Recombinant DNA Advisory Committee - 10/7-8/91 
compromising condition. The anaerobic Actinomyces have not addressed the aerobic 
ones. The anaerobic organisms are considered to be normal flora although they certainly 
can cause infections. The interest really is in the aerobic Actinomyces. 
There was a discussion as to the extent the animal model criteria used by the various 
contributors to classify the pathogens presented in the table. 
Dr. Fleming noted that the other experts polled were not particularly concerned about 
animal models. Dr. Beaman, one of the consultants contacted about this issue, is an 
expert on Nocardia. He felt that animals should be used to test some of the Nocardia. 
However, many of them were pathogenic in man, whether or not they had ever been 
shown to be pathogenic in an animal model. 
Dr. Wivel thought that some confusion may arise from the fact that there are clinical 
reports of lesions in human patients in which any of a variety of organisms may be 
isolated from that lesion. The problem is that those organisms may be passenger agents 
which are not the cause of the lesion. Therefore, that would be placed in the "suspected" 
category unless it could be documented in an animal model. 
Dr. McNeil said that in the suspected group compiled by the CDC, they have identified 
human cases where there is clinical evidence to suggest the agent caused the infection. 
That group also contains reports about clinical isolates referred to CDC from various 
sources. These organisms are ubiquitous. They are acquired by both normal and 
immunocompromised hosts. The relative transmission is either by inoculation or, much 
more commonly, by inhalation. If people in industry are to grow these organisms up in 
large quantity, there may also be dose effects to consider. 
Dr. McGarrity said that perhaps it would be desirable to appoint an advisory group to 
bring this discussion to a conclusion. 
Dr. Schaechter asked where in the latest Classification of Etiological Agents do the 
Actinomycetes fall. Dr. McNeil said they are handled at a level between I and II, albeit 
in an experienced laboratory. Dr. Schaechter asked if they have been used in large-scale 
applications without any known ill effects. Dr. McNeil replied that it is his 
understanding, given a lack of reporting, that they have been used in large-scale 
applications without any known untoward effect. 
Dr. Haselkom suggested the NIH Guidelines require that one cannot do an experiment 
before demonstrating that the organism to be used is not pathogenic. Dr. Schaechter 
said it would not be easy to show the pathogenicity. Dr. Post said it is an overkill for an 
organism that has been used for decades. 
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Recombinant DNA Research, Volume 15 
