Bacilli Resembling the Typhoid Bacillus 627 



acid, which, formed late, eventually checks its further development. It does not 

 ferment saccharose. 



Indol. — No indol and no phenol are formed in the culture-media. 



Toxin. — In pure cultures of the hog-cholera bacillus Novy* found a poisonous 

 base with the probable composition Ci6H26N2, which he gave the provisional 

 name "susotoxin." In doses ofioo mg. the hydrochlorid of this base causes con- 

 vulsive tremors and death within one and one-half hours in white rats. He has 

 also obtained a poisonous protein of which 50 mg. were fatal for white rats, and 

 which immunized them against highly virulent hog-cholera organisms when 

 administered by repeated subcutaneous injection. 



De Schweinitzf has also separated a slightly poisonous base which he calls 

 "sucholotoxin," and a poisonous protein that crystallizes in white, translucent 

 plates when dried over sulphuric acid in vacuo, forms needle-like crystals with 

 platinic chlorid, and was classed among the albumoses. 



Pathogenesis. — The bacillus is disappointing in its effects upon hogs. When 

 it is subcutaneously or intravenously introduced into such animals or fed to them, 

 they sometimes show no signs of disease; sometimes show fever and depression, 

 but rarely sicken enough to die. Animals thus made ill do not communicate 

 hog cholera to others. 



Smith found that 0.75 cc. of a bouillon culture injected into the breast mus- 

 cles of pigeons would kiU them. 



In Smith's experiments one four-millionth of a cubic centimeter of a bouillon 

 culture injected subcutaneously into a rabbit was sufiScient to cause its death. 

 The temperature abruptly rises 2° to 3°C., and remains high until death. Sub- 

 cutaneous injection of larger quantities may kiU in five days. Injected intra- 

 venously in small doses the bacillus may kiU rabbits in forty-eight hours. 



Agglutination. — PitfieldJ found that after a single injection of a killed bouillon 

 culture of the bacillus into a horse, the serum, which originally had very slight 

 agglutinative power, showed a decided increase. If the horse be immunized to 

 large doses of such sterile cultures, the serum becomes so active that with a 

 dilution of i : 10,000 a typical agglutination occurs in sixty minutes. 



McClintock, Boxmeyer and Siffer§ found that the serum of normal hogs 

 agglutinates strains of ordinary hog-cholera bacilli in dilutions occasionally as 

 high as 1 1250 and consider reaction in a dilution of less than i :3oo without diag- 

 nostic value. 



Bacillus Icteroides (Sanarelli) 



General Characteristics. — An actively motile, flagellated, non-sporogenous, 

 non-liquefying, non-chromogenic, aerogenic, aerobic and optionally anaerobic, 

 pathogenic bacillus which stains by the ordinary method, but not by Gram's 

 method. It produces indol, but does not coagulate milk. 



Sanarelli regarded this bacillus as the specific organism of yellow fever. He 

 found it in II autopsies upon yellow fever cases, but always in association with 

 streptococci, colon bacilli, proteus, and other organisms. It is found in the 

 blood and tissues, and not in the gastro-intestinal tract, and isolation of the 

 organism was possible in only 58 per cent, of the cases, and only in rare instances 

 was accomplished during life. 



Distribution. — By suitable methods it can be found in the organs of yellow 

 fever cadavers, usually aggregated in small groups, in the capillaries of the liver, 

 kidneys, and other organs. The best method of demonstration is to keep a frag- 

 ment of liver, obtained from a body soon after death, in the incubator at 37°C._ for 

 twelve hours, and allow the bacteria to mviltiply in the tissue before examination. 



Morphology. — The bacillus presents nothing morphologically characteristic. 

 It is a small pleomorphous bacillus with rounded ends, usually joined in pairs. It 

 is 2 to 4 fi in length, and, as a rule, two or three times longer than broad. It is 

 actively motile and has flageUa. It does not form spores. 



Staining. — It stains by the usual methods, but not by Gram's method. 



"Medical News," 1900, p. 231. 

 "Medical News," 1900, p. 237. 

 "Microscopical Bulletin," 1897, p. 35- 

 It "Jour, of Infectious Diseases," March i, 1905, vol. 11, No. 2, p. 351- 



