of HGT events occurring in bacterial populations will go undetected due to lack of replication success of transformants. Moreover, other HGT events that would be highly beneficial to new hosts can fail to ensue due to lack of physical proximity to the donor organism, lack of a suitable gene transfer mechanism, genetic compatibility, and stochasticity in tempo-spatial occurrence. Experimental attempts to detect HGT events in bacterial populations have typically focused on the transformed cells or their immediate offspring. However, rare HGT events occurring in large and structured populations are unlikely to reach relative population sizes that will allow their immediate identification; the exception being the unusually strong positive selection conferred by antibiotics. Most HGT events are not expected to alter the likelihood of host survival to such an extreme extent, and will confer only minor changes in host fitness. Due to the large population sizes of bacteria and the time scales involved, the process and outcome of HGT are often not amenable to experimental investigation. Population genetic modeling of the growth dynamics of bacteria with differing HGT rates and resulting fitness changes is therefore necessary to guide sampling design and predict realistic time frames for detection of HGT, as it occurs in laboratory or natural settings. Here we review the key population genetic parameters, consider their complexity and highlight knowledge gaps for further research.
Collapse
Affiliation(s)
- Kaare M Nielsen
- Department of Pharmacy, Faculty of Health Sciences, University of Tromsø Tromsø, Norway ; GenØk-Centre for Biosafety, The Science Park Tromsø, Norway
| | - Thomas Bøhn
- Department of Pharmacy, Faculty of Health Sciences, University of Tromsø Tromsø, Norway ; GenØk-Centre for Biosafety, The Science Park Tromsø, Norway
| | - Jeffrey P Townsend
- Department of Biostatistics, Yale University New Haven, CT, USA ; Program in Computational Biology and Bioinformatics, Yale University New Haven, CT, USA ; Program in Microbiology, Yale University New Haven, CT, USA
| |
Collapse
|
13
|
Scientific Opinion on an application from Pioneer Hi‐Bred International and Dow AgroSciences LLC (EFSA‐GMO‐NL‐2005‐23) for placing on the market of genetically modified maize 59122 for food and feed uses, import, processing and cultivation under Regulation (EC) No 1829/2003. EFSA J 2013. [DOI: 10.2903/j.efsa.2013.3135] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
|
14
|
Scientific Opinion on an application (EFSA-GMO-NL-2009-70) for the placing on the market of genetically modified drought tolerant maize MON 87460 for food and feed uses, import and processing under Regulation (EC) No 1829/2003 from Monsanto. EFSA J 2012. [DOI: 10.2903/j.efsa.2012.2936] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
|
15
|
Scientific Opinion on an application (EFSA‐GMO‐NL‐2005‐24) for the placing on the market of the herbicide tolerant genetically modified soybean 40‐3‐2 for cultivation under Regulation (EC) No 1829/2003 from Monsanto. EFSA J 2012. [DOI: 10.2903/j.efsa.2012.2753] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
|
16
|
Nordgård L, Brusetti L, Raddadi N, Traavik T, Averhoff B, Nielsen KM. An investigation of horizontal transfer of feed introduced DNA to the aerobic microbiota of the gastrointestinal tract of rats. BMC Res Notes 2012; 5:170. [PMID: 22463741 PMCID: PMC3364145 DOI: 10.1186/1756-0500-5-170] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 04/01/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Horizontal gene transfer through natural transformation of members of the microbiota of the lower gastrointestinal tract (GIT) of mammals has not yet been described. Insufficient DNA sequence similarity for homologous recombination to occur has been identified as the major barrier to interspecies transfer of chromosomal DNA in bacteria. In this study we determined if regions of high DNA similarity between the genomes of the indigenous bacteria in the GIT of rats and feed introduced DNA could lead to homologous recombination and acquisition of antibiotic resistance genes. RESULTS Plasmid DNA with two resistance genes (nptI and aadA) and regions of high DNA similarity to 16S rRNA and 23S rRNA genes present in a broad range of bacterial species present in the GIT, were constructed and added to standard rat feed. Six rats, with a normal microbiota, were fed DNA containing pellets daily over four days before sampling of the microbiota from the different GI compartments (stomach, small intestine, cecum and colon). In addition, two rats were included as negative controls. Antibiotic resistant colonies growing on selective media were screened for recombination with feed introduced DNA by PCR targeting unique sites in the putatively recombined regions. No transformants were identified among 441 tested isolates. CONCLUSIONS The analyses showed that extensive ingestion of DNA (100 μg plasmid) per day did not lead to increased proportions of kanamycin resistant bacteria, nor did it produce detectable transformants among the aerobic microbiota examined for 6 rats (detection limit < 1 transformant per 1,1 × 10(8) cultured bacteria). The key methodological challenges to HGT detection in animal feedings trials are identified and discussed. This study is consistent with other studies suggesting natural transformation is not detectable in the GIT of mammals.
