200 WOUND INFECTION AND PYOGENIC BACTERIA 



Resistance. The Streptococcus pyogenes generally dies quickly 

 in liquid cultures or when dried out on silk threads. When con- 

 tained in dry pus it sometimes remains alive for weeks and months, 

 particularly if the cocci have dried out slowly and are subsequently 

 kept at low temperatures and protected against light. They are 

 comparatively resistant against high temperatures, generally being 

 able to withstand heat of 60 G. for one hour and occasionally for 

 two hours; 70 to 75 C. acting for one hour, however, positively kills 

 them. Cold appears to have no effect. A number of antiseptics 

 have been tried by von Lingelsheim. He gives the following concen- 

 trations as killing Streptococcus pyogenes in fifteen minutes: 



Hydrochloric acid . / . . . . ". . , . to 150 



Sulphuric acid . . . . . . ',. . . . . to 150 



Ammonia . ; . . . . . to 15 



Corrosive sublimate . . . . . . , . . . to 1500 



Copper sulphate to 125 



Chloride of iron . . . . ... .... 1 to 350 



Carbolic acid . . . * . . . . ..... to 200 



Kresol . . . *. . . . . to 175 



Lysol ....*,..;. to 200 



Kreolin . . . . 1 to 80 



Vaccine Therapy. This appears to be valueless in the acute infec- 

 tions, but in slow chronic cases the bacterine treatment often leads to 

 good results. 



BACILLUS PYOCYANEUS. 



Occurrence and Pathogenesis. The Bacillus pyocyaneus was first 

 found in and isolated from green pus. It is, however, also very 

 common as a saprophyte in the outside world. It has been found in 

 sewage, manure, water, the intestinal contents of man and domestic 

 animals (particularly the hog), rooms and hospital wards, barns, 

 etc. It generally lives as a harmless commensale in the intestines 

 of man and animals, but it has been known in ill-nourished, weak 

 children to invade the organism from the intestine and in a few cases 

 to have led to a general septicemia and death. It is frequently the 

 cause of local suppurations, also of purulent middle-ear inflamma- 

 tions. It imparts a green color to the pus. The Bacillus pyocyaneus is 

 also found in pus in animals, but it is doubtful whether it alone can start 

 a suppurative inflammation in domestic animals. According to Baru- 

 chelli, injection of the Bacillus pyocyaneus into the peritoneal cavity 

 of a male guinea-pig occasionally produces a periorchitis which may 

 cause it to be confounded with the Bacillus mallei in Strauss' biologic 

 test for glanders (see Chapter XXVI on the Glanders Bacillus). 



Morphology and Staining Properties. The Bacillus pyocyaneus is 

 generally a small, slender bacillus, but it also occurs in larger, plumper 

 varieties and the measurements given by various authors are from 

 0.3 to 1 to 0.6 to 2 to 6 micra. It has rounded ends and often forms 

 short chains of a few individual bacilli; longer pseudofilaments are 

 rare. The bacillus is very actively motile and possesses a flagellum 



