Donald S. Frederickson, M.D. 
2 
The most important changes in the recent guideline revision include 
the reduction in physical containment levels from P3 or P4 for many 
experimental systems and the exemption of certain other systems from 
the guidelines. These changes allow safe, independent investigation 
by scientists in public and private institutions throughout the country 
without tremendous expenditures of limited research funds to construct 
high containment facilities. Review of research by a local Institutional 
Biosafety Committee (IBC) is endorsed, since this process places the 
initial review with the scientists having expertise not only in genetics 
and nucleic acid research but also in local laboratory facilities and 
practices. It also provides for input from non-science faculty and 
the local citizenry. Through our Science and Education Administration 
(Cooperative Research) , USDA is assisting colleges and universities in 
establishing IBC’s and identifying agricultural scientists who have 
been appointed to the Committees. We had already taken steps to assure 
that guidelines were followed for all USDA supported research, and will 
continue to do so under the revised guidelines. 
A few points in the guidelines have been singled out for direct comment. 
Under Exemption I-E-4, experiments with certain bacterial genera known 
to exchange DNA with E. coli are exempt from the guidelines. However, 
the list of exchangers in Appendix A did not include Xanthomonas , a 
bacterial plant pathogen which the Risk Assessment Workshop considered 
to be an exchanger. We anticipate a need to add Xanthomonas to this 
list in the future and thus feel it would be beneficial to have a 
clarification of the criteria for gene exchange better defined in the 
guidelines . 
The anticipated potential of recombinant DNA in agriculture will be 
difficult if not impossible to realize with the E^_ coli K-12 host-vector 
system. Therefore, it is imperative that attention be given to the 
development and approval of alternate HV-1 systems that may be useful 
in genetic engineering of plants and invertebrates . 
The Department agrees with the need and purpose of prohibiting certain 
experiments at this time, but wishes to comment on two of the prohibited 
experiments in the revised guidelines as they have a direct bearing on 
agriculture. Plant pathogens are known to have a wide variability in 
virulence and host range that corresponds to the genetic diversity of 
their host plants. The ability to manipulate virulence by any means, 
including recombinant DNA, is important to the understanding of the 
biochemical and physiological basis for virulence. Since the precision 
that is possible with recombinant DNA may provide a powerful research 
tool, waiver of this prohibition to enable research on virulence to 
proceed should be considered by USDA and NIH for inclusion in this 
revision of the guidelines. 
[A-392] 
