PUBLIC HEALTH LABORATORY SERVICE
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Central Enteric Reference Laboratory and
£3 Bureau,

  

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Telephone: COLINDALE 7041 (8 lines) :

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23rd October, 1953.
Dear Dr. Lederberg, ,

Thank you for your letter of the 12th October.

(1) I was very glad to read in paragraph 2 of your letter the lucid

- —-i-diseription of the transduction process, split_into two phases, namely,
the initial fragmentation and the subsequent adventitious carriage of the ~
hereditary substance. In the last sentence of paragraph 2 you have
contrasted this process with the role of bacteriophage in phage type
determination where, as yeu put it, “infection with phage is not merely
a@ necessary but also a sufficient condition of the alteration™®. I would
like to draw your attention to the fact that the second half of the sentence
I have quoted is based on a mistake. Already in the preliminary peper in
Nature, 167, 603, 1951, it was show that treatment with the same phage
(£2) of five different typhoid type strains produced in each instance a
different Vi-phage type. Meanwhile, you may have read the full paper in
the Journal of General Microbiology, 9, 65, 1953 (August), which contains
further evidence to show that the latent phages which we were able to
demonstrate are not the sole factor in determination of the phage type of
the organism,

Now, I hope you will not mind my asking the simple question whether
it has been show beyond doubt in transduction experiments that bacteriophage
is really necessary for the ‘adventitious carriage! of the hereditary
material, Has it been shown conclusively that lysates heated to, say,
80°C. are no longer active in transduction? Has it been shown to your
satisfaction that fragmentation of the donor ofganisms by other techniques
(without the use of bacteriophage) does not yield equally active transducing
material? It may be you have answered these questions long ago, bat they
occurred to me as soon as I examined Créz6's cultures and convinced myself
that some of his claims were correct,

(2) Thank you for the information contained in paragraph 4 of your
letter. The transfer of the typhoid H antigen d to a Salm.paratypii B
strain is certainly a spectacular achievement, although I would like to
remind you of what I mentioned in my letter of the 2nd April, 1953 [on page 2,
item 3 (H antigens) J.

(3) I wonder whether you have laid down, for the benefit of your pupils,
some rules for distinguishing between 'transduction' and '? induction!

(? restoration or selection) of antigenic properties? In paragraph 4 you
wrote of transduction of motility to O 901 and transfer of d to Salm.
paratyphi B, both by phage little k. It seems to me advisable to lay down
some rules for distinguishing between transfer of theterologous' antigens
and redoration of the lost property to synthesize a "homologous! antigen,
Otherwise, I am afraid, one or other of your pupils may soon produce new
pitfalls in addition to those already besetting Salmmella serology and

phage typing.

(4) Re paragraph 2 on page 2 of your letter. - With regard to possible
interference of the TVi antigen with absorption of O phage, you certainly
know the paper by Nicolle et al., Ann.Inst.Past., 1953, 84, page 27,
Nevertheless, it is true that typhoid cultures possessing maximal amowmts
of the TVi antigen are readily lysed by O phages. I would suspect
interference not oly with absorption, at the surface, but also with the
synthesis of H antigen at the locus responsible for the development of
flagella which, of course, must be very close to that responsible for the
synthesis of the Vi antigen.

//
the /

(5) Agglutination by acriflavine. - I am afraid I do not know of any
work, published or unpublished, relating to Sertic! claim regarding
"non-specific" and "specific" H phases (C.R. Soc.Biol. 123: 951, 1936).
However, I would refer you to my letter dated 26th November, 1951, when I
sent you the reprint of an old paper by one of my previous co-workers,

W. Hirsch, which deals with a source of error in the acriflavine test
that is not generally know. As I mentioned at the time of sending the
reprint, it is possible that similer sources of error may be operating

in other Salmonelle species and in Gram nesative organisms generally,
which possess antigens of the type of/Vi antigen of Salm.typhi.

In addition, it was also shown in that paper (J.Path. & Bact., 1937,
44, 349) that saline washings from sterile agar slopes, containing agar in
colloidal form, are also flocculated by trypaflavine and modify the reaction
between the bacteria and trypaflavine. It may therefore be advisable to
look for similar interactions by some constituents of the particular broth
or agar medium employed.

(6) Referring to your remark about the possibilities of chemical
studies, following a visit by C. Weibull, I wonder what you meant by
"the two sets of factors"? Did you refer to the different protein
components of the various H antigens contained in the flagella, or did
you think of the chemical substance, or substances, that form the
transducing genetic material?

(7) Another paper by Hirsch that is probably unknown to you but may

be of interest is the following: "A new bacterial varient: the non-motile
H form", J.Hyg. Camb., 1947, 45, 41%. You will see that this paper dealt
with a hypothetical genetic fector responsible for the function or the
development of the motor centre of the flagella.

I hope the two envelopes containing the old reprints have by now
arrived safely.

With kind regards,

Yours sincerely,

Dr. J. Lederberg,
Department of Genetics,
University of Wisconsin,
College of Agriculture,
Agricultural Hall,
Madison 6, Wisconsin.