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for the color of the surface smear of Limburger (31-33).
Ultimately, the possible commercialization of the antibiotic
substance was turned over to Eli Lilly and Co. (55, 58).
Reports indicate that the work done by Grecz fulfilled his
thesis requirements at the Illinois Institute of Technology,
reflecting Dack's adjunct appointment as professorial lecturer
at that institution.
During this decade, Dack continued to work on S. aureus
and its enterotoxin. Some of these efforts involved Bergdoll
and Sugiyama, new members of the FRI who would go on to
become recognized leaders in the fields of enterotoxin and
botulinum research, respectively. Several reports outlined
efforts to purify enterotoxin, produce antibodies against
it, and develop assays to assess it (2, 51, 52). Sugiyama et
al. (49) reported liver damage and liver enzyme release
following ingestion of enterotoxin by macaques.
A symposium on Salmonella (55th Annual Meeting of the
American Society for Microbiology, 1955), organized by
Dack on behalf of the FRI, provided a detailed analysis of
methods for isolating Salmonella from contaminated food.
Current researchers in this field will not be surprised to
learn that this study concluded that enrichment and several
selective media were needed to ensure isolation of Salmonella
when low cell numbers were present in the food (11).
That same article included data documenting the relatively
common contamination of pork and raw sausage with
Salmonella (11).
The difficulties with and value of coliform detection from
various food products versus the actual human risk were
thoughtfully considered in a review article in the American
Journal of Public Health (10). In a separate concise review
article, Dack discussed the possibility that postoperative
use of antibiotics could favor the survival and growth of enterotoxin-producing
S. aureus in the gut that would lead to
diarrhea and Pseudomembranous colitis (53). The potential
adverse effects of enamel coating of food cans were investigated,
and discounted, in a study by Ives and Dack (37).
6. UNIVERSITY OF CHICAGO, 1960-1969
By the 1960s, Dack was widely recognized as a leading authority
on microbiological food safety (Fig. 5). A reflection of
Dack's visibility and stature in the field is found in his authorship
of a review article on the therapy of foodborne disease
in the Journal of the American Medical Association (12). As
he neared the end of his career at the University of Chicago,
Dack's laboratory focused on staphylococcal enterotoxin and
applied projects of concern to the food industry. Examples of
the former included an agar gel immunodiffusion method to
visualize enterotoxin production (50) and an ion exchange
method to partially purify enterotoxin (2). Examples of
the latter included demonstration of the inability of several
pathogens (Salmonella, Escherichia coli, and S. aureus) to grow
in a slurry of meat pot pies (26) and formation of botulinum
toxin in some cans of chocolate nut rolls (62) or canned
FIGURE 4. Dack working in his laboratory in 1958 (University of
Chicago Library, Special Collections Research Center).
cheese experimentally inoculated with spores of C. botulinum
(30, 34).
Earlier in his career, Dack described a foodborne disease
outbreak that, based on its course, was likely caused by some
viral agent (7). In 1962, he had firsthand experience with
what was likely a viral enteritis outbreak that, ironically,
occurred at the 1962 International Conference on Microbiological
Quality of Food. Because Dack was among those
afflicted, he managed to acquire clinical samples; however,
these failed to yield known bacterial or viral pathogens,
perhaps because the methods available at the time could not
identify norovirus (4).
6.1. RETIREMENT AND TRANSFER OF THE FRI
As Dack neared retirement in 1966, it became apparent
that the University of Chicago was not interested in
maintaining support for FRI (Fig. 6). This resulted in efforts
by several key individuals in the food industry to find a new
academic home for FRI. Ultimately, this led to the transfer
of FRI to the UW, where it was led by Dr. Mike Foster. These
efforts may have been facilitated by familiarity among Dack
and Foster, as well as other prominent UW-Madison faculty
members (Professors Ira Baldwin and E.B. Fred) from their
time at Fort Detrick during the war (60). The planning and
efforts that culminated in the successful transfer, and the
academic negotiations inherent in that process, could be the
topic of a separate article. It is curious that the University of
Chicago was not interested in continuing to provide a home
for FRI, which had a strong team of food microbiologists and
sustained evidence of interest in and financial support by the
food industry. Some might suggest the decision was largely
the result of lesser regard for applied versus basic science.
That may be at least partly true, although the circumstances
were likely more nuanced. A history of the department (then
called the Department of Microbiology) at the University
of Chicago (40) indicates that by the 1960s, its faculty felt
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