EXPERIENCE WITH METHYLENE BLUE-EOSIN LAC- 
TOSE AGAR IN SEARCHING FOR BACILLUS 
DYSENTERIZ IN STOOLS 
By C. S. PANGANIBAN and O. ScHOsL * 
(From the Serum Section, Bureau of Science, Manila) 
In the absence of suitable enrichment and selective media the 
isolation of Bacillus dysenteriz from stools is handicapped by 
certain difficulties. It is true that in cases of acute bacillary 
dysentery the colonies of B. dysenterix that develop on the 
plates are at times numerous, and that practically no other 
colonies are found. On the other hand, experience teaches that 
even in a typical acute dysenteric stool the laboratory test fails 
to isolate B. dysenteriz. If amcebe be present in such a spec- 
imen, the clinician may easily be misguided and decide the case 
as amoebic dysentery. The clinical picture and the course of 
the disease may guide the clinician in the differentia] diagnosis 
of a particular dysentery case; but the clinical picture of either 
of the two forms of dysentery is surely not typical in every 
case, else the examination of stools for B. dysenteriz would not 
be so persistently insisted upon by clinicians as it usually is, 
and rightly so. 
The presence of amcebe in acute dysentery stools does not 
necessarily exclude bacillary dysentery. One must consider the 
comparatively high percentage of amcebe contact carriers. Fur- 
thermore, a superposed bacillary infection in a chronic case of ' 
amoebic dysentery is not so rare an occurrence as would appear 
at first thought. The theory advanced from some quarters that 
an attack of bacillary dysentery confers immunity and, therefore, 
if the patient gives history of previous attacks of dysentery it 
is amebic and not bacillary dysentery is even theoretically un- 
tenable. Granted that the previous attacks were due to amebic 
infection, this supposition does not prove that the present illness 
is not bacillary dysentery for the reason mentioned above. 
From these considerations it is clear that the bacteriological 
diagnosis of bacillary dysentery is highly desirable. Hence any 
improvement in the laboratory technic which tends to facilitate 
the detection of B. dysenterizx in stools will be welcomed by the 
laboratory worker as well as by the clinician, 
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