8 
Rosenberg and Siiion judged to be positive results were what Rowe and 
Martin considered the controls for the experiment. 
Mr. Pauter asked if studies to elucidate aspects of survival and colon- 
ization of different strains of ^ coli would be undertaken. Dr. Krause 
pointed out that the plan states that NIAID has awarded a grant bo an 
investigator to study the molecular mechanisms of coli colonization, 
specifically the relative inportance of plasmid or chromosanal determinants 
CXI cx)lonization. Dr. Levine said this field is very fertile and developing 
very rapidly. 
Mr. Ihomton called on Dr. Holmes to review tab 963, a paper entitled 
"Genetic Diversity and Structure in Escherichia cx>li Papulations." 
Dr. Holmes said that in this article investigators surveyed twenty enzymes 
frcxn one hundred nine clones of ^ coli . In addition to the wild type 
isolates, twenty-four laboratory K-12 strains were studied. Tlie genetic 
diversity the investigators observed led them to ccxiclude that recombin- 
ation in nature, of the genes coding for the studied proteins, is rare. 
One of the ^ coli isolates had been obtained frcxn an infant in a 
Massachusetts hospital nursery. Tlie twenty ass^ed enzymes from this 
strain were indistinguishable electrcphoretically frcxn the same twenty 
enzymes in laboratory strain ^ coli K-12. Dr. Krimsky said he asked 
that this be discaassed, as he wondered vAiether it might indicate that 
E. cx)li K-12 is surviving in nature. Drs. Levine, Canpbell and Nightin- 
gale all said that just because the Massaciiusetts nursery isolate has 20 
enzymes electrcphoretically identical to ^ cx)li K-12, c3oes not at all 
mean that it will resemble ^ coli K-12 in the parameters that are impor- 
tant for ^ coli K-12's lack of ability to colonize. It was agreed that 
the data on the 20 enzymes are "a small drcp in a large bucket;" very 
incxxrplete data towards establishing the similarity of the Massachusetts 
isolate to ^ cx>li K-12. Further it was pointed exit that the paper 
states the Massachusetts isolate differs in its bacteriophage sensitivi- 
ties frcxn E. cx>li K-12. 
V. REVISED GENETIC MANIPUIATION ADVISORY GROUP GUIDELINES 
Dr. Gottesnan began disexission of the United Kingdom's revised Genetic 
Manipulation Advisory Group ((MAG) guidelines for reexrobinant ENA experi- 
ments (tab 964). She said the British had instituted a system in vhich 
numbers are assigned for "access," "expression," and "damage." The num- 
bers are multiplied together to obtain a final figure vhich determines 
the recxxnmended physical containment level. She said the RAC applies 
similar principles vhen evaluating recommended containment, but in not 
as e;^)licit a form. (MAG, like the RAC, has been cielegating increased 
responsibility to local committees. She said she did not perceive any 
significant differences in approach between the U. S. and the.British 
situation, vhich wcxild carpel the RAC to take action. 
[ 36 ] 
