PYOGENIC BACTERIA. 



385 



to De Simone, a temperature of 39.5 to 41 C. maintained for two 

 days is fatal to this micrococcus. 



Manfredi and Traversa have injected filtered cultures into frogs, 

 guinea-pigs, and rabbits for the purpose of ascertaining if any solu- 

 ble toxic substance is produced during the growth of Streptococcus 

 pyogenes. They report that in some cases convulsions and in others 

 paralysis resulted from these injections. 



Von Lingelsheim has (1891) reported the following results 

 obtained in an extended series of experiments made to determine 

 the germicidal power of various chemical agents as tested upon 

 this microorganism time of exposure two hours : Hydrochloric acid 

 1 : 250, sulphuric acid 1 : 250, caustic soda 1 : 130, ammonia 1 : 25, 

 mercuric chloride 1 : 2,500, sulphate of copper 1 : 200, chloride of 

 iron 1 : 500, terchloride of iodine 1 : 750, peroxide of hydrogen 1 : 50, 

 carbolic acid 1 : 300, cresol 1 : 250, lysol 1 : 300, creolin 1 : 130, naph- 

 thylamin 1 : 125, malachite green 1 : 3,000, pyoktanin 1 : 700. 



FIG. 84. Section from margin of an erysipelatous inflammation, showing streptococci in 

 lymph spaces. From a photograph by Koch, x 900. 



Pathogenesis. When inoculated into the cornea of rabbits 

 Streptococcus pyogenes gives rise to keratitis. Inoculations into the 

 ear of the same animal usually give rise to a localized erysipelatous 

 inflammation accompanied by an elevation of temperature in the in- 

 oculated ear ; at the end of thirty-six to forty-eight hours the in- 

 flamed area, which has well-defined margins and a bright-red color, 

 extends from the point of inoculation along the course of the veins to 

 the root of the ear. This appearance passes away in the course of a 

 few days and the animal recovers. Subcutaneous injections into mice 

 or rabbits are usually without result, and the last-named animal also 

 withstands injections of considerable quantities into the general cir- 

 culation through a vein. When, however, the animal has previously 

 been weakened by the injection of toxic substances the streptococcus 

 may multiply in its body and cause its death (Fliigge). 



Fehleisen has inoculated cultures, obtained in the first instance 

 from the skin of patients with erysipelas, into patients in hospital 

 suffering from lupus and carcinoma, and has obtained positive re- 

 sults, a typical erysipelatous inflammation having developed 

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