FEDERAL SECURITY AGENCY
PUBLIC HEALTH SERVICE

 

IN REPLYING, ADDRESS THE December 14, 1949

Communicable Disease Center
Enteric Bacteriology Laboratory
Chamblee, Georgia

Dr. Joshua Lederberg
Department of Genetics

The University of Wisconsin
Madison 6, Wisconsin

Dear Dr. Lederberg:

Thank you very much for your letter of December 7. It was regretted
that such a long delay occurred in forwarding a report on the E. coli
cultures which you sent to the laboratory. I can only say that con-
sidering the condition of the cultures and our lack of O serum for
Coli 1 that the delay was more or less unavoidable. It was rather
surprising to me to hear that you had not manipulated these cultures.
Their condition more or less approximated that of cultures which we
have received for study and which had been exposed to radioactive
substances. Incidentally, we have been able to observe little

change in cultures of the latter sort except that they seem to undergo
rough degeneration.

Our thoughts regarding phage typing of enteric organisms are not

that it could be used to replace serologic typing. Like you, we feel
that it may be of value in breaking serological types into epidemiologi-
cal entities. Problems in establishing a laboratory such as the one here
are so numerous that many of the subjects upon which we would like to

do intensive work are as yet untouched. Phage studies on various

species of enteric organisms are among those projects which await
development.

The third paragraph of your letter needs some discussion, I believe.
First, let me say that we do not consider S. pullorum and S. gallinarum
members of the same type. We consider these two organisms as perfectly
distinct forms and I agree with you that their nutritional requirements
are quite different. Also their action in fowls is usually quite
distinct.

I agree that the work of Hohn and Herrmann had much to recommend it.

It is unfortunate that they went completely overboard in drawing the
conclusions which they did. ‘We were able to confirm many of their
observations but we could not agree that the nutritional varieties were
associated with any particular host. I am taking the liberty of
forwarding an old bulletin in which some work which we did on

varieties of S. typhi-mrium is described. It may be that you

already have a reprint. If so, you can give this one to some

 
Dr. Joshua Lederberg
Madison 6, Wisconsin Dec. 14, 1949

interested person. I believe this subject is capable of further
development but we have not worked on it for some years.

Your remarks concerning the citrate medium are in entire accordance
with our thoughts on this subject. Recently Dr. Ewing and I have
talked at length about this matter. These discussions were provoked
by a paper published recently by W. B. Christensen of urea agar fame.
A reprint of this paper can be obtained by writing to Mr. Christensen
at the following address: Weld County Health Department, Greeley,
Colorado. Christensen has pointed out that if citrate is combined
with a source of nitrogen which can be utilized by the organisms that
citrate utilization divides the enteric bacteria in an entirely
different manner than does Simmons medium. For instance, the
Alkalescens and Dispar types no longer are citrate negative but
utilize citrate whereas the true dysentery organisms do not. ‘This
Seems to be a reflection of the close relationships existing

between Alkalescens and Dispar and the Coliform group.

I am particularly anxious to discuss with you your frequent observance
of bacteriophage:in Salmonella cultures. So far as I know at present
I will be at the next SAB meeting in Baltimore. I hope to see you
there and to discuss these matters.

For the Officer in Charge, Bacteriology Branch
Sincerely yours,

1? K? Baro,

Philip R. Edwards, Ph. D.
Bacteriologist-in-Charge
PRE: mg Enteric Bacteriology Laboratory