558 PATHOGENIC AEROBIC BACILLI 
BACILLUS OF PURPURA HAZ MORRHAGICA OF TIZZONI AND GIO- 
VANNINI. 
Obtained by Tizzoni and Giovannini (1889) from the blood of two children. 
who died of purpura hemorrhagica following impetigo. 
Morphology.—Bacilli with round ends, from 0.75 to 1.3 # long and 0.2 
to 0.4 x broad; often seen in pairs or in groups like streptococci. 
Stains with the usual aniline colors, but not by Gram’s method. 
Biological Characters.—An aérobie and facultative anaérobic, non- 
liquefying, non-motile bacillus. Spore formation not observed. Grows in 
the usual culture media at theroom temperature. Upon gelatin plates the 
colonies at first resemble those of Streptococcus pyogenes. Upon the surface 
small, opaque points are seen at the end of forty-eight hours, which at the 
end of four to five days develop into spherical, yellowish-gray colonies with 
irregular margins, surrounded by a growth resembling tufts of curly hair. 
Upon agar the growth is similar, but more rapid and of a pale color, often 
with a central nucleus surrounded by a. net-like marginal zone. Upon 
blood serum the growth is similar to that upon agar. Upon potato, at 37° 
C., a limited development occurs about the point of inoculation, which has 
a dark-yellow color. The cultures give off a very penetrating odor. 
Pathogenesis.—Pathogenic for dogs, rabbits, and guinea-pigs when in- 
jected subcutaneously. Not pathogenic for white mice or pigeons. The 
symptoms resulting from a subcutaneous injection are said to be fever, al- 
buminuria and, in some cases, anuria, hemorrhagic spots upon. the skin, 
convulsions ; death occurs in from one to three days. Atthe autopsy there 
are found cedema about the point of inoculation, hemorrhages in the skin and 
muscles, and sometimes in the internal organs and in serous cavities; the 
blood does not coagulate. The bacilli are found in the subcutaneous con- 
nective tissue, but not in the blood or in the various organs. Sections show 
coagulation necrosis of the liver cells and of the renal epithelium. 
BACILLUS OF PURPURA HMMORRHAGICA OF BABES. 
Obtained by Babes (1890) from the spleen and lungs of an individual who- 
died from purpura hzmorrhagica with symptoms of septicemia. Resembles 
the bacillus previously described by Tizzoni and Giovannini, and still more 
that of Kolb; but, according to Babes, differs in some respects from both of 
these, although they all belong evidently to the same group. 
Morphology.—Bacilli with rounded ends, oval or pear-shaped, about 0.3 
thick, surrounded by a narrow capsule. 
Stains with the aniline colors, but not deeply, and still less intensely by 
Gram’s method. 
Biological Characters.—An aérobic and facultative anaérobic, non-- 
liquefying, non-motile bacillus. Does not form spores. Grows in the usual 
culture media at the room temperature. In gelatin stick cultures, at the 
end of three days, a thin, transparent, irregular layer has developed upon 
the surface, and a whitish, punctate stripe along the line of inoculation. In 
agar stick cultures an abundant development occurs along the line of punc- 
ture, and at the end of three days the growth upon the surface consists of 
small, moist, transparent drops; later of larger, flat, shining, yellowish- 
white plaques which have ill-defined margins. Upon blood serum the de- 
velopment is somewhat more abundant in the form of small, white, moist 
colonies one to two millimetres broad. Upon potato, at the end of three 
days, moist, whitish drops with ill-defined margins. 
Pathogenesis.—Inoculations in the conjunctive of rabbits produce ecchy- 
moses of the conjunctiva. At the autopsy numerous hemorrhagic extrava- 
sations are found in all the organs, especially in the lungs and liver; the 
spleen is enlarged; the bacilli can be recovered in pure cultures from the 
various organs. Old cultures proved to have lost their virulence. Patho- 
genic for mice, which die from general infection in the course of a few days; 
