90 SPECIAL BACTERIOLOGY 



THE STREPTOCOCCI OF ERYSIPELAS. 



The presence of streptococci in erysipelatous inflammations of the 

 skin was first observed by Koch. Fehleisen cultivated the cocci 

 artificially, and proved their pathogenic properties. According to 

 the above authorities they are more numerous upon the margins of 

 the erysipelatous area, and may even be seen in the lymph channels 

 a little beyond the red margin which marks the line of progress of 

 the infection. 



Microscopical Appearances. Micrococci arranged in chains, 

 consisting of either a few or many individual cocci. 



Motility. Non-motile. 



Staining Reactions. Any of the watery solutions of the aniline 

 dyes can be used. It is also stained by the Gram and Cladius 

 methods. 



Biological Characters 



On Gelatine Plates small dots like greyish-white colonies form, which 

 appear rnacroscopically opaque and coarse-grained, and never attain a 

 very great circumference. 



In Gelatine Stab Cultures small white round colonies form along the 

 inoculation track. 



On Agar Plates kept at incubator temperature point-like colonies 

 develop which do not attain any great size. 



In Stroke Cultures on Nutrient Gelatine or Agar small round transparent 

 fine dew-drops develop along the inoculated part, which remain 

 isolated. 



In Bouillon the growth is better than in the solid media ; it forms a 

 ropy sediment, which, when the tube is shaken, rises in the fluid. 

 Microscopically examined, the sediment is found to consist of long chains. 

 (See Photomicrograph, Fig. 27.) 



On Potatoes they may grow, according to some authorities, but others 

 agree that no growth occurs. 



Patliogenesis. Rabbits inoculated in the ear exhibit an erysipe- 

 latous inflammation extending from the point of inoculation to the 

 head and neck. The temperature rises, and reaches its height in from 

 eight to ten days, ending in recovery. 



Fehleisen inoculated cultures obtained from the skin of patients 

 with erysipelas into patients suffering from lupus and carcinoma, and 

 has obtained positive results, a typical erysipelatous inflammation 

 having developed around the point of inoculation, after a period 

 of incubation of from fifteen to sixty hours. This was accom- 



