2 
Dr. Gottesman called the meeting of the Working Group on Toxins to order at 
9:05 a.m. on May 11, 1984. She said the working group was to review a proposal 
to lower containment conditions for the cloning of the Shiga-like toxin gene in 
E. ooli K-12 host-vector systems. 
Dr. Gottesman recounted the history of the proposal. In September 1982, 
Dr. Alison O'Brien of the Uniformed Services University of the Health Sciences 
(USUHS) requested permission in collaboration with Dr. Randall Holmes of USUHS 
to clone in Escherichia coli K-12 the structural gene of the Shiga-like toxin 
from clinically isolated strains of Eh_ coli . The Eh_ ooli Shiga-like toxin has 
activity similar to the activity of Shigella dysentenae toxin. The investiga- 
tors proposed to clone the Shiga-like toxin gene in Eh_ coli EK1 host-vector 
systems using plasmid, cosmid, or lambda cloning vectors. 
The request was summarized in the Federal Register of September 22, 1982, 
(47 FR 41924). The RAC discussed the request submitted by Dr. O'Brien at the 
October 25, 1982, meeting. 
The NIH accepted the RAC recommendation of the October 25, 1982, meeting that 
P4 + EK1 containment is adequate to contain safely the experiments proposed by 
Drs. O'Brien and Holmes and appropriate language was added to Appendix F of the 
Guidelines. The language stipulated that if the investigators wish to proceed 
with the experiments in the National Institutes of Health (NIH) P4 facility a 
prior review would be conducted to advise the NIH on whether the proposal had 
sufficient scientific merit to justify the use of the NIH P4 facility. A 
subsequent review by the Bacteriology and Mycology Study Section of the NIH 
indicated that the proposal had sufficient scientific merit. 
"Drs. O'Brien and Holmes then requested in a letter dated December 8, 1983, 
reconsideration of containment levels in view of information which had become 
available. They requested permission to conduct experiments at the P2 level 
of physical containment. 
The proposal was published in the January 5, 1984, Federal Register (49 FR 696) 
and RAC reviewed the proposal of Drs. O'Brien and Holmes at its February 6, 
1984, meeting. 
By a vote of nine in favor, five opposed, and four abstentions, the RAC 
recommended that Drs. O'Brien and Holmes and ccworkers be allowed to proceed 
with cloning the gene for Shiga-like toxin under P2 physical containment condi- 
tions in ^ coli K-12 restricted to using EK2 plasmid vectors commencing first 
with the use of pBR325 and pBR322 and proceeding to other EK2 plasmid vectors 
only if those are unsatisfactory. 
By a vote of eight in favor, four opposed, and five abstentions, the RAC passed 
the same motion but with the names of the investigators deleted from the motion 
As it has been the practice of the NIH not to accept RAC recommendations that 
do not indicate a clear consensus, this RAC recommendation was not accepted. 
The investigators, however, already had approval to conduct these experiments 
[ 411 ] 
