12 
He suggested it would also be very helpful if shuttle vectors composed of E. 
ooli and cerevisiae ENA could be ex ergot when used with these organisms and 
broad host-range plasmids. Dr. Thomashcw agreed. 
Dr. Lovett said seme data demonstrate that one of the broad host-range gram- 
positive plasmids replicates in EL_ coli and cereviseae. 
Dr. Gottesman thought a proposal including shuttle vectors ccnposed of Jh_ ooli 
and S^ cerevisiae DNA would be acceptable. She noted that earlier versions of 
the NTH Guidelines permitted DNA cloned in Eh_ ooli to be "returned to host of 
origin" with the plasmid vector. This language permitted the investigator 
to clone ENA in EL_ ooli host-vector systems and return the vector containing 
the cloned DNA to the original ENA source organism without considering the 
effect of the vector ENA on the host of origin. She suggested language concern- 
ing the use of shuttle vectors could be added to the third option. 
Dr. Macrina said he preferred the first option although he did not knew if 
sufficient information exists to support this position. He felt the third 
option could for the most part already be found in the NIH Guidelines. 
Dr. Lovett supported the first option; he felt extensive plasmid exchange 
occurs in the gram-positive bacteria although there are no mechanisms currently 
known which permit chromosomal gene exchange by these plasmids. 
Dr. Cohen felt not enough information is available to support the first option. 
Dr. Thcmashcw did not think the working group should offer a recormendation 
which cannot be supported by data. 
Dr. Clewell said the third option does have merit; it would simplify the situ- 
ation for large-scale procedures and would clarify the language of the NIH 
Guidelines concerning use of these types of broad host-range plasmids. He did 
not think sufficient evidence of chromosomal exchange exists to support the 
first option and noted that significant human pathogens are in this group of 
bacteria. 
Dr. Thome said philosophically he supported the first option but did not feel 
sufficient evidence existed to support a recormendation exempting organisms from 
the NIH Guidelines on the basis of chromosomal gene exchange. He, therefore, 
recommended the working group develop the third option. 
Dr. Cohen asked hew Section III-A of the NIH Guidelines inpacts Appendix A. 
Would the presence of drug resistance genes on broad host-range plasmids present 
a problem for a recommendation exenpting these plasmids used in gram-positive 
bacteria? 
Dr. Gottesman replied that Section III-A, Experiments Which Require Specific 
RAC Review and NIH and IBC Approval Before Initiation of the Experiment , over- 
rides other sections of the NIH Guidelines; experiments which are covered by 
both Section III-A and III-D would not be exempt. Section I II -A- 3 of the NIH 
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