The European Food Safety Authority (EFSA) was informed on 23 March 2005 of the inadvertent release in the United States of a non-authorised genetically modified (GM) maize line called Bt10, and its unintended export as Bt11 for research purposes to Spain and France.

According to Syngenta, the biotechnology company that has developed Bt10 and Bt11 maize, the two new proteins (Cry1Ab and PAT) expressed in Bt10 and Bt11 are identical. Bt11 maize is authorized in the European Union (EU) for use in food and feed following advice from the former EU Scientific Committees (SCP 2000[1], SCF 2002[2]). However, contrary to Bt11, Bt10 contains a gene (blaTEM) conferring resistance to the antibiotic ampicillin.

EFSA’s Panel on Genetically Modified Foods (GMO Panel) is currently undertaking an assessment of an application[3] for the use of Bt11 in cultivation. Upon being made aware of the inadvertent release of Bt10 maize, the GMO Panel immediately sought information from the applicant to confirm that the risk assessment of Bt11 maize would not be compromised by the unintended presence of Bt10 maize.

EFSA is working in close collaboration with the European Commission on issues related to the safety of Bt10 maize. In this respect, EFSA would like to underline the following points:

• In April 2004 EFSA published an Opinion on the use of antibiotic resistance marker genes in genetically modified plants4 in the context of the Directive 2001/18/EC which states that the future development of genetically modified (GM) plants to be placed on the market and to be used in the production of food or feed should aim at avoiding genes which confer resistance to antibiotics of clinical importance in human
  and veterinary medicine. The GMO Panel concluded that the ampicillin resistance gene should not be present in future GM plants to be placed on the market and that it should be restricted to those used in field trials only. However, the Panel also concluded that the presence of the ampicillin resistance marker gene in a GM crop is unlikely to alter the existing pool of bacteria resistant to this antibiotic significantly
  which, in itself, is an important consideration with regard to any risk posed by the use of the ampicillin resistance gene as marker genes. This is further supported by the fact that no gene transfer from transgenic maize carrying the ampicillin resistance marker gene to culturable bacteria has been detected under field conditions5.
   

• The assertion that, with the exception of the presence of the marker gene conferring resistance to ampicillin, Bt10 is similar to Bt11 has yet to be confirmed. Both EFSA and the European Commission have therefore requested that Syngenta release full information about the safety characteristics of Bt10 and its distinction from Bt11 for further evaluation.

For more background information about the European Food Safety Authority, go to: http://www.efsa.eu.int

[1] Opinion of the Scientific Committee on Plants on the submission for placing on the market of genetically
modified insect resistant and glufosinate ammonium tolerant (Bt-11) maize for cultivation. Notified by
Novartis Seeds SA Company (notification C/F/96/05-10). 30 November 2000.
http://europe.eu.int/comm/food/fs/sc/scp/out86_gmo_en.html

[2] Opinion of the Scientific Committee on Food on a request to place genetically modified sweet maize line
Bt11 on the market (expressed on 17 April 2002). http://europe.eu.int/comm/food/fs/sc/scf/out129_en.pdf

[3] EFSA-Q-2004-012, application under Directive 2001/18/EC

[4] Opinion of the Scientific Panel on Genetically Modified Organisms on the use of antibiotic resistance
genes as marker genes in genetically modified plants, The EFSA Journal (2004) 48, 1-18
http://www.efsa.eu.int/science/gmo/gmo_opinions/384_en.html

[5] Opinion of the Scientific Panel on Genetically Modified Organisms on a request from the Commission
related to the Austrian invoke of Article 23 of Directive 2001/18/EC, The EFSA Journal (2004) 78, 1-13.
http://www.efsa.eu.int/science/gmo/gmo_opinions/507/opinion_gmo_safeguard_clauses_austria_en1.pdf