502 PATHOGENIC AEROBIC BACILLI 



Morphology. Slightly curved bacilli with pointed ends; solitary or in 

 pairs, or in chains of four to eight elements. 



Biological Characters. An aerobic and facultative anaerobic, liquefy- 

 ing bacillus. Spore formation not observed. Grows in the usual culture 

 media at the room temperature. In gelatin plates large, spherical, opaque, 

 yellowish-brown colonies are formed. In gelatin stick cultures liquefaction 

 occurs in the upper part of the tube and gradually extends downward, the 

 liquefied gelatin being separated from the non-liquefied by a horizontal 

 plane. 



Pathogenesis. Small quantities of a pure culture injected into the abdo- 

 minal cavity of white mice proved fatal to these animals in from eighteen to 

 thirty hours. 



125. BACILLUS SEPTICUS KERATOMALACI^. 



Obtained by Babes (1889) from the broken-down corneal tissues and from 

 the various organs of a child which died of septicaemia following keratoma- 

 lacia. 



Stains with the usual aniline colors ; deeply colored granules may often 

 be seen at the extremities of the rods, or in the middle, in preparations 

 stained with Lofner's solution. 



Morphology. Short, thick bacilli, thinning out at the ends; often united 

 in pairs ; may be surrounded by a capsule. 



Biological Characters. An aerobic and facultative anaerobic, non- 

 liquefying bacillus. Spore formation not observed. Grows in the usual 

 culture media at the room temperature. Upon gelatin plates forms white, 

 slightly elevated, flat colonies with finely dentate margins. In gelatin stick 

 cultures the growth is abundant both on the surface and aiong the line of 

 puncture ; gas bubbles are formed in the gelatin. Upon the surface of agar 

 the growth along the line of inoculation is leaf-like, finely dentate, some- 

 what opalescent, and the culture has a^slightly ammoniacal odor. Upon 

 blood serum a semi-transparent, glistening film is formed, which has dentate 

 margins. 



Pathogenesis. Pathogenic for rabbits and mice, less so for birds; not 

 pathogenic for guinea-pigs. The animals die in from three to seven days. 

 Inoculated into the cornea it causes a purulent keratitis. 



126. BACILLUS SEPTICUS ACUMINATUS. 



Obtained by Babes (1889) from the blood, the umbilical stump, and the 

 various organs of a child which died five days after birth, apparently from 

 septic infection. 



Morphology. Bacilli with lancet-shaped ends, somewhat resembling the 

 bacillus of mouse septicaemia, but thicker. Often shows unstained places in 

 the middle of the rods in stained preparations. 



Stains readily with the usual aniline colors. 



Biological Characters. An aerobic bacillus; does not grow in gelatin at 

 the room temperature. Spore formation not observed. Grows upon blood 

 serum and upon nutrient agar at 37 C., in form of small, flat, circular, 

 transparent, shining colonies, which become confluent and later form a yel- 

 lowish layer. Blood serum is the most favorable medium. 



Pathogenesis. Pathogenic for rabbits and guinea-pigs, not for mice. 

 The animals die in from two to six days, and the bacilli are found in their 

 blood u ml in the various organs. 



127. BACILLUS SEPTICUS ULCERIS GAXGR^ENOSI. 



Obtained by Babes (1889) from the blood and various organs of a boy \vli<> 

 died from septicaemia following gangrene of the skin, etc. 



Morphology. Bacilli with round ends, oval or rod-shaped, about 0.5 to 

 0.6 u thick. 



