MERCK INSTITUTE
FOR
THERAPEUTIC RESEARCH

RAHWAY, N. J.

April 6, 1954

Dr. Joshua Lederberg
University of Wisconsin
College of Agriculture
Department of Genetics
Madison 6, Wisconsin

Dear Doctor Lederberg:

I sent off the resistant Gratia and was
unfortunately interrupted and had to go to Chicago
before I had a chance to write to you about it. Upon
my return I found your letter of the 27th. The resis-
tant culture we are now dealing with is not the same
one reported on by Smith (J. Bact. 58, 761), the latter
having been lost. Actually this 1s about the third
separate isolate of a resistant from this strain.

Its Qo,(N)s are the following: Endogenous 8, pyruvate 54,
pyruvate + oxalacetate 96, and malate 42. This rep-
resents the resistant pattern and I naturally assumed

that this strain would show essentially the growth
pattern of the earlier. Your data shows that this is

not the case. I also set up a similar experiment in

a yeast-extract tryptone medium with three degrees of
aeration - i.e. 10 ml. in the usual tube, 10 ml. in

a 250 ml. flask, not shaken, and the same, shaken.

The growth at 18 hours was:

Without Glucose (Growth in pg. bact. N/m.)

Sensitive Resistant

Tube 36 356
Stationary 174 71
Shake 560 485

With 1% Glucose

Tube 150 42
Stationary 510 148
Sheke 690 680
Dr. Joshua Lederberg ~2- April 6, 1954

While there is a slight difference between the
resistant and sensitive strains at the low and intermediate
degrees of oxidation, there is essentially no difference
under conditions of high aeration which presumably were
the conditions used by Smith et al. It seems apparent
that we do not now have a strain showing these properties.
The question I suppose is whether we ever had one, for
if we claim they exist we ought to be able to demonstrate
the phenomenon. I feel sure that we had some once, but
am not inclined to go hunt for one again inasmuch as the
point has nothing to do with the mechanism of resistance
nor with the action of streptomycin, which is the point
of interest to me.

Sincerely yours,

WWU : VMF me - Umbreit