ERYSIPELOTHRIX RHU8I0PATHIM 401 



filiform growth extending to the bottom of the tube. Usually lateral outgrowths 

 occur ; these may be ill-defined, looking like snow-flakes, nebulae, or the con- 

 ventional bursting bomb ; or they may be definite branches producing a lamp- 

 brush appearance. The outgrowths may extend for a distance of only 2 or 3 

 mm. from the stab, or they may reach the sides of the tube. The smooth form 

 tends to remain restricted to the line of inoculation, while the rough form grows 

 out lateraUy. No hquefaction. The lamp-brush form may not be obtained tiU 

 after 2 or 3 subcultures in gelatin. 

 Broth.— 24: hours, 37 ° C. Smooth form. Slight uniform turbidity with very slight powdery 

 deposit disintegrating on shaking. After a few days the broth may clear, and a 

 viscous deposit become evident. Rough form. Little or no turbidity. Flocculi 

 of varying size or tangled-hair-like masses of growth appear, and settle on the 

 sides or bottom of the tube ; they are difficult to disintegrate by shaking. 

 Loeffler's Serum.— 1 days, 37° C. Very poor, confluent, sMghtly raised, colourless growth, 



sUghtly better than on agar. 

 MacConkey's Agar. — No growth. 

 Potato. — No visible growth. 

 Glucose Agar Shake.— Yery tiny colonies throughout medium ; on first isolation there 



may be a band growth just below surface. 

 Resistance.— In broth cultures the bacilU are killed by 

 moist heat at 55° C. in 15 minutes. In meat they 

 are highly resistant to salting, pickling and smoking, 

 surviving for 1 to 3 months ; they are likewise 

 resistant to putrefaction, remaining alive and vir- 

 ulent for months in putrefying buried cadavers. 

 Apparently succumb readily to drying, provided 

 this is complete. 

 Metoiofew.— Microaerophilic, but will grow under both 

 aerobic and anaerobic conditions. Optimum tem- 

 perature for growth is 30° C. ; grows between Yiq. &1 .—Erysipelothrix 

 about 15° and 44° C. Growth favoured by glucose rhusiopathia}. 

 and slightly by blood. Haemolysis occurs round Smooth form. Surface col- 

 deep colonies in 10 per cent, horse blood agar ouies on agar, 24 hours, 



, ^ ^ 37'= C. { X 8). 



y)lates. 



Biochemical— Sugar reactions are variable. Usually forms 



acid in dextrose and lactose, not in maltose, mannose, rhamnose, mannitol, 

 sucrose, dextrin, or salicin. L.M. no change or very slight acid. Indole negative. 

 M.R. negative. V.P. negative. Nitrates slight reduction. Catalase ±. M.K. 

 reduction negative. NHg negative. EgS ±. . . ii 



Antigenic Structure.-Eyidence of two antigenic types, each possessmg a heat-stabie 

 specific antigen, and two heat-labile antigens that are present m different pro- 

 portions in the two groups and are responsible for cross-agglutination. 



Pathogenicity.-Causes swine erysipelas in swine, and erysipeloid in man. Experimentally 

 it is pathogenic for mice, pigeons, and rabbits, but not for guinea-pigs. A non-tatal 

 dose inoculated into rabbits gives rise to a circulating monocytosis. Virulence 

 for swine is said to fall on artificial cultivation. No exotoxin is produced. 



Erysipelothrix monocytogenes 



Synonyms.-Bact. monocytogenes Murray, Webb and Swann ; Listerelki monocytogenes 



Isolation.-Bj Murray, Webb and Swann (1926) from rabbits suffering from a natural 



disease. 

 HaftitoL— Widespread animal parasite. 



