APPENDIX M 
Dr. Donald Frederickson 
July 14. 1977 
Approximately fifty invited participants and observers (see appended 
roster), from the United States and abroad, with expertise in clinical 
infectious diseases, enteric bacteriology, epidemiology, gastroenterology, 
endocrinology, immunology, bacterial genetics, and animal virology, were 
in attendance at the Falmouth meeting. The invitees were not selected on 
the basis of their particular expertise in molecular biology or for their 
interest in recornb'inant DNA experimentation, but rather because they 
were recognized as authorities in their respective fields. In some 
instances, the participants represented disciplines of biomedical science 
from which little or no input had yet emerged during the recombinant DNA 
debate. 
Consensus Agreement 
An important consensus was arrived at by the assembled group which I 
felt was of sufficient interest to be brought directly to your attention. 
The participants arrived at unanimous agreement that E. col i K12 cannot be 
converted into an epidemic pathogen by laboratory manipulations with DNA 
inserts. On the basis of extensive studies already completed, it appears 
that E. coli K12 does not implant in the intestinal tract of man. There 
is no evidence that non-transmissible plasmids can be spread from E. coli 
K12 to other host bacteria within the gut. Finally, extensive studies in 
the laboratory to induce virulence in E. coli K12 by insertion of known 
plasmids and chromosomal segments coding for virulence factors, using 
standard bacterial genetic techniques, have proven unsuccessful in 
producing a fully pathogenic strain. As a result of these discussions, 
it was believed that the proposed hazards concerning E. coli K12 as an 
epidemic pathogen have been overstated. Such concerns are not compatible 
with the extensive scientific evidence that has already been accumulated, 
all of which provides assurance that E. coli K12 is inherently enfeebled 
and not capable of pathogenic transformation by DNA insertions. 
Summary of the Workshop Sessions Concerning the Biology of E. coli 
The first one-half of the meeting was devoted to a discussion of the 
biology of E . col i and consisted of a series of short presentations dealing 
with the epidemiology of E. coli infections; bacterial cell surface 
virulence factors; toxin production of E . coli ; intestinal colonization and 
invasion; factors influencing the virulence of E. coli ; host defense 
mechanisms; the effect of antibiotics on the ecology of enteric bacteria 
and their plasmids; E. coli challenge experiments in man; feeding 
experiments with E. coli K12 containing known virulence genes from other 
enteric bacteria; and the transmissibi 1 ity of plasmid elements. 
The remainder of the meeting was devoted to planning risk assessment 
experiments in order to: (1) further clarify some of the basic biology of 
E. col i (i .e. , areas in which further information is still needed as 
revealed during the initial session); and (2) ascertain what potential 
hazards, if any, are associated with E. coli K12 containing recombinant DNA. 
Appendix M--2 
