viable organism. Another potentially hazardous situation would 
occur if a non-pathogenic culture become contaminated with a 
virulent species . The researcher could continue to treat 
it as harmless, subjecting it to treatment causing aerosols 
etc., and not subject it to the stricter containment care it 
should receive. No periodic check for culture purity is 
recommended in the DEIS or the Guidelines. The Guidelines must 
require a continual checking of host organisms to ensure that 
they always contain the full compliment of disabling characteristics. 
Roy Curtiss' X 1776 strain was well known when the DEIS 
was issued, yet no mention of it appears in the DEIS. An 
objective discussion of this strain would have presented the reader 
with a better understanding of what can and cannot be expected of 
a disarmed host organism. One of the disabling characteristics of 
this strain is its inedsility to manufacture a cell wall. The 
DEIS never discuss alternate strategies for disabled organisms 
to propagate. One such circumvention mechanism which should 
have been mentioned is the ability of some bacteria that 
have defective cell walls to spontaneously give rise to L form 
variants that can replicate in the form of small filterable 
elements without cell walls. Another diseibling characteristic 
of the X 1776 strain which is claimed to ensure safety is its 
bile salt sensitivity and other lysing traits in outside 
environments . What should be pointed out is that the naked 
DNA resulting from the lysed cell could act as a contaminant by 
combining with amother cell by means of transformation. 
-18- 
Appendix K — 98 
