MINUTES OF MEETING - March 6-7 
7 
Dr. Baltimore questioned whether an experiment using the HS strain could 
be related to recombinant DNA experiments employing K-12 host-vector 
systems. Dr. Gottesman said that the experiments involving Escherichia 
coli strain HS would be useful, since baseline numbers for mobilization 
frequencies in the gut would be generated. Dr. Williams said that he 
agreed with the recommendations advanced by the NIAID Risk Assessment 
Working Group. 
Dr. Susan Wright from the University of Michigan, asked whether Dr. Stuart 
Levy of Tufts University had looked for the transfer of plasmids from 
Bacteriodes to Escherichia coli . Dr. Falkow responded that he did not 
believe that Dr. Levy had. Dr. Young said he was aware of at least 
three instances in which such transfer had been demonstrated. Dr. Wright 
questioned whether the Escherichia coli HS strain was proposed for study 
because industry wants to use it. Dr. Falkow responded that the HS strain 
was chosen because it was fed to more human volunteers than any other 
strain and was known to be harmless. He presumed industry would prefer to 
work with Escherichia coli K-12 as the organism is so well characterized. 
Dr. Williams moved acceptance of the NIAID Risk Assessment Working Group 
report regarding (1) the recommendations on protocols I, II and III, and 
(2) the proposal to perform risk assessment experiments with Escherichia 
coli strain HS. The motion was carried by a vote of twenty in favor, 
none opposed, and two abstentions. 
V. PROPOSED EK2 HOST-VECTOR SYSTEMS 
Dr. Campbell began the discussion of tab 820 (843/15). He said that 
Dr. Pouwels of the Netherlands had requested EK2 and possibly EK3 certi- 
fication of several plasmids derived from plasmid pBR345. He noted that 
Dr. Pouwels had not specified the host to be used as part of the host- 
vector system. Dr. Gottesman said that mobilization data should be 
supplied by Dr. Pouwels. Dr. Campbell questioned the desirability of 
certifying new EK2 systems at this time. Dr. Gottesman said that in 
special cases such EK2 systems might be preferable, as the preposed plas- 
mids do not carry antibiotic resistance markers. She said she thought 
testing to meet EK3 criteria was unreasonable at the present time. She 
suggested that before the RAC requests additional information from 
Dr. Pouwels, the Committee should decide whether certifying a new EK2 
system is worthwhile. She moved that the RAC continue certifying EK2 
systems. This motion was approved by a vote of twenty in favor, one 
opposed, and two abstentions. Dr. Gottesman then moved that the proposal 
be referred to the Plasmid Subcommittee to specify the additional data 
required of Dr. Pouwels, to request the data, to evaluate it, and to 
report back to the RAC. The motion passed by a vote of twenty in favor, 
one opposed, and one abstention. 
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