REPORT OF THE KING INSTITUTE, GUINDY

7

the manufacture of stock vaccines new strains are substituted for old from time to
time, but what we lay most stress on is that the strains used should be the smooth
colony strains described by Arkwright which appear to have most antigenic
power. Cholera vaccine is made from six different smooth colony strains. T.A.B.
vaccine is made from six strains of typhoid, three of Para. (A) and three of
Para. (B).

        5. Improvement in media.—We grow cholera vibrios on Douglas agar lining
brandy bottles. At one time during the rush we were handling 120 bottles a day
which meant a great deal of work both in media and vaccine making.
Accordingly we experimented with the preparation of media to try and find a
medium that would give a better growth and so entail less work in preparation
and handling. The media we now use is Douglas agar with two modifications.
Firstly, the clearing of the Douglas broth is done by decanting and not by
filtration as for hormone media. Secondly, the medium is only once autoclaved;
the required quantity of chopped agar is put into the bottle, the Douglas
broth added and then the bottles are autoclaved. Solution of the agar takes
place during the autoclaving. This medium is cloudy, and so of no use for
diagnostic growths, but grows cholera vibrios almost twice as luxuriantly as the
ordinary Douglas agar we previously used. Of the officers concerned Dr. Martin
then in charge of the section, is to be particularly commended for the success of
the second important modification.

        6.Impronement in loading technique.—As in most other laboratories in
India Maynard’s apparatus is used to fill ampoules. By this method it is impos–
sible to prevent a certain amount of splintering of glass stems taking place at the
time of fracture. This results in small glass particles being drawn into some
ampoules. I found that in addition to the large particles which are harmless
because they cannot pass through a hypodermic needle, finer particles were also
present which could pass through a hypodermic needle. Accordingly it is import–
ant to avoid having glass particles in the ampoules as issued. This is now done
by ensuring that all glass particles fall to the bottom of the stem after the first
sealing. The second sealing is done above the deposit so that finally the sealed
ampoule as issued contains no glass particles.

        7. Efficacy of vaccines .—There has been no controlled test of cholera vaccine
in the field this year, but judging from the reports of some Health Officers who
claim that they stopped epidemics of cholera by extensively using vaccine, it
would appear that cholera vaccine continued to give good protection. This
benefit is, in a way, possibly a danger, for it may lead to less attention being paid
to the prevention of the disease by good sanitation.

        8. Sera for human use.Details are given in Table IX. The amount pur–
chased and issued has continued to increase. This was particularly the case with
anti-tetanic, anti-streptococcic, and anti–dysenteric sera. The cost this year was
Rs. 28,758 which is Rs. 10,000 less than last year although more serum was
bought. The saving is mainly due to the Lister Institute, London, being good
enough to grant a discount on these Government orders on my representation.

        9. Veterinary sera.—The work of distribution falls on this section and has
been described in Part I-D. Details are given in Table X.

(C) CLINICAL BACTERIOLOGY.

        1. Charge of work .—Civil Surgeon T. Sitapathi Ayyar, L.M.S., was in charge
of the section throughout the year and has helped to write this portion of the
report.

        2. Autogenous vaccines—Table VII, third column.—The total is less than
last year, because the General Hospital, Madras, now usually makes its own
autogenous vaccines. As usual, very few returns on the results of treatment
were received. The few that were received are analysed in Table VIII.

        3. Miscellaneous supplies—Table XI.—The Institute continued to supply
hospitals with various media for cultures and sterile solutions of drugs for
injection.