CHAPTER XLI. 

 STREPTOCOCCI HOMINIS. 



Introduction. 



Varieties of streptococci, p. 593. 

 Section I. Experimental inoculation, p. 594. 

 Section II. Morphology, p. 595. 



1. Microscopical appearance and staining reactions, p. 595. 2. Cultural charac- 

 teristics, p. 597. 

 Section III. Biological properties, p. 599. 



1. Vitality and virulence, p. 599. 2. Bio-chemical reactions, p. 600. Andrewes 

 and Herder's classification, p. 601. 3. Toxins, p. 602. Streptocolysin, p. 603. 

 4. Vaccination, p. 604. 5. Serum therapy, p. 605. A. Monovalent serums, p. 606. 

 B. Polyvalent serums, p. 608. 6. Agglutination, p. 609. 

 7. Bordet-Gengou reaction, p. 609. 

 Section IV. Detection and isolation of streptococci, p. 609. 



The streptococcus of Bonome, p. 610. 



STREPTOCOCCI were first described by Pasteur and Doleris who found them 

 originally in the blood of women suffering from puerperal fever. 



Streptococci as the primary cause of disease. Streptococci are the primary 

 cause of many inflammatory, suppurative and septicsemic processes. Thus 

 they are the cause of puerperal septicaemia (Pasteur and Doleris) and erysipelas 

 (Fehleisen) : they are a common cause of osteo-myelitis and of purulent 

 surgical affections and have also been found to be the primary infecting agent 

 in certain cases of each of the following among other diseases : phlebitis, 

 broncho-pneumonia, pleurisy, peritonitis, meningitis, endocarditis, salpingitis, 

 otitis, and dermatitis. 



In all pathological conditions of the throat of whatever nature streptococci 

 are to be found either as the primary cause of the lesion or as an associated 

 infection. 



[Acute rheumatism is attributed by some observers to infection with a 

 streptococcus (Beattie ; Poynton and Paine and others).] 



It is now generally conceded that streptococci are not the specific cause of 

 scarlet fever though these organisms are almost constantly present as secon- 

 dary infections. Weaver, for instance, found streptococci nearly always 

 present in the throat during an attack of scarlet fever. Hektoen, however, 

 only found streptococci in the blood in 12 out of 100 cases of scarlet fever 

 which he examined. 



Streptococci as secondary infections. As secondary infections streptococci are 

 not infrequently found complicating an already existing infective disease and under 

 these conditions are even more dangerous than when acting as primary infections. 



