6
dysentery serum. If a colony reacted, it was sub-cultured on agar. From agar,
tubes of glucose agar and litmus milk were inoculated in the first place, and if no
gas was produced in the former, and in the latter the production of alkali, after
a preliminary acid formation, without clotting, occurred, then it was grown in, the
various sugars. The indol reaction, and the effect of inoculation into the rabbit
was also determined. The morphological characters of the bacillus, motility,
etc., as well as its behaviour towards Gram's stain, were noted in each case. In
this way it was possible to determine exactly the variety of dysentery bacillus
under observation.
Each case of dysentery was examined a number of times for the Bacillus
dysent er i œ. I f p o s i t i v e , t h e e x a m i n a t i o n s w e r e c o n t i n u e d i n t o c o n v a l e s c e n c e ,
after the stools had become feculent. In, Appendix, Table I, the results of the
investigation of each positive case are given. From a study of these results it will
be observed that the excretion, of bacilli in the stool is intermittent, as in the case
of the Bacillus typhosus. When the blood and mucus ceased, and the stools became
feculent, the presence of the Bacillus dysenteriœw a s n o l o n g e r d e t e c t e d , a n d f o r
a time the patient would not be actively infective. There is not yet sufficient
evi dence to express a defi ni te opi ni on as to whether, i n a certai n percentage of
cases, the Bacillus dysenteriœc o n t i n u e s t o e x i s t i n i n c o m p l e t e l y h e a l e d i n t e s t i n a l
ulcers for long periods, to reappear in the stools again when the ulcers become
active. The cultivation of the blood in cases of bacillary dysentery has not
shown, the presence of the Bacillus dysenteriœ, s o t h a t i t i s i m p r o b a b l e t h a t a
certain number of dysentery cases can continue to harbour the bacillus in the bile
and biliary passages as occurs in enteric fever.
As the lower part of the large intestine is frequently involved in bacillary
dysentery the diagnosis might be aided considerably by an examination with the
sigmoidoscope, a swab might be taken directly from the affected part for culture.
It is possible that when bacteriological examination of the stool failed to demons
- t r a t e t h e p r e s e n c e o f t h eB
a c i l l u s d y s e n t e r i œ
, t h e n a t u r e o f t h e c a s e m i g h t b e
determined by cultivating the material removed by the swab. Further, the
characteristic naked eye appearance of the large gut in bacillary dysentery should
be revealed by means of the sigmoidoscope.
As regards the varieties of the Bacillus dysenteriœi t w i l l b e s e e n t h a t o u t o f
t he 13 cases i n whi ch i t was det ermi ned 4 (30. 8 per cent . ) were produced by B .
dysenteriœ( S h i g a ) , a n d t h e r e m a i n d e r w e r e c a u s e d b yB
. d y s e n t e r i œ
( F l e x n e r ) .
None of the cases of bacillary dysentery showed any indication of liver compli
- c a t i o n , e i t h e r h e p a t i t i s o r a b s c e s s . N o r d i dB
. d y s e n t e r i œ
o c c u r i n , t h e s t o o l s o f
cases of liver abscess, although a careful and repeated examination was made.
It is of importance to note that, in the cases under observation, when the
stools became feculent, the dysentery bacilli were not detected in them. It will