262 THE PYOGENIC COCCI 



to be rather marked in the average normal man, seems to depend 

 largely on the phagocytic activity of leukocytes in the last analysis; 

 and the efficiency of vaccines, particularly the autogenous vaccines, 

 in the treatment of furunculosis has focused attention sharply upon 

 the part played by opsonins in these infections. Generally speaking, 

 injections of killed cultures of staphylococci in graduated doses 

 beginning with one hundred millions and increasing to a thousand 

 millions or more at appropriate intervals exert a favorable influence on 

 the course of the infection. The efficiency of this vaccination (active 

 immunization) is attributed to the gradual development of specific 

 opsonins (bacteriotropins) which reenforce the action of normal 

 opsonins, whose activity is somewhat below normal. In practice 

 this is accomplished in the following manner : the organism is isolated 

 on agar slants in pure culture, washed off, after twenty-four hours' 

 incubation, in normal salt solution, thoroughly emulsified, and stan- 

 dardized so that each cubic centimeter contains the requisite number 

 of bacteria. They are killed either by heating to 80 C. for one hour, 

 or, better, by the addition of Oi5 per cent, carbolic acid, and incubation 

 at 37 C. for twenty-four hours. The sterility of the culture must be 

 demonstrated before it is used. This vaccine is inoculated subcutan- 

 eiously, with surgical precautions, using the dosage mentioned above 

 as a routine. The inoculations are repeated at intervals of from five 

 to eight days. The duration of the immunity induced by vaccination 

 is not known. Vaccines are less effective in pyemia and metastatic 

 staphylococcus infections than in the localized infections. 



The lessened lipase activity of the blood, manifested by a decreased 

 splitting of ethyl butyrate, is a frequent result of staphylococcus 

 invasion, according to Clerc; 1 according to V. Dungern, 2 the blood 

 serum from cases of extensive osteomyelitis is several times as inhib- 

 itory to the staphylococcus enzymes as is that of normal individuals. 



Antibodies. The cell substance of staphylococci does not appear 

 to be very poisonous to experimental animals, 3 and although an anti- 

 staphylolysin and an antileukocidin are relatively easily produced in 

 experimental animals, they do not appear to confer any consider- 

 able degree of immunity. Agglutinins do not appear to have been 

 demonstrated in the blood serum of man and animals suffering from 

 staphylococcal infections, but Kolb and Otto, and Proscher 4 claim 



1 Compt. rend. Soc. de biol., 1901, liii, 1131. 



2 Munchen. med. Wchnschr., 1898, xlv, 1040. 



3 Kruse, Allgemeine Mikrobiologie, Leipzig, 1910, p. 968. 



4 Cent. f. Bakt., 1903, xxxiv: quoted by Besson, Practical Bacteriology, 1913. 



