September 25, 1952

Pr. P. R. Edwarde
Communicable Diseases Center
Box 185, Chamblee, Geergia

Dear Dr, "Edwards:

I am writing again to ask your help by way of cultures and sera
for our genetic s«perinents with Salmonella.

Dr. Zinder, as you any know, 1s now at the Rockefeller Institute
with Schneider, where he will have an opportunity to extend the
studiee initiatad here. In addition, I am spending a fair part of
my own tins with Salucnella. For several weeks this suamer, we
had the pleasure of a visit from Dr. 3.A.D. Stocker (of the London
School of Hygiene), and we worked cn the transfer of motility from
H~ forms to O-forms of the same and different serotypes. As a rule,
this transfer does not alter the expected H-specificity of the
bacteria. There was one rather complicated exception I may already
have mentioned: an O-formg derived from a monophasic (b) 3, paratyphi
B gave mostly b-—- H forms when treated with "FA" @rom S. typhimriua,
but in a few instances, i-- H forms were obtained. I have not been
able to repeat the single incident when the latter occurred as a spetaneous
motile mitant (and am therefore doubtful, of that). The strain is so stable
that wecobtained very few motile mitants with very exteasive tests. On
the other hand it responds very hiebay indeed to the appropriate FA,
and thus makes a very nice demonstration of transduction. I am still
planning on the discussed visit for some months hence, and hope to be
able to demonstrate this in person at that time.

For the present, I would like to continue the recombination of antigens
along the lines of the "hybrid" typhi x typhimuriug experiments. The
types paratyphi B, eastbourne, reading,and onarimon would seem to form
a natural set of mitually complementary recombinants, and I thought
it might be of some interest to try to duplicate or reconstruct then
in the laboratory. I have a satisfactory set of paratyphi B, and one
eastbourne from a doubtful lyophil vial, but must apply to you for the
others. As occasional individual strains are "difficult", I would appre~
ciate it if you could sendaas many as two or three independent isolates
of the eastbommne, reading and enarimon, if they are available. Would it
be possible for us to ask for 5-10 ml. clean, undiluted sera b;1,2.. and
oh31,5 for flaghllar—immobilizations, and a few ml. of typing reagents
for b, eh, and 5. It may be necessary for us later to prepare more con-
centrated monospecific sera for immobilization, but we can probably do
the necessary absorptions ourselves. Sincerely,

Joshua Lederberg