Sapt~~mber 25, 1952

Dr. P. R. Edwarda
Co.mmunioable Diseama Center
Box 185, Chmbles, Geergis

Beear T)r , Z1d.warC.s :

I am writing again to ask your help by way of craltures and sera
for our garbc0tS.O 3xperfmnts with Selmhslla.

Dr. Zihdsr, as y'cu my know, 16 now at the Rockefeller &utituta
with Schneider, where he nil.1 have iirt opportunity to extend the
studfee initiated here. lr, addition, f. am spending a faix part of
my mm f&ii3 with SLwcella. For several wsvaoks this mmer, we
hztd the ple~uurs of 3 visit from Dr. 4.A.3. Stooksr (of the London
!3chool of Qgiens) , and we worked cn ths transfer of motilitg from
H- forms to 0-f ems of the aame and different serotypes. As a rule,
this tramfar doss not alter the sxpeated %spsoifiaits of ths
bacteria. Thsre r~ac one rather compliaated exception I my already
have mentioned: an &ford derived from a zonophaeic (b) 3. paratyphi
B gavs mostly b-- H forms when trsated with ltFAft Erm 3. typhimurium,
but in a f sw instances, i-- H forma were obtained.  X have not bean
able to repeat the single incident whsn the lattm occurred as a sp&aneous
motile mutant (md am theref cre doubtful of nat) . The strain ia so stable
that wecobtained very few ~~otile m&~&~&itb very extmsivs tssts. On
the other hand it rssponds very hiauy indeed to the appropriate FA,
and thus sakes a very niae demonstration of transduction. I am still
planning on the distlussed visit for so- months hence, and hope to be
able to demonstrate this in person at that tims.

For the present, 3 would like to continue the reuombinstion of antigens
along the lines of the "hybrid" typhi x typhimriue) experiments. The
types paratyphi B, eastbourne, rsadiag,and onarimon would seem to form
a natural set of mutually oorsplementary reuombinants, and I thought
it might be of SORM interest to try to duplicate or reconstruct them
in ths 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 straiaa are "difficult", I would appre-
ciate it if you could serxiaas many as two or three independent isolatss
of the eastbomne, reading and enarimn, if they are available. Would it
be possible for us to ask for 510 ml. clean, undiluted sera b;1,2.. and
sh;l,S for flagUl.ar-immobilisations, aad a few ml. of typing reagents
for b, oh, snd 5. It my be necressary for us later to prepare more con-
centrated nonospecific sera for immobilization, but we can probably do
the necessary absorptions ourselves.     Sinaerelg,                        I_.-"-
                          Joshua bderberg