Memorandum to: The Record - page 2 
September 4, 1979 
present some unexpected hazard. It was the Group's judgement that, 
based on their collective expertise in microbial genetics and infectious 
disease, they could not foresee how recombinant DNA technology as currently 
practiced could confer pathogenic properties on recipient E^. col i . 
Therefore, it was recommended that the Institute should not develop or 
support new experimental models to pursue this unlikely possibility. 
During discussion of the issues cited above it was obvious that the 
Working Group felt that a more beneficial use of monies would be to 
support the training of workers in good microbiological laboratory 
practices and to support research aimed at gaining a better basic 
scientific understanding of bacterial colonization and plasmid mobilization. 
Toward this last goal the Working Group strongly recommended that the 
NIAID support studies that can obtain quantitative data, will expand the 
scientific knowledge in an important area and which may prove useful at 
some future date for risk assessment. The Group felt that such studies 
should be performed directly in humans and employ wild type E. col i (not 
K12). Strain HS containing pBR325 was suggested as a good initial 
combination and the study should be developed to assay for both survival 
and transfer to the indigenous flora. 
The Working Group expressed their solid support for the proposed 
exemption of K12 based cloning from the Guidelines providing that PI 
laboratory practices were employed uniformly in conducting this and 
other categories of exempted research. This issue will be considered by 
the RAC on September 6 and 7, 1979 and is basically embodied in Item 
No. 706. 
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