2 
l4>4u&> for l ihz Conmcttzz'4 Coni^deAatlon 
1. On p. 11 of the guidelines, new language is suggested to strengthen 
the wording of section (v) and leave no uncertainty with respect 
to the committee's intent in this regard: "Transfer of drug 
resistance traits to microorganisms that are not known to acquire 
them naturally should be deferred if they could compromise the 
present or future use of a drug to control agents that cause 
disease in any species of animals or plants . " 
2. On p. 28 of the guidelines, the following paragraph appears that 
relates to prokaryotes which do not exchange genetic information 
with _E. coli : "Experiments extending the range of resistance to 
therapeutically useful drugs and disinfectants should use P2 + EK2 
containment or higher depending on the virulence of the donor." 
On p. 31 of the guidelines, the following statement appears 
concerning plasmids and phage from hosts that do not exchange 
genetic information with _E. coli : "Experiments with DNA 
recombinants formed with foreign plasmids or phage containing 
genes which extend the range of resistance of the recipient to 
therapeutically useful drugs should use P3 physical containment + 
an EK2 host-vector." 
These respective sections of the guidelines present certain 
problems that merit the committee's attention: First, there 
appears to be an internal discrepancy in stated containment 
levels in these latter two sections. Should not the containment 
levels for both be at P3 and EK2? The second problem, which is 
more serious in my view, is the relationship of these two sections 
to the prohibition as stated on p. 11. Was it the committee's 
intent to allow experiments where _E. coli might be made resistant 
to therapeutically useful drugs (to which _E. coli is not now 
known to be resistant)? If that is the committee's intent, 
then it would appear to be in conflict with the prohibitions 
stated on p. 11. I would appreciate the committee's opinions 
on this matter. 
3. The guidelines state on p. 11, a prohibition of experiments 
using the DNA of pathogenic agents in Classes 3, 4, and 5 of 
the CDC Manual. Would the committee have any objection to 
broadening this to include not only their DNA, but also the 
DNA from any organism infected with these agents? 
[ 409 ] 
