36 
Dr. Formal 
Dr. Formal discussed his knowledge of the transmissibility of E. coli 
in human beings. As he pointed out, the growth and development of 
this organism in various individuals will vary depending upon a num- 
ber of conditions. While the causation of E. coli induced disease which 
occurs at times is not fully understood, in a few instances, the charac- 
teristics of the strains which produce some diseases are reasonably 
well defined. In the work being conducted, the properties of E. coli 
which are believed to be associated with the induction of disease have 
been deliberately added to non-virulent strains, such as the K-12 used 
in DNA recombinant work, in attempts to convert this strain to a 
virulent variant. These attempts have failed. Although their group is 
continuing the studies to identify and replace all of the factors needed 
to induce virulence in the K-12 strain, they have not been successful. 
According to Dr. Formal, this suggests that there are a large number 
of genetic factors which must function in concert in order for the K-12 
strain to recover the capacity to survive outside of the laboratory 
environment and induce disease. 
Despite this long history of work with E. coli variants there has 
never been any incidence in which an epidemic has occurred. In re- 
sponse to a remark that the failure to keep records might be the reason 
for this lack of evidence rather than an mability for the organism to 
infect, Dr. Formal indicated that he believed that while the spread of 
nonpathogenic organisms would be difficult to monitor in any event, 
the evidence which is available strongly suggests there should be little 
concern about causing a disease with the K-12 variant. However, as 
pointed out by both Dr. Pieczenik and Dr. Charache, care must be 
taken to insure that traits are not transmitted to the laboratory strain 
which would permit it to infect other more pathogenic strains. Such 
steps have been outlined in the NIH guidelines. 
Dr. Curtins 
With regard to the risks of epidemics from recombinant work with 
E. coli, Dr. Curtiss suggested that at least three events must occur in 
order for this type of risk to occur. First, the organisms must move 
from one individual to another and infect; second, the organism must 
be able to establish itself in the individual to cause the disease ; and 
finally, the organism must be able to overcome the defense mecha- 
nisms of the host. He indicated that some experiments now completed 
suggest that the probability of these three factors occurring under the 
conditions established for DNA work is very low, measurable, but not 
as likely an event as might be implied by opponents of the research — 
in other words not an unacceptable societal risk. 
Dr. ~Wald 
Dr. Wald, in commenting on Dr. Barkley’s statement on laboratory 
accidents, emphasized that since there is really no routine method for 
monitoring the transmission of diseases between laboratory and home 
or community, or for monitoring the health of workers and their 
families, it is difficult to state that this has never happened. [This is 
a point made by others concerned with the problem of monitoring the 
on-going research in laboratories since there is now no standard 
method procedure.] 
[Appendix B — 85] 
