, Streptococcus Pyogenes 313 



Tuberculous infections were not included. Of the 255 cases, 213 

 gave positive bacteriologic results. "The micro-organisms causing 

 the infections, 38 in all, were Streptococcus pyogenes, 16 cases; 

 Staphylococcus pyogenes aureus, 4 cases; Micrococcus lanceolatus, 

 6 cases; gas bacillus (Bacillus aerogenes capsulatus), three times 

 alone and twice combined with B. coli communis; the gonococcus, 

 anthrax bacillus; B. proteus, the last combined with B. coli; B. 

 coli alone; a peculiar capsulated bacillus, and an unidentified 

 coccus." 



It is interesting to observe in how many cases the streptococcus 

 was present. All the streptococci found may not have been Strepto- 

 coccus pyogenes, but for convenience in his statistics they were re- 

 garded as such. 



The presence of streptococci in the blood in scarlatina has been 

 observed in 30 cases by Crooke, by Frankel and Trendenburg, 

 Raskin, Leubarth, Kurth, and Babes. In 11 cases of scarlatina 

 studied by Wright* a general streptococcus infection occurred in 

 4, a penumococcus infection in i , and a mixed infection of pyogenic 

 cocci in i. 



Lemoinef found streptococci in the blood during life in 2 out of 

 33 cases of scarlet fever studied. Pearcef studied 17 cases of scarla- 

 tina and found streptococci in the heart's blood and liver in 4, in 

 the spleen in 2, in the kidney in 5 cases. In 2 of the cases Staphy- 

 lococcus pyogenes aureus was associated with the streptococcus. 



The streptococcus is the most common organism found in the 

 suppurative sequelse of scarlatina, frequently occurring alone; 

 sometimes with the staphylococci; sometimes with the pneumococci. 



Virulence. — Streptococci isolated from human beings vary greatly 

 in pathogenic action upon the laboratory experiment animals. In 

 many cases, although they have induced a fatal illness in human 

 beings, they are without effect upon the lower animals; in other 

 cases, although from a more simple lesion that recovered, they are 

 extremely fatal for the most susceptible animals, rabbits and mice. 

 Rats sometimes become ill when injected with virulent cultures in 

 large doses, but usually recover. Guinea-pigs, cats, and dogs are 

 but slightly susceptible even when the cultures are virulent. Large 

 animals, like sheep, goats, cattle, and horses, react very slightly 

 to large doses, but sometimes suffer from abscesses at the seat of 

 injection. Mice die in from one to four days from general infec- 

 tion. If the organisms are less virulent, they die in from four to 

 six days with edema and abscess formation at the site of inocula- 

 tion, and subsequent invasion of the body. All streptococci seem 

 to be most pathogenic for that species of animal from which they 

 ^ave been isolated. 



* "Boston Med. and Surg. Jour., "March 21, 1895. 



t "Bull, et M6m. Soc. d'H6p. de Paris," 1896, 3 s., xm. 



t "Jour. Boston Soc. of Med. Sci./' March, 1898. 



