Safety evaluation of horizontal gene transfer from genetically modified organisms to the microflora of the food chain and human gut


A Review of EC-supported Research on Safety of GMOs

Project title:

Safety evaluation of horizontal gene transfer from genetically modified organisms to the microflora of the food chain and human gut
Name of EC programme: Quality of Life and Management of Living Resources
Contract number: QLK1-CT-1999-00527
Type of contract: Shared cost action (SC)
EC funding: 1.488.115 euro
Contract start date: (01/02/00)
Contract end date: (01/02/03)
Related projects: this project was linked/related, formally or informally, through the thematic network ENTRANSFOOD

Jos M.B.M. van der Vossen
Department Food Microbiology and Quality management,
TNO Nutrition and Food Research Institute,
Utrechtseweg 48,
3704 HE Zeist NL
Fax: +31 30 6944901
Website address:

Dr. H.J.M. Aarts Prof. Dr. Walter P. Hammes
State Institute for Quality Control of Agricultural products (RIKILT) Institute of Food Technology,
University of Hohenheim,
Bornsesteeg 45 Garbenstraße 28,
PO BOX 230 70599 Stuttgart, D
6700 AE Wageningen NL Fax: +49 711 459 4199
Fax: +31 317 417717 E-mail:
E-mail: Internet:
Dr. Gerard Corthier Dr. Bodil Lund Jacobsen
UEPSD - Fonctions des Bacteries Intestinales Division of Microbial Safety Institute of Food
Institut National de Recherches Agronomiques (INRA) Safety and Toxicology                                           DANISH VETERINARY AND FOOD
78350 Jouy-en-Josas, F Mørkhøj Bygade 19
Fax : +33 (0) DK 2860 Søborg, Dk
E-mail: Fax +45 33956699
Internet: Email:
Dr. Alexander Haslberger
Institute for Microbiology and Genetics,
University Vienna
Dr. Bohrgasse 9
A-1030 Vienna, A
Fax: +43 1 31991484 ext 234

Scientific content


The main objective of the project is to quantify the risk of horizontal gene transfer (HGT) from GMO and food derived thereof to the microflora of the food chain and the human gut. Apart from analysis of transfer frequencies, hazards will be identified, exposure data will be collected and the impact will be addressed to quantify the risk of HGT and to be conclusive. Selective conditions are particularly relevant for antibiotic resistance marker genes. Therefore, the relevance of a particular antibiotic as therapeutic agent will be dealt with in the risk evaluation. This project aims also on evaluation of models to study these HGT events.

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Scientific background

HGT as a biosafety issue has been addressed in several studies mainly focused on the transfer of antibiotic resistance from GM plants to soil- and plant related microorganisms. HGT to bacteria in these environments was only shown by marker rescue experiments via homologous recombination.

HGT via transformation of bacteria in the food chain can not be excluded. In some matrices free DNA persists for weeks. In addition, some bacteria develop natural/chemical competence. Also in the gastrointestinal tract, DNA may remain stable for some times particularly in the colon.

Approach used and methodology

To collect the data on HGT, food, in vivo and in vitro GI-tract model systems will be studied, evaluated and validated for the evaluation HGT from transgenic food products. Since genes can be transferred via different mechanisms depending on the genetic background, different donor/recipient systems will be studied. In addition to the mechanisms additional parameters in the frequency of HGT will be analysed such as survival of bacteria, stability of DNA, development of competence for transformation, possibility for recombination, and selective pressure. The collected data will be evaluated to quantify the risk of HGT based on the genetic background, daily intake of transgenic DNA, formulation of the food product, and the nature of marker genes.

Structure of the project

Project is structured by the definition of five work packages:

WP1 Selection, construction and lab bench testing of donor sequences and recipient strains for horizontal gene transfer
WP2 Horizontal gene transfer in food systems
WP3 Horizontal gene transfer in in vitro model systems
WP4 Horizontal gene transfer in vivo
WP5 Quantitative risk assessment and evaluation of model systems


Latest update: 17-12-2002

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