Collapse
Affiliation(s)
- Lise Nordgård
- GenØk, Centre for Biosafety, Science Park, 9294 Tromsø, Norway
| | | | | | | | | | | |
Collapse
|
17
|
Scientific Opinion on applications EFSA‐GMO‐UK‐2005‐09 and EFSA‐GMO‐RX‐MON531×MON1445 for the placing on the market of food and feed produced from or containing ingredients produced from insect‐resistant and herbicide‐tolerant genetically modified cotton MON 531 × MON 1445, and for the renewal of authorisation of existing products produced from cotton MON 531 × MON 1445, both under Regulation (EC) No 1829/2003 from Monsanto. EFSA J 2012. [DOI: 10.2903/j.efsa.2012.2608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
18
|
Townsend JP, Bøhn T, Nielsen KM. Assessing the probability of detection of horizontal gene transfer events in bacterial populations. Front Microbiol 2012; 3:27. [PMID: 22363321 PMCID: PMC3282476 DOI: 10.3389/fmicb.2012.00027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Accepted: 01/16/2012] [Indexed: 11/23/2022] Open
Abstract
Experimental approaches to identify horizontal gene transfer (HGT) events of non-mobile DNA in bacteria have typically relied on detection of the initial transformants or their immediate offspring. However, rare HGT events occurring in large and structured populations are unlikely to be detected in a short time frame. Population genetic modeling of the growth dynamics of bacterial genotypes is therefore necessary to account for natural selection and genetic drift during the time lag and to predict realistic time frames for detection with a given sampling design. Here we draw on statistical approaches to population genetic theory to construct a cohesive probabilistic framework for investigation of HGT of exogenous DNA into bacteria. In particular, the stochastic timing of rare HGT events is accounted for. Integrating over all possible event timings, we provide an equation for the probability of detection, given that HGT actually occurred. Furthermore, we identify the key variables determining the probability of detecting HGT events in four different case scenarios that are representative of bacterial populations in various environments. Our theoretical analysis provides insight into the temporal aspects of dissemination of genetic material, such as antibiotic resistance genes or transgenes present in genetically modified organisms. Due to the long time scales involved and the exponential growth of bacteria with differing fitness, quantitative analyses incorporating bacterial generation time, and levels of selection, such as the one presented here, will be a necessary component of any future experimental design and analysis of HGT as it occurs in natural settings.
Collapse
Affiliation(s)
- Jeffrey P Townsend
- Department of Ecology and Evolutionary Biology, Yale University New Haven, CT, USA
| | | | | |
Collapse
|
19
|
Rizzi A, Raddadi N, Sorlini C, Nordgrd L, Nielsen KM, Daffonchio D. The Stability and Degradation of Dietary DNA in the Gastrointestinal Tract of Mammals: Implications for Horizontal Gene Transfer and the Biosafety of GMOs. Crit Rev Food Sci Nutr 2012; 52:142-61. [DOI: 10.1080/10408398.2010.499480] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
20
|
Scientific Opinion on application (EFSA-GMO-UK-2008-60) for placing on the market of genetically modified herbicide tolerant maize GA21 for food and feed uses, import, processing and cultivation under Regulation (EC) No 1829/2003 from Syngenta Seeds. EFSA J 2011. [DOI: 10.2903/j.efsa.2011.2480] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
|
21
|
Scientific Opinion on application EFSA-GMO-RX-MON1445 for renewal of the authorisation for continued marketing of cottonseed oil, food additives, feed materials and feed additives produced from cotton MON 1445 that were notified as existing products under. EFSA J 2011. [DOI: 10.2903/j.efsa.2011.2479] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
22
|
Scientific Opinion on application (EFSA-GMO-CZ-2008-54) for placing on the market of genetically modified insect resistant and herbicide tolerant maize MON 88017 for cultivation under Regulation (EC) No 1829/2003 from Monsanto. EFSA J 2011. [DOI: 10.2903/j.efsa.2011.2428] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
|
23
|
Elliott KT, Neidle EL. Acinetobacter baylyi ADP1: Transforming the choice of model organism. IUBMB Life 2011; 63:1075-80. [DOI: 10.1002/iub.530] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 06/09/2011] [Indexed: 11/12/2022]
|
24
|
Scientific Opinion on application EFSA‐GMO‐RX‐MON531 for renewal of the authorisation for continued marketing of existing cottonseed oil, food additives, feed materials and feed additives produced from MON 531 cotton that were notified under Articles 8(1)(a), 8(1)(b) and 20(1)(b) of Regulation (EC) No 1829/2003 from Monsanto. EFSA J 2011. [DOI: 10.2903/j.efsa.2011.2373] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
25
|
Wilcks A, Jacobsen BB. Lack of detectable DNA uptake by transformation of selected recipients in mono-associated rats. BMC Res Notes 2010; 3:49. [PMID: 20193062 PMCID: PMC2845597 DOI: 10.1186/1756-0500-3-49] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Accepted: 03/01/2010] [Indexed: 11/10/2022] Open
Abstract
Background An important concern revealed in the public discussion of the use of genetically modified (GM) plants for human consumption, is the potential transfer of DNA from these plants to bacteria present in the gastrointestinal tract. Especially, there is a concern that antibiotic resistance genes used for the construction of GM plants end up in pathogenic bacteria, eventually leading to untreatable disease. Findings Three different bacterial species (Escherichia coli, Bacillus subtilis, Streptococcus gordonii), all natural inhabitants of the food and intestinal tract environment were used as recipients for uptake of DNA. As source of DNA both plasmid and genomic DNA from GM plants were used in in vitro and in vivo transformation studies. Mono-associated rats, creating a worst-case scenario, did not give rise to any detectable transfer of DNA. Conclusion Although we were unable to detect any transformation events in our experiment, it cannot be ruled out that this could happen in the GI tract. However, since several steps are required before expression of plant-derived DNA in intestinal bacteria, we believe this is unlikely, and antibiotic resistance development in this environment is more in danger by the massive use of antibiotics than the consumption of GM food harbouring antibiotic resistance genes.
Collapse
Affiliation(s)
- Andrea Wilcks
- Division of Microbiology and Risk Assessment, National Food Institute, Technical University of Denmark, Mørkhøj Bygade 19, DK-2860 Søborg, Denmark.
| | | |
Collapse
|