Professor Joshua Lederberg
Department of Genetics
University of Wisconsin
Madison ,

Dear Professor Lederberg,

I must ask you first to excuse me for addressing
you in such abrupt manner. I know that it is most imn-—
pertinent to demand advice to someone who is not wil- 3
ling to give it,but as I am badly in need I trespassed
this elementary rule and I am writing you.

I am a relatively young worker in the. field of
microbial variability.In the course of a work: on re-
combination in Serratia marcescens I was put in the
awkward situation to decide whether adaptation can co-
exist with mutation-selection in the teritory of drug
resistance.The number of those wao believe that drug
resistance in bacteria is due to progressive adaptation
is ratner small.As you know tney are crowded mainly in
Cambridge,England,under the banner of Sir Cyril Hinshel-
wood and are waging a phony war to their over-there and _
over-nere colleagues.They issued a book summing up their.
collective effort on adaptation in bacteria/Cambridge,1953/.
Iread this book in an excellent russian translation and
Ifound that tnere is something in it.I was thus obliged

‘to decide in my mind,because indecision in our particular

field leads to error and error to disaster.

I tried to devise an experimental system which would
leave but little room for doubt.It was my desire to,attack
diwetly the problem as I did hot want to prove the reality
of mutation but to prove or disprove the existance of in- “
duction of antibiotic-resistance. In this scope I looked
for your replica-plating method/J.Bact.1952,63,399/but as
RYAN et al. showed/J.Bact.1955,69,552/resistant clones may
spring on the top sensitive mother colonies I felt that the
velveteen stamp could carry secondary clones and thus give
a false argument to adaptation.Finally I choosed the antibi-
otic-gradient plate of BRYSON & SZYBALSKI /Science 1952,116,
45/ and the experiment was devised in tne following manner:

On a streptomycin-gradient plate /the highest concentration-

joo gamma/ I laid some cellophane triangles/grossly isoscels,
catheta 1.5 cm long/. Tuese triangles’ were laid on the drug-
free zone of the plate and seeded with one cell of Serratia
marcescens strain T/initial resitance to dihydrostreptomycin
RAFPA:3.3 gamma per ml/. After the colony has developped/18
nrs at 22°C/tne triangle was pulled.gradually accross the pla-

te to the antipiotic-full margin.This was done in five days.
Wnoen the drug-full margin was reached,tne triangles were re-

movea from the plate and the colonies separated from their cel-

lopuane support by stirring in a lo ml vroth containing test
tube.Adequate dilutions were made and plated for viable count
and streptomycin-resistance.Tue results indicated that the vast
majority of germs were killed by tne gradual contact with the

fe

\

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antibiotic and only ten or so cells escaped this fate
/ten in a billion in tne control/.It must be noted that
these cells rémained streptomycin-sensitive. © -

low,why do I seek your advice? May I interpret

tnese results as indicating that direct induction of an-

tibiotic-resistance does not exist: and all the brilliant
ratiocinations of the cambridgians are but blah-blah-blah?
Prior to the experiments I believed that my system will
radically decide in the case mutation versus adaptation.
There are already strong proofs accumulated against drug-
adaptation,may I consider my experiments as such a proof? .

I am most anxious to read your reply and begging
you again to excuse me for my abrupteness I remain

Sincerely yours,

Eugene Is Altescu M.D.
25.1V.1958 ~ . Wil

Laboratory Division
Dobrita Sanitarium
Tg Jiu
Romania

E.A./n.r.