1.) Organisms can be isolated from the blood of many
cases of subacute infective endocarditis but not from all.
2.) The organism most commonly isolated is a streptococcus
of non-haemolytic type.
3.) Cultures made from the blood during the last few
days of life may reveal organisms which have entered the
blood stream as part of a terminal invasion.
4.) Pneumococci and other pyogenic organisms isolated
from these cases are most frequently terminal invaders.
5.) Cultures made after death from the blood are unreliable
as a means of studying diseases due to streptococci
unless the observations are adequately controlled, as these
organisms occur very commonly as terminal or agonal invaders
of the blood stream.
6.) Failure to isolate streptococci from the blood in
cases of this disease has not been due to defective technique.
7.) The technique of blood culture has been studied experimentally.
Trypsinized media appear to be the best but
satisfactory results can be obtained with media containing
sodium citrate in a concentration of 0.2 per cent.
8.) The course of the septicaemia in this disease has
been studied quantitatively. The number of organisms is
usually small and the increase in numbers is slow and irregular.
9.) The serum of the patient contains agglutinins for
the organism producing the disease.
10.) The blood of a patient with infective endocarditis
can sterilize itself in vitro.
11.) The bacteria isolated from cases of this disease do
not form a homogeneous group.
12.) There is evidence that the bacteria isolated are not
in the same condition as those in a laboratory culture, but
that they are less capable of active growth.
13.) Delay in growth in blood cultures is chiefly dependent
upon the peculiarities of the organism present in the
14.) Experimental production of endocarditis in rabbits
is irregular and uncertain.
15.) Details of the progress of the septicaemia and production
of antibodies in the experimental animal resemble
closely those in the human disease.
16.) No evidence has been obtained of the existence of
any property of elective localization in the organisms isolated
from the human or the experimental disease.
17.) Experiments are recorded on the production of endocarditis
by the inoculation of pneumococci into immunized
18.) In most of the cases of infective endocarditis with
a negative blood culture bacteria can be demonstrated in the
vegetation but they appear to be in a degenerate condition.
19.) Attention is drawn to the resemblance between the
lesions in the valves in this disease and that in the submiliary
nodule in rheumatic fever.
20.) Submiliary nodules have not been found in the heart
muscle of cases of subacute infective endocarditis.
21.) Attempts at specific therapy by means of a specially
prepared serum and by means of transfusion of blood
from an immunized donor have not produced any beneficial
effect in the cases in which they have been tried.
22.) The significance of these findings in relation
to certain features of the disease is discussed.