DEPARTMENT OF BACTERIOLOGY AND IMMUNOLOGY
HARVARD MEDICAL SCHOOL
23 SHATTUCK STREET

BOSTON 15, MASSACHUSETTS

April 8, 1960

Dr. Joshua Lederberg
Department of Genetics
Stanford University
Medical School

Palo Alto, California

Dear Joshua:

Dr. George Ivanovics, Professor of Microbiology at the University
of Szeged in Hungary, is visiting here for a couple of months on a Rockefeller
Foundation Grant, and will be getting out West in May. He expects to be in
the San Francisco area from about the 18th through 2th. I've written Dr.
Raffel about this visit, suggesting that Dr. Ivanovics could give a very
interesting seminar on megacin, a bacteriocin from B, megaterium. I hope
you'll be able to see Ivanovics too; he's a very nice guy, and we've enjoyed
having him here.

Since I've become quite convinced that the primary site of action
of streptomycin is the cell membrane, with no detectable amounts of
streptomycin getting beyond the membrane until the cell has been damaged,
it seems to me that we have a reasonable starting place for re-attacking
the old problem of the mechanism of streptomycin dependentg. During his
brief stay here Dr. Ivanovics has been looking for evidence that deprival
of streptomycin might alter the permeability characteristics of a dependent
strain. In addition, our work with Anand indicated that streptomycin does
not get beyond the membrane in a resistant strain, and lead us to expect
that a resistant strain might be readily killed by streptomycin if some
other agent were used to make the cell leaky. Dr. Ivanovies has just
called my attention to a brief mention, in your paper with Saint-Claire,
of experiments that are very relevant to these problems. I wonder
whether you have this material available in any form that could be
readily lent me or summarized. I'm planning to push the streptomycin
problem with a couple of post-doctoral fellows who are arriving in
July, and I would hate to waste time going over ground that you have
already covered.

With best regards to you and Esther.

Sincerely,

wwe =
.

feeccee

Bernard D, Davis