13 
Guidelines addresses the deliberate introduction of drug resistance treats to 
organisms which would not ordinarily naturally acquire it in any other way if 
the acquisition could ccmpr anise the use of the drug to control disease agents 
in human or veterinary medicine or agriculture. 
Dr. Macrina did not think organisms created in the laboratory by the intro- 
duction of antibiotic resistance genes would be worse than those found in 
nature. He thought the potential for assortment of colonization and virulence 
factors exists in nature. 
Dr. Pattee noted that ch ratios cma 1 ly located pathogenicity determinants do not 
appear to be transferring from organism to organism in nature. 
Dr. Dean asked whether any additional issues cure raised by cloning antibiotic 
resistance genes on shuttle vectors. Dr. Friedman said Section III-A-3 would 
address that issue. 
Dr. Gottesman suggested the third option could be constructed under Section 
III-D-5 of the NIH Guidelines; the language could appear as Appendix C-V, 
Extrachromosomal Elements of Gram-Positive Organisms . 
Over lunch a sutworking group developed the following proposed language : 
"Recombinant DNA molecules derived entirely from extrachromosomal elements 
of the organisms listed below including shuttle vectors with E^ coll 
repliccns that cure propagated and maintained in organisms listed below are 
exempt from these Guidelines." 
Dr. Thcmashow said two rationales support this recommendation: (l) data 
demonstrate extensive intergeneric transfer of broad host-range plasmids; and 
(2) data demonstrate intergeneric transfer of nonconjugative plasmids between 
the organisms on the list. 
Dr. Baltz asked whether use of shuttle vectors constructed frcm fh_ cerevisiae 
repl icons would be acceptable and could be added to the language. Dr. Dean 
agreed with this position. He felt cerevisiae ENA might be part of useful 
shuttle vectors. He suggested DNA frcm organisms described in Appendix C, i.e. , 
E. ooli K-12, cerevisiae , and asporogenic subtilis be exenpted when 
part of shuttle vectors. 
Dr. Cohen said an argument for permitting use of shuttle vector ENA in gram- 
positive organisms is that these shuttle vectors are well-known safe vectors 
vhich have been extensively studied in Eh_ ooli and/or cerevisiae , or their 
native hosts. Dr. Thorne said these vectors do not have any toxic or bio- 
logically hazardous characteristics. 
Dr. Thcmashow questioned vhether the word "replicon," a rather undefined term, 
should be part of the language of this recommendation. Dr. Baltz suggested 
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