62 



Swine Erysipelas. 



a red blood corpuscle, Fig. 20). lu bacilli grown m cultures 

 rine Gram-positive granules niav l)e demonstrated winch are 

 considered by Fedorowitsch and by Rosenbacli to be lasting 

 forms (protospores). 



Staining. They stain readily with aqueous aniline dyes as well as 

 by Gram's method. 



Cultivation. The bacilli grow well on the ordinary 

 artificial media with the exception of potato. It is 

 aerobic as well as anaerobic and grows in cultures some- 

 times as long rods or curved threads. On gelatin plates 

 the cultures form whitish, cloudy, very fine flakes with 

 coarse granular centers, which spread out towards the 

 periphery, into a delicate thready meshwork. More 

 rarely they form bright shiny, branching small colonies, 

 whereas in stahs pinhead sized, white points develop in 

 2 to 8 days which later fuse into grayish-white, cloudy 

 colonies, from which fine horizontal radiating branches 

 run in all directions of the gelatin (test tube-brush 

 shape. Fig. 21). On agar and on blood serum the 



Mcillus forms very fine 

 punctiform. dew-drop- 

 like colonies. Bouillon 

 is made slightly cloudy, 

 while later a fine, flaky 

 sediment forms on the 

 bottom of the tube. 



Fig. 21. Gela- 

 tin stab culture 

 of s w 1 n e ery- 

 sipelas bacilli. 



Fig. 20. Bacilli of swine erj/sipelaf 

 Smear prepared from blooil of a 



hot! 



Gram-eosin staining 



Tenacity. The ery- 

 sipelas bacilli manifest con- 

 siderable resistance towards 

 harmful influences, which 

 they probably owe to a wax- 

 like capsule (Schiitz &: 

 Voges). Drying kills them 

 only gradually as they re- 

 main alive when sub.iected 

 to a temperature of 37°C 

 for 31, and to direct sun- 

 light for 12 days (Sirena &: Alessi). Heating to 70 °C. destroys them in about 5 

 minutes. Pieces of meat not over 15 cm. thick require 2'^^ hours boiling for a 

 complete sterilization (Stadie). Putrefaction does not destroy the bacilli in meat in 

 4 months (Stadie). Salting and pickling destroys them very slowly; pieces of meat 

 and bacon may contain the virulent bacilli after lying in pickle for 170 days, and in 

 a mixture of salt and saltpeter for 30 days, while in smoked ham virulent bacilli were 

 found even after 3 months (Petri). On the other hand, continued smoking for 2 

 weeks or shorter periods of smoking once repeated destroys the virus of erysipelas 

 in pieces of pickled meat not over 2i^ kg. in weight (Stadie). 



Of the disinfectants the following are effective: Chlorate of lime (1%), hot 

 lye (1%), soda (5%), iron sulphate (3%), copper sulphate (%%), corrosive 

 sublimate (.1%), carbolic acid, creolin and lysol (Petri). 



Pathogenicity. Pure cultures inoculated subcutaneously 

 kill white and gray mice as well as pigeons in 2 to 4 days. In 

 rabbits the inoculation produces erysipelas-like reddening and 

 swelling at the point of inoculation, which is occasionally fol- 

 lowed in 5 to 6 days by a fatal general affection. In hogs an 

 inunction of virulent bouillon cultures into superficial wounds 



