342 PATHOGENIC MICROORGANISMS 



Spontaneous streptococcus disease seems to occur among some of 

 the larger domestic animals. Thus, a contagious form of inflammation 

 of the respiratory passages of horses has been attributed to streptococcus 

 infection. 1 Among cattle these microorganisms have been found to 

 produce purulent inflammation of the udder and occasionally post- 

 partum uterine inflammation in cows. Among the smaller labora- 

 tory animals, occasional streptococcus infections may be observed in 

 rabbits. Recently an epidemic disease among white mice due to strep- 

 tococcus was studied by Kutscher.^ As a rule, however, streptococcus 

 disease is by far more rare among animals than it is among human beings. 



In man, a large variety of pathological processes may be caused by 

 streptococci and here again the nature of the infection, whether definitely 

 localized or generally distributed, depends upon the relationship existing 

 between the virulence of the incitant and the resistance of the subject. 



The first cultivation of streptococcus from human lesions was made 

 by Fehleisen,' who obtained them from cases of erysipelas. It was 

 long believed that the so-called Streptococcus erysipelatis was a 

 similar but essentially different species from the comimon Streptococcus 

 pyogenes. The production of erysipelas in animals with streptococci 

 from other sources, however, has shown definitely that the two groups 

 can not be separated.^ Superficial cutaneous infections are frequently 

 caused by streptococci and these in the milder cases may be similar 

 to the locahzed abscesses caused by staphylococci. In severe cases, 

 however, infection is followed by rapidly spreading edema, lymph- 

 angitis, and severe systemic manifestations with the development of a 

 grave cellulitis, often threatening life and requiring energetic surgical 

 interference. Invasion of the respiratory organs by streptococci is not 

 rare, and may lead to bronchitis, pneumonia, or empyema. They are 

 frequently present also as secondary invaders in pulmonary tubercu- 

 losis.^ Streptococcus infections of the lungs and pleura not infrequently 

 lead to pericardial involvement. 



Suppurations of bone may be caused by streptococci, and constitute 

 a severe form of osteomyelitis. Such lesions when occurring in the 

 mastoid bone are not infrequently secondary to streptococcus otitis and 

 may lead to a form of meningitis which is in most cases fatal. In the 



' Van de Velde, Monatsheft Bakt., Thierheilk., ii. 



2 Kutscher, Cent. f. Bakt., xlvi. 



' Fehleisen, loc. cit. 



' Marhaix, La Cellule, 1892; Petnischhy, Zeit. f. Hyg., xxiii. 



5 Cornet, "Die Tuberkulose," Wien, 1899. 



