Recombinant DMA Advisory Committee - 2/4/91 
12, but that the information that really exists on it in regards to its relative pathogenesis 
is small since no human experiments have been done comparable to those with E. coli K- 
12. The strain has been used before and that nothing much has happened, although this 
does not mean the strain is not pathogenic. In fact, there have been repeated anecdotal 
reports of workers contracting enteric fever from ingestion of the strain. Dr. Schaechter 
said that while this strain is possibly debilitated, it is still not something he would want to 
swallow or have in the workplace environment. Therefore, it should be worked on with 
proper precautions. The difference between working on something at BLl versus BL2 
were not that great and should not impede the investigators in their work. 
Dr. Schaechter said that the use of rough strains which are further debilitated could 
constitute a reason to downgrade the containment, but that such strains are messy to 
work with; this would be a possible out for the investigator if there is a valid reason for 
working at a lower safety level. 
Dr. Schaechter was not in favor of the request and would like to leave S. typhimurium at 
the BL2 safety level. 
Dr. B. Murray said she agreed with Dr. Schaechter and that she would be hesitant to 
reclassify potentially pathogenic organisms and have people work with them with less 
concern for safety. She recommended that the organism be left at the BL2 level. 
Dr. Krogstad said that the articles which had been supplied by the investigator proposing 
the lowering of biosafety level were based on molecular and genetic studies not aimed at 
an examination of virulence and not addressing the fundamental question of why the 
level should be reduced. In light of the lack of evidence demonstrating a lack of 
virulence in human volunteers, he believed it inappropriate to downgrade the safety 
level. 
Dr. Krogstad moved that the committee recommend leaving the containment at the BL2 
level. Dr. Schaechter seconded the motion. There being no further discussion on the 
motion. Dr. McGarrity called for a vote. The motion passed by a vote of 13 in favor, 0 
opposed, and 1 abstention. 
Dr. McGarrity then called on Mr. Mannix to present the next agenda item. 
X. REPORT FROM THE PLANNING SUBCOMMITTEE IN CHARGE OF REVIEWING 
COMMENTS RECEIVED DURING THE REGIONAL HEARINGS CONDUCTED BY 
THE RECOMBINANT DNA ADVISORY COMMITTEE CONCERNING THE FUTURE 
ROLE OF THIS COMMITTEE: 
Mr. Mannix said that the report that he prepared (tab 1420a) was only a draft and that 
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