SCHIZOPHYTA SCHIZOMYCETES 171 



Poisonous properties. Not fully studied, but probably the same as those 

 of the next organism, Streptococcus pyogenes. 

 Immunity. Not known. 



Streptococcus pyogenes, Rosenbach. (Streptococcus erysipelatos, Fehleisen) 



Disease produced. This organism in various forms of inflammation and 

 septic inflammation in general, sometimes alone, sometimes associated with 



Micrococcus pyogenes albus, and aureus. Its speci- 

 fic cause, in many instances of septicemia, pyemia, 

 phlegmon, abscesses, boils, erysipelas, ulcerative en- 

 docarditis, periostitis, otitis, meningitis, pneumonia, 

 lymphangitis, bronchitis, inflammation of the serous 

 membranes, as pericarditis, pleuritis, peritonitis arth- 

 itis, enteritis, endometritis, tonsillitis, salpingitis, has 

 Fig. 28. Pus organism.becn held by some authors to cause rheumatic fevers 



Streptococcus pyogenes. In TJUUI 11 ,1 * 



chains, with pus cells x 800. Af-and also scarlet fever. Probably many so-called ter- 

 minal infections are produced by this organism. 



Pathogenesis. The organism is one of the pyogenic forms reacting much 

 as the Micrococcus pyogenes, as has been described. 



Poisonous properties. In many strains of Streptococcus pyogenes, there 

 is present an endotoxin. This is little understood, however, at the present 

 time. It is found that this endotoxin varies greatly ; in some cases none at all 

 being found in virulent types. It is susceptible to heat; organisms killed by 

 chloroform being more poisonous than those killed by heat. Virulent streptococ- 

 ci also produce an hemolytic toxin called streptocolysin. This is a true toxin. 

 The blood in fatal cases of streptococcic septicemia is often laked. The toxin 

 is destroyed at a temperature of 70 for two hours and by peptic digestion. 

 Substances which kill the leucocytes are also present in certain strains and inhibit 

 phagocytosis. It is very probable that the pathogenic character of this organ- 

 ism is not entirely explained by its known toxic properties. 



Immunity. Immunity against infection of streptococcus is probably due 

 largely to the presence of opsonins in the blood, and the consequent activity of 

 the phagocytes. Sera of animals which have been immunized by inoculation of 

 non-virulent or killed cultures seems to have some protective effect. Such has 

 not come into general use, however. Agglutinins are produced for most strains. 



BACTERIACEAE 



Bacillus suipcstifer, Salmon & Smith 



Disease produced. Hog cholera. Probably not the primary cause, but as- 

 sociated with some unknown ultra-microscopic organism. 



Animals infected. Swine. 



Animals susceptible. Rabbits. 



Pathogenesis. Post mortem examination reveals numerous petechiae, ecchy- 

 moses, and extravasations of blood into various tissues. This latter is par- 

 ticularly evident beneath the serous membranes. The spleen is enlarged, soft, 

 and engorged. In subacute cases, large intestinal ulcers are formed. 



Poisonous properties. Novy gave the name susotoxin to a poison base 

 which he discovered in pure cultures. This is probably not a specific poison 

 of the organism, certainly not a toxic. 



