Dr. William Gartland 
May 11, 1979 
Page Three 
believe that the Recombinant Advisory Committee should use these alternate means 
to approve use of a specified M13 or fl EK1 system. Such specifications to im- 
prove biological containment might include use of vectors with amber mutations 
and/or hosts that synthesize F pi 1 i due to the presence of either a A traDI 
mutation in either an autonomous or integrated conjugative plasmid or a recombi- 
nant nonconjugative vector containing only the tra genes necessary for pi 1 i 
synthesis. 
Item 6 - Proposed exemption under I-E-5 for experiments involving EK1 and EK2 
host-vector systems. I am opposed to this proposal, which I consider to be pre- 
mature. Approval of this exemption would in fact allow investigators now 
engaged in recombinant DNA research to return to old habits if they choose and 
utilize "P-zero" containment wherein cultures are poured down the drain prior to 
decontamination or sterilization. I believe this situation would be a likely 
consequence of this exemption for some individuals since there are a growing num- 
ber of recombinant DNA researchers who are concluding, in the absence of very 
much scientific data to substantiate the conclusion, that there is absolutely no 
hazard whatsoever td any_ recombinant DNA research. One of the reasons used as 
a basis for the January 2, 1979 lowering of levels of physical and biological 
containment for many experiments using £. col i K-12 host-vector systems was the 
absence of any detectable biohazard during the first four years of using recombi- 
nant DNA technology. I had previously stated that, while reassuring, the pre- 
viously required leveTs of physical and biological containment would have minimized 
detection of such biohazards should they occur thus minimizing the importance of 
such negative results. I realize that the RAC and the Director of NIH have dis- 
counted, in part, my arguments against relying on such negative results but I 
find it even more difficult to believe that 3 months experience with the lowered 
levels of containment permitted by the revised Guidelines has provided a sufficient 
amount of additional negative results on absence of biohazards to justify complete 
removal of essentially all containment requirements for recombinant DNA research 
with E_. col i K-12 host-vector systems (except for use of EK1 host-vector systems). 
At the Falmouth Conference, it was generally agreed that one could not convert 
E_. col i K-12 to an epidemic pathogen. Since 1977, I have not learned of any 
information to change that assessment. On the other hand, in spite of informa- 
tion presented by E. S. Anderson, H. W. Smith and myself at the conference and 
by S. Falkow and colleagues in the published conference proceedings, there was 
still a degree of concern and uncertainty expressed by the participants on the 
actual likelihood and consequences of transmission of recombinant DNA from E_. 
col i K-12 hosts and vectors to other microorganisms. Since 1977, a number of 
studies have been conducted which indicate that the overall probability for 
transmission of recombinant DNA from E_. col i K-12 hosts and vectors is higher 
than I or others believed. First, I have been told that the British observed 
excretion of EK1 hosts for several weeks from 6 of 24 human volunteers, a re- 
sult that indicates that individual differences may predominate in determining 
the likelihood for colonization and persi stance of K-12 strains in the in- 
testine. Second, R. Freter, S. Levy and ourselves have observed colonization 
